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id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Reciprocity (photography)</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang"> <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. 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src="//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Tabell_f%C3%B6r_reciprocitetsfaktorn_-_2022.jpg/220px-Tabell_f%C3%B6r_reciprocitetsfaktorn_-_2022.jpg" decoding="async" width="220" height="326" class="mw-file-element" srcset="//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Tabell_f%C3%B6r_reciprocitetsfaktorn_-_2022.jpg/330px-Tabell_f%C3%B6r_reciprocitetsfaktorn_-_2022.jpg 1.5x, //web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Tabell_f%C3%B6r_reciprocitetsfaktorn_-_2022.jpg/440px-Tabell_f%C3%B6r_reciprocitetsfaktorn_-_2022.jpg 2x" data-file-width="599" data-file-height="888"/></a><figcaption>The specified times apply to black/white film. <br/> <b>Note</b> that the times are approximate, and vary between different films and ASA numbers, but the table shows in general how the exposure time is adjusted.</figcaption></figure> <p>In <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography" title="Photography">photography</a>, <b>reciprocity</b> is the inverse relationship between the intensity and duration of light that determines the reaction of light-sensitive material. Within a normal <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_(photography)" title="Exposure (photography)">exposure</a> range for film stock, for example, the <b>reciprocity law</b> states that the film response will be determined by the total exposure, defined as intensity × time. Therefore, the same response (for example, the <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Optical_density" class="mw-redirect" title="Optical density">optical density</a> of the developed film) can result from reducing duration and increasing light intensity, and vice versa. </p><p>The reciprocal relationship is assumed in most <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Sensitometry" title="Sensitometry">sensitometry</a>, for example when measuring a <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Hurter_and_Driffield" title="Hurter and Driffield">Hurter and Driffield</a> curve (optical density versus logarithm of total exposure) for a photographic emulsion. Total exposure of the film or sensor, the product of focal-plane <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Illuminance" title="Illuminance">illuminance</a> times exposure time, is measured in <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Lux" title="Lux">lux</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Second" title="Second">seconds</a>. </p> <meta property="mw:PageProp/toc"/> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=1" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The idea of reciprocity, once known as Bunsen–Roscoe reciprocity, originated from the work of <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Robert_Bunsen" title="Robert Bunsen">Robert Bunsen</a> and <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Henry_Enfield_Roscoe" class="mw-redirect" title="Henry Enfield Roscoe">Henry Roscoe</a> in 1862.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>Deviations from the reciprocity law were reported by Captain <a href="/web/20241116184711/https://en.wikipedia.org/wiki/William_de_Wiveleslie_Abney" title="William de Wiveleslie Abney">William de Wiveleslie Abney</a> in 1893,<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> and extensively studied by <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Karl_Schwarzschild" title="Karl Schwarzschild">Karl Schwarzschild</a> in 1899.<sup id="cite_ref-schw_5-0" class="reference"><a href="#cite_note-schw-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> Schwarzschild's model was found wanting by Abney and by Englisch,<sup id="cite_ref-shep_8-0" class="reference"><a href="#cite_note-shep-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> and better models have been proposed in subsequent decades of the early twentieth century. In 1913, Kron formulated an equation to describe the effect in terms of curves of constant density,<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> which J. Halm adopted and modified,<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> leading to the "Kron–Halm <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Catenary" title="Catenary">catenary</a> equation"<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> or "Kron–Halm–Webb formula"<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> to describe departures from reciprocity. </p> <div class="mw-heading mw-heading2"><h2 id="In_chemical_photography">In chemical photography</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=2" title="Edit section: In chemical photography"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography" title="Photography">photography</a>, <i>reciprocity</i> refers to the relationship whereby the total light energy – proportional to the total <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_(photography)" title="Exposure (photography)">exposure</a>, the product of the light intensity and exposure time, controlled by <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Aperture" title="Aperture">aperture</a> and <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Shutter_speed" title="Shutter speed">shutter speed</a>, respectively – determines the effect of the light on the film. That is, an increase of brightness by a certain factor is exactly compensated by a decrease of exposure time by the same factor, and vice versa. In other words, there is under normal circumstances a <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Proportionality_(mathematics)" title="Proportionality (mathematics)">reciprocal proportion</a> between aperture area and shutter speed for a given photographic result, with a wider aperture requiring a faster shutter speed for the same effect. For example, an <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_value" title="Exposure value">EV</a> of 10 may be achieved with an aperture (<a href="/web/20241116184711/https://en.wikipedia.org/wiki/F-number" title="F-number">f-number</a>) of <style data-mw-deduplicate="TemplateStyles:r1207775266">.mw-parser-output span.fnumber,.mw-parser-output .fnumber-fallback{display:inline-block;white-space:nowrap;width:max-content}.mw-parser-output span.fnumber::first-letter,.mw-parser-output .fnumber-fallback .first-letter{font-style:italic;font-family:Trebuchet MS,Candara,Georgia,Calibri,Corbel,serif}</style><span class="fnumber-fallback"><span class="first-letter">f</span>/</span>2.8 and a shutter speed of 1/125 <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Second" title="Second">s</a>. The same exposure is achieved by doubling the aperture area to <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1207775266"><span class="fnumber-fallback"><span class="first-letter">f</span>/</span>2 and halving the exposure time to 1/250 s, or by halving the aperture area to <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1207775266"><span class="fnumber-fallback"><span class="first-letter">f</span>/</span>4 and doubling the exposure time to 1/60 s; in each case the response of the film is expected to be the same. </p> <div class="mw-heading mw-heading2"><h2 id="Reciprocity_failure">Reciprocity failure</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=3" title="Edit section: Reciprocity failure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>For most photographic materials, reciprocity is valid with good accuracy over a range of values of exposure duration, but becomes increasingly inaccurate as this range is departed from: this is <b>reciprocity failure</b> (<b>reciprocity law failure</b>, or the <b>Schwarzschild effect</b>).<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> As the light level decreases out of the reciprocity range, the increase in duration, and hence of total exposure, required to produce an equivalent response becomes higher than the formula states; for instance, at half of the light required for a normal exposure, the duration must be more than doubled for the same result. Multipliers used to correct for this effect are called <i>reciprocity factors</i> (see model below). </p><p>At very low light levels, <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_film" title="Photographic film">film</a> is less responsive. Light can be considered to be a stream of <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality" title="Wave–particle duality">discrete photons</a>, and a light-sensitive emulsion is composed of discrete light-sensitive <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_grain" title="Film grain">grains</a>, usually <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Silver_halide" title="Silver halide">silver halide</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Crystal" title="Crystal">crystals</a>. Each grain must absorb a certain number of photons in order for the light-driven reaction to occur and the <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Latent_image" title="Latent image">latent image</a> to form. In particular, if the surface of the silver halide crystal has a cluster of approximately four or more reduced silver atoms, resulting from absorption of a sufficient number of photons (usually a few dozen photons are required), it is rendered developable. At low light levels, <i>i.e.</i> few photons per unit time, photons impinge upon each grain relatively infrequently; if the four photons required arrive over a long enough interval, the partial change due to the first one or two is not stable enough to survive before enough photons arrive to make a permanent <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Latent_image" title="Latent image">latent image</a> center. </p><p>This breakdown in the usual tradeoff between aperture and shutter speed is known as reciprocity failure. Each different film type has a different response at low light levels. Some films are very susceptible to reciprocity failure, and others much less so. Some films that are very light sensitive at normal illumination levels and normal exposure times lose much of their sensitivity at low light levels, becoming effectively "slow" films for long exposures. Conversely some films that are "slow" under normal exposure duration retain their light sensitivity better at low light levels. </p><p>For example, for a given film, if a <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Light_meter" title="Light meter">light meter</a> indicates a required <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_value" title="Exposure value">EV</a> of 5 and the photographer sets the aperture to f/11, then ordinarily a 4-second exposure would be required; a reciprocity correction factor of 1.5 would require the exposure to be extended to 6 seconds for the same result. Reciprocity failure generally becomes significant at exposures of longer than about 1 sec for film, and above 30 sec for paper. </p><p>Reciprocity also breaks down at extremely high levels of illumination with very short exposures. This is a concern for <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Scientific" class="mw-redirect" title="Scientific">scientific</a> and <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Technology" title="Technology">technical</a> photography, but rarely to general <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographer" title="Photographer">photographers</a>, as exposures significantly shorter than a <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Millisecond" title="Millisecond">millisecond</a> are only required for subjects such as <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Explosion" title="Explosion">explosions</a> and in <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Particle_physics" title="Particle physics">particle physics</a>, or when taking high-speed motion pictures with very high shutter speeds (1/10,000 sec or faster). </p> <div class="mw-heading mw-heading2"><h2 id="Schwarzschild_law"><span class="anchor" id="Schwarzschild_law"></span>Schwarzschild law</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=4" title="Edit section: Schwarzschild law"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In response to astronomical observations of low intensity reciprocity failure, <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Karl_Schwarzschild" title="Karl Schwarzschild">Karl Schwarzschild</a> wrote (circa 1900): </p> <dl><dd>"In determinations of stellar brightness by the photographic method I have recently been able to confirm once more the existence of such deviations, and to follow them up in a quantitative way, and to express them in the following rule, which should replace the law of reciprocity: Sources of light of different intensity <i>I</i> cause the same degree of blackening under different exposures <i>t</i> if the products <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle I\times t^{0.86}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>I</mi> <mo>×</mo> <msup> <mi>t</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0.86</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle I\times t^{0.86}}</annotation> </semantics> </math></span><img src="https://web.archive.org/web/20241116184711im_/https://wikimedia.org/api/rest_v1/media/math/render/svg/07153efbc7b2094bfd20d350db5002d0c4e09cb8" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:8.007ex; height:2.676ex;" alt="{\displaystyle I\times t^{0.86}}"></span> are equal."<sup id="cite_ref-schw_5-1" class="reference"><a href="#cite_note-schw-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup></dd></dl> <p>Unfortunately, Schwarzschild's empirically determined <i>0.86</i> coefficient turned out to be of limited usefulness.<sup id="cite_ref-martin_15-0" class="reference"><a href="#cite_note-martin-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> A modern formulation of <b>Schwarzschild's law</b> is given as </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E=It^{p}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>E</mi> <mo>=</mo> <mi>I</mi> <msup> <mi>t</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>p</mi> </mrow> </msup> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle E=It^{p}\ }</annotation> </semantics> </math></span><img src="https://web.archive.org/web/20241116184711im_/https://wikimedia.org/api/rest_v1/media/math/render/svg/eb26d937cf6970f19e14316d3dcbc3e14820c195" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:8.525ex; height:2.343ex;" alt="{\displaystyle E=It^{p}\ }"></span></dd></dl> <p>where <i>E</i> is a measure of the "effect of the exposure" that leads to changes in the <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Opacity_(optics)" class="mw-redirect" title="Opacity (optics)">opacity</a> of the photosensitive material (in the same degree that an equal value of exposure <i>H = It</i> does in the reciprocity region), <i>I</i> is <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Illuminance" title="Illuminance">illuminance</a>, <i>t</i> is <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_duration" class="mw-redirect" title="Exposure duration">exposure duration</a> and <i>p</i> is the <i>Schwarzschild coefficient</i>.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p><p>However, a constant value for <i>p</i> remains elusive, and has not replaced the need for more realistic models or empirical sensitometric data in critical applications.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> When reciprocity holds, Schwarzschild's law uses <i>p</i> = 1.0. </p><p>Since the Schwarzschild's law formula gives unreasonable values for times in the region where reciprocity holds, a modified formula has been found that fits better across a wider range of exposure times. The modification is in terms of a factor the multiplies the ISO <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_speed" title="Film speed">film speed</a>:<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </p> <dl><dd>Relative film speed <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle =(t+1)^{(p-1)}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>=</mo> <mo stretchy="false">(</mo> <mi>t</mi> <mo>+</mo> <mn>1</mn> <msup> <mo stretchy="false">)</mo> <mrow class="MJX-TeXAtom-ORD"> <mo stretchy="false">(</mo> <mi>p</mi> <mo>−</mo> <mn>1</mn> <mo stretchy="false">)</mo> </mrow> </msup> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle =(t+1)^{(p-1)}\ }</annotation> </semantics> </math></span><img src="https://web.archive.org/web/20241116184711im_/https://wikimedia.org/api/rest_v1/media/math/render/svg/3b5e3e1fb3b3717430b704553be6a4901aa3510e" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:14.125ex; height:3.343ex;" alt="{\displaystyle =(t+1)^{(p-1)}\ }"></span></dd></dl> <p>where the <i>t</i> + 1 term implies a breakpoint near 1 second separating the region where reciprocity holds from the region where it fails. </p> <div class="mw-heading mw-heading3"><h3 id="Simple_model_for_t_>_1_second"><span id="Simple_model_for_t_.3E_1_second"></span>Simple model for <i>t</i> > 1 second</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=5" title="Edit section: Simple model for t > 1 second"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Some models of microscope use automatic electronic models for reciprocity failure compensation, generally of a form for correct time, <i>T<sub>c</sub></i>, expressible as a <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Power_law" title="Power law">power law</a> of metered time, <i>T<sub>m</sub></i>, that is, <i>T<sub>c</sub>=(T<sub>m</sub>)<sup>p</sup></i>, for times in seconds. Typical values of <i>p</i> are 1.25 to 1.45, but some are low as 1.1 and high as 1.8.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="The_Kron–Halm_catenary_equation"><span id="The_Kron.E2.80.93Halm_catenary_equation"></span>The Kron–Halm catenary equation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=6" title="Edit section: The Kron–Halm catenary equation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Kron's equation as modified by Halm states that the response of the film is a function of <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle It/\psi \ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>I</mi> <mi>t</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>/</mo> </mrow> <mi>ψ</mi> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle It/\psi \ }</annotation> </semantics> </math></span><img src="https://web.archive.org/web/20241116184711im_/https://wikimedia.org/api/rest_v1/media/math/render/svg/a8968c8b8408414bf744f961770de12038b2a1ea" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.268ex; height:2.843ex;" alt="{\displaystyle It/\psi \ }"></span>, with the factor defined by a <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Catenary" title="Catenary">catenary</a> (<a href="/web/20241116184711/https://en.wikipedia.org/wiki/Hyperbolic_cosine" class="mw-redirect" title="Hyperbolic cosine">hyperbolic cosine</a>) equation accounting for reciprocity failure at both very high and very low intensities: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi ={\frac {1}{2}}[(I/I_{0})^{a}+(I/I_{0})^{-a}]}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>ψ</mi> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> </mrow> <mo stretchy="false">[</mo> <mo stretchy="false">(</mo> <mi>I</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>/</mo> </mrow> <msub> <mi>I</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> <msup> <mo stretchy="false">)</mo> <mrow class="MJX-TeXAtom-ORD"> <mi>a</mi> </mrow> </msup> <mo>+</mo> <mo stretchy="false">(</mo> <mi>I</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>/</mo> </mrow> <msub> <mi>I</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>0</mn> </mrow> </msub> <msup> <mo stretchy="false">)</mo> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mi>a</mi> </mrow> </msup> <mo stretchy="false">]</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi ={\frac {1}{2}}[(I/I_{0})^{a}+(I/I_{0})^{-a}]}</annotation> </semantics> </math></span><img src="https://web.archive.org/web/20241116184711im_/https://wikimedia.org/api/rest_v1/media/math/render/svg/e04699ee29d00bf553f3b9b4431edcdd5085bc3f" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:26.668ex; height:5.176ex;" alt="{\displaystyle \psi ={\frac {1}{2}}[(I/I_{0})^{a}+(I/I_{0})^{-a}]}"></span></dd></dl> <p>where <i>I</i><sub>0</sub> is the photographic material's optimum intensity level and <i>a</i> is a constant that characterizes the material's reciprocity failure.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Quantum_reciprocity-failure_model">Quantum reciprocity-failure model</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=7" title="Edit section: Quantum reciprocity-failure model"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Modern models of reciprocity failure incorporate an <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exponential_function" title="Exponential function">exponential function</a>, as opposed to <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Power_law" title="Power law">power law</a>, dependence on time or intensity at long exposure times or low intensities, based on the distribution of <i>interquantic times</i> (times between photon absorptions in a grain) and the temperature-dependent <i>lifetimes</i> of the intermediate states of the partially exposed grains.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p><p>Baines and Bomback<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> explain the "low intensity inefficiency" this way: </p> <style data-mw-deduplicate="TemplateStyles:r1244412712">.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 32px}.mw-parser-output .templatequotecite{line-height:1.5em;text-align:left;margin-top:0}@media(min-width:500px){.mw-parser-output .templatequotecite{padding-left:1.6em}}</style><blockquote class="templatequote"> <p>Electrons are released at a very low rate. They are trapped and neutralised and must remain as isolated silver atoms for much longer than in normal latent image formation. It has already been observed that such extreme sub-latent image is unstable, and it is postulated that ineffiency is caused by many isolated atoms of silver losing their acquired electrons during the period of instability. </p> </blockquote> <div class="mw-heading mw-heading2"><h2 id="Astrophotography">Astrophotography</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=8" title="Edit section: Astrophotography"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Reciprocity failure is an important effect in the field of film-based <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Astrophotography" title="Astrophotography">astrophotography</a>. Deep-sky objects such as galaxies and nebulae are often so faint that they are not visible to the un-aided eye. To make matters worse, many objects' spectra do not line up with the film emulsion's sensitivity curves. Many of these targets are small and require long focal lengths, which can push the focal ratio far above <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1207775266"><span class="fnumber-fallback"><span class="first-letter">f</span>/</span>5. Combined, these parameters make these targets extremely difficult to capture with film; exposures from 30 minutes to well over an hour are typical. As a typical example, capturing an image of the <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Andromeda_Galaxy" title="Andromeda Galaxy">Andromeda Galaxy</a> at <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1207775266"><span class="fnumber-fallback"><span class="first-letter">f</span>/</span>4 will take about 30 minutes; to get the same density at <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1207775266"><span class="fnumber-fallback"><span class="first-letter">f</span>/</span>8 would require an exposure of about 200 minutes. </p><p>When a telescope is tracking an object, every minute is difficult; therefore, reciprocity failure is one of the biggest motivations for astronomers to switch to <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_imaging" title="Digital imaging">digital imaging</a>. Electronic <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Image_sensor" title="Image sensor">image sensors</a> have their own limitation at long exposure time and low illuminance levels, not usually referred to as reciprocity failure, namely noise from <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Dark_current_(physics)" title="Dark current (physics)">dark current</a>, but this effect can be controlled by cooling the sensor. </p> <div class="mw-heading mw-heading2"><h2 id="Holography">Holography</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=9" title="Edit section: Holography"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A similar problem exists in <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Holography" title="Holography">holography</a>. The total energy required when exposing holographic film using a continuous wave <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Laser" title="Laser">laser</a> (i.e. for several seconds) is significantly less than the total energy required when exposing holographic film using a pulsed <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Laser" title="Laser">laser</a> (i.e. around 20–40 <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Nanosecond" title="Nanosecond">nanoseconds</a>) due to a reciprocity failure. It can also be caused by very long or very short exposures with a continuous wave laser. To try to offset the reduced brightness of the film due to reciprocity failure, a method called <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Latensification" title="Latensification">latensification</a> can be used. This is usually done directly after the holographic exposure and using an incoherent light source (such as a 25–40 W light bulb). Exposing the holographic film to the light for a few seconds can increase the brightness of the hologram by an order of magnitude. </p> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=10" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"> <style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFHolger_PetterssonGustav_Konrad_von_SchulthessDavid_J._AllisonHans-Jørgen_Smith1998" class="citation book cs1">Holger Pettersson; Gustav Konrad von Schulthess; David J. Allison & Hans-Jørgen Smith (1998). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=zvDY5unRC4oC&dq=Bunsen+Roscoe+reciprocity&pg=PA59"><i>The Encyclopaedia of Medical Imaging</i></a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Taylor_%26_Francis" title="Taylor & Francis">Taylor & Francis</a>. p. 59. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-1-901865-13-4" title="Special:BookSources/978-1-901865-13-4"><bdi>978-1-901865-13-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Encyclopaedia+of+Medical+Imaging&rft.pages=59&rft.pub=Taylor+%26+Francis&rft.date=1998&rft.isbn=978-1-901865-13-4&rft.au=Holger+Pettersson&rft.au=Gustav+Konrad+von+Schulthess&rft.au=David+J.+Allison&rft.au=Hans-J%C3%B8rgen+Smith&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DzvDY5unRC4oC%26dq%3DBunsen%2BRoscoe%2Breciprocity%26pg%3DPA59&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGeoffrey_G._Atteridge2000" class="citation book cs1">Geoffrey G. Atteridge (2000). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=MblHnLN2N2kC&dq=Bunsen+Roscoe+reciprocity+intitle:manual&pg=PA238">"Sensitometry"</a>. In Ralph E. Jacobson; Sidney F. Ray; Geoffrey G. Atteridge; Norman R. Axford (eds.). <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://archive.org/details/digitalvideocame00pete/page/238"><i>The Manual of Photography: Photographic and Digital Imaging</i></a></span> (9th ed.). Oxford: Focal Press. p. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://archive.org/details/digitalvideocame00pete/page/238">238</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-240-51574-8" title="Special:BookSources/978-0-240-51574-8"><bdi>978-0-240-51574-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Sensitometry&rft.btitle=The+Manual+of+Photography%3A+Photographic+and+Digital+Imaging&rft.pages=238&rft.edition=9th&rft.pub=Oxford%3A+Focal+Press&rft.date=2000&rft.isbn=978-0-240-51574-8&rft.au=Geoffrey+G.+Atteridge&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DMblHnLN2N2kC%26dq%3DBunsen%2BRoscoe%2Breciprocity%2Bintitle%3Amanual%26pg%3DPA238&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFR.W._BunsenH.E._Roscoe1862" class="citation journal cs1">R.W. Bunsen; H.E. Roscoe (1862). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://zenodo.org/record/1432041">"Photochemical Researches – Part V. On the Measurement of the Chemical Action of Direct and Diffuse Sunlight"</a>. <i>Proceedings of the Royal Society</i>. <b>12</b>: 306–312. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1862RSPS...12..306B">1862RSPS...12..306B</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1098%2Frspl.1862.0069">10.1098/rspl.1862.0069</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Proceedings+of+the+Royal+Society&rft.atitle=Photochemical+Researches+%E2%80%93+Part+V.+On+the+Measurement+of+the+Chemical+Action+of+Direct+and+Diffuse+Sunlight&rft.volume=12&rft.pages=306-312&rft.date=1862&rft_id=info%3Adoi%2F10.1098%2Frspl.1862.0069&rft_id=info%3Abibcode%2F1862RSPS...12..306B&rft.au=R.W.+Bunsen&rft.au=H.E.+Roscoe&rft_id=https%3A%2F%2Fzenodo.org%2Frecord%2F1432041&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFW._de_W._Abney1893" class="citation journal cs1">W. de W. Abney (1893). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1098%2Frspl.1893.0060">"On a failure of the law in photography that when the products of the intensity of the light acting and of the time of exposure are equal, equal amounts of chemical action will be produced"</a>. <i>Proceedings of the Royal Society</i>. <b>54</b> (326–330): 143–147. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1893RSPS...54..143A">1893RSPS...54..143A</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1098%2Frspl.1893.0060">10.1098/rspl.1893.0060</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Proceedings+of+the+Royal+Society&rft.atitle=On+a+failure+of+the+law+in+photography+that+when+the+products+of+the+intensity+of+the+light+acting+and+of+the+time+of+exposure+are+equal%2C+equal+amounts+of+chemical+action+will+be+produced&rft.volume=54&rft.issue=326%E2%80%93330&rft.pages=143-147&rft.date=1893&rft_id=info%3Adoi%2F10.1098%2Frspl.1893.0060&rft_id=info%3Abibcode%2F1893RSPS...54..143A&rft.au=W.+de+W.+Abney&rft_id=https%3A%2F%2Fdoi.org%2F10.1098%252Frspl.1893.0060&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-schw-5"><span class="mw-cite-backlink">^ <a href="#cite_ref-schw_5-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-schw_5-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">K. Schwarzschild "On The Deviations From The Law of Reciprocity For Bromide Of Silver Gelatine" <i>The Astrophysical Journal</i> vol.11 (1900) p.89 <a rel="nofollow" class="external autonumber" href="https://web.archive.org/web/20241116184711/http://articles.adsabs.harvard.edu/full/1900ApJ....11...89S">[1]</a></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFS._E._SheppardC._E._Kenneth_Mees1907" class="citation book cs1">S. E. Sheppard & C. E. Kenneth Mees (1907). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://archive.org/details/investigationso01meesgoog"><i>Investigations on the Theory of the Photographic Process</i></a>. Longmans, Green and Co. p. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://archive.org/details/investigationso01meesgoog/page/n232">214</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-240-50694-4" title="Special:BookSources/978-0-240-50694-4"><bdi>978-0-240-50694-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Investigations+on+the+Theory+of+the+Photographic+Process&rft.pages=214&rft.pub=Longmans%2C+Green+and+Co&rft.date=1907&rft.isbn=978-0-240-50694-4&rft.au=S.+E.+Sheppard&rft.au=C.+E.+Kenneth+Mees&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Finvestigationso01meesgoog&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRalph_W._LambrechtChris_Woodhouse2003" class="citation book cs1">Ralph W. Lambrecht & Chris Woodhouse (2003). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=Q7M0zOHcUxsC&dq=Abney+Schwarzschild+reciprocity+failure&pg=PA113"><i>Way Beyond Monochrome</i></a>. Newpro UK Ltd. p. 113. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-86343-354-2" title="Special:BookSources/978-0-86343-354-2"><bdi>978-0-86343-354-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Way+Beyond+Monochrome&rft.pages=113&rft.pub=Newpro+UK+Ltd&rft.date=2003&rft.isbn=978-0-86343-354-2&rft.au=Ralph+W.+Lambrecht&rft.au=Chris+Woodhouse&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DQ7M0zOHcUxsC%26dq%3DAbney%2BSchwarzschild%2Breciprocity%2Bfailure%26pg%3DPA113&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-shep-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-shep_8-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSamuel_Edward_SheppardCharles_Edward_Kenneth_Mees1907" class="citation book cs1">Samuel Edward Sheppard & Charles Edward Kenneth Mees (1907). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://archive.org/details/investigationso01meesgoog"><i>Investigations on the theory of the photographic process</i></a>. Longmans, Green and Co. pp. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://archive.org/details/investigationso01meesgoog/page/n232">214</a>–215.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Investigations+on+the+theory+of+the+photographic+process&rft.pages=214-215&rft.pub=Longmans%2C+Green+and+Co&rft.date=1907&rft.au=Samuel+Edward+Sheppard&rft.au=Charles+Edward+Kenneth+Mees&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Finvestigationso01meesgoog&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFErich_Kron1913" class="citation journal cs1">Erich Kron (1913). "Über das Schwärzungsgesetz Photographischer Platten". <i>Publikationen des Astrophysikalischen Observatoriums zu Potsdam</i>. <b>22</b> (67). <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1913POPot..67.....K">1913POPot..67.....K</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Publikationen+des+Astrophysikalischen+Observatoriums+zu+Potsdam&rft.atitle=%C3%9Cber+das+Schw%C3%A4rzungsgesetz+Photographischer+Platten&rft.volume=22&rft.issue=67&rft.date=1913&rft_id=info%3Abibcode%2F1913POPot..67.....K&rft.au=Erich+Kron&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLoyd_A._Jones1927" class="citation journal cs1">Loyd A. Jones (July 1927). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=Zi0rAAAAYAAJ&dq=Kron+catenary+reciprocity&pg=PA111">"Photographic Spectrophotometry in the Ultra-Violet Region"</a>. <i>Bulletin of the National Research Council</i>. <b>8</b> (1): 109–123. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1927TrAGU...8..109J">1927TrAGU...8..109J</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1029%2FTR008i001p00109">10.1029/TR008i001p00109</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Bulletin+of+the+National+Research+Council&rft.atitle=Photographic+Spectrophotometry+in+the+Ultra-Violet+Region&rft.volume=8&rft.issue=1&rft.pages=109-123&rft.date=1927-07&rft_id=info%3Adoi%2F10.1029%2FTR008i001p00109&rft_id=info%3Abibcode%2F1927TrAGU...8..109J&rft.au=Loyd+A.+Jones&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DZi0rAAAAYAAJ%26dq%3DKron%2Bcatenary%2Breciprocity%26pg%3DPA111&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJ._Halm1915" class="citation journal cs1">J. Halm (Jan 1915). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1093%2Fmnras%2F75.3.150">"On the Determination of Fundamental Photographic Magnitudes"</a>. <i>Monthly Notices of the Royal Astronomical Society</i>. <b>75</b> (3): 150–177. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1915MNRAS..75..150H">1915MNRAS..75..150H</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1093%2Fmnras%2F75.3.150">10.1093/mnras/75.3.150</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=On+the+Determination+of+Fundamental+Photographic+Magnitudes&rft.volume=75&rft.issue=3&rft.pages=150-177&rft.date=1915-01&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F75.3.150&rft_id=info%3Abibcode%2F1915MNRAS..75..150H&rft.au=J.+Halm&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fmnras%252F75.3.150&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJ._H._Webb1935" class="citation journal cs1">J. H. Webb (1935). "The Effect of Temperature upon Reciprocity Law Failure in Photographic Exposure". <i>Journal of the Optical Society of America</i>. <b>25</b> (1): 4–20. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1935JOSA...25....4W">1935JOSA...25....4W</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1364%2FJOSA.25.000004">10.1364/JOSA.25.000004</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+the+Optical+Society+of+America&rft.atitle=The+Effect+of+Temperature+upon+Reciprocity+Law+Failure+in+Photographic+Exposure&rft.volume=25&rft.issue=1&rft.pages=4-20&rft.date=1935&rft_id=info%3Adoi%2F10.1364%2FJOSA.25.000004&rft_id=info%3Abibcode%2F1935JOSA...25....4W&rft.au=J.+H.+Webb&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFErnst_Katz1941" class="citation book cs1">Ernst Katz (1941). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=B-cyAAAAMAAJ&q=Kron-halm"><i>Contribution to the Understanding of Latent Image Formation in Photography</i></a>. Drukkerij F. Schotanus & Jens. p. 11.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Contribution+to+the+Understanding+of+Latent+Image+Formation+in+Photography&rft.pages=11&rft.pub=Drukkerij+F.+Schotanus+%26+Jens&rft.date=1941&rft.au=Ernst+Katz&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DB-cyAAAAMAAJ%26q%3DKron-halm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRudolph_SeckDennis_H._Laney1983" class="citation book cs1">Rudolph Seck & Dennis H. Laney (1983). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=x6NsV74MSDYC&dq=%22Schwarzschild+effect%22&pg=PA183"><i>Leica Darkroom Practice</i></a>. MBI Publishing Company. p. 183. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-906447-24-6" title="Special:BookSources/978-0-906447-24-6"><bdi>978-0-906447-24-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Leica+Darkroom+Practice&rft.pages=183&rft.pub=MBI+Publishing+Company&rft.date=1983&rft.isbn=978-0-906447-24-6&rft.au=Rudolph+Seck&rft.au=Dennis+H.+Laney&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3Dx6NsV74MSDYC%26dq%3D%2522Schwarzschild%2Beffect%2522%26pg%3DPA183&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-martin-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-martin_15-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJonathan_W._MartinJoannie_W._ChinTinh_Nguyen2003" class="citation journal cs1">Jonathan W. Martin; Joannie W. Chin; Tinh Nguyen (2003). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/http://fire.nist.gov/bfrlpubs/build03/PDF/b03051.pdf">"Reciprocity law experiments in polymeric photodegradation: a critical review"</a> <span class="cs1-format">(PDF)</span>. <i>Progress in Organic Coatings</i>. <b>47</b> (3–4): 294. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/CiteSeerX_(identifier)" class="mw-redirect" title="CiteSeerX (identifier)">CiteSeerX</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.332.6705">10.1.1.332.6705</a></span>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1016%2Fj.porgcoat.2003.08.002">10.1016/j.porgcoat.2003.08.002</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Progress+in+Organic+Coatings&rft.atitle=Reciprocity+law+experiments+in+polymeric+photodegradation%3A+a+critical+review&rft.volume=47&rft.issue=3%E2%80%934&rft.pages=294&rft.date=2003&rft_id=https%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fsummary%3Fdoi%3D10.1.1.332.6705%23id-name%3DCiteSeerX&rft_id=info%3Adoi%2F10.1016%2Fj.porgcoat.2003.08.002&rft.au=Jonathan+W.+Martin&rft.au=Joannie+W.+Chin&rft.au=Tinh+Nguyen&rft_id=http%3A%2F%2Ffire.nist.gov%2Fbfrlpubs%2Fbuild03%2FPDF%2Fb03051.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWalter_Clark2007" class="citation book cs1">Walter Clark (2007). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=sRxVz6J09VQC&dq=schwarzschild%27s-law&pg=PA62"><i>Photography by Infrared – Its Principles and Applications</i></a>. Read Books. p. 62. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-1-4067-4486-6" title="Special:BookSources/978-1-4067-4486-6"><bdi>978-1-4067-4486-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Photography+by+Infrared+%E2%80%93+Its+Principles+and+Applications&rft.pages=62&rft.pub=Read+Books&rft.date=2007&rft.isbn=978-1-4067-4486-6&rft.au=Walter+Clark&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DsRxVz6J09VQC%26dq%3Dschwarzschild%2527s-law%26pg%3DPA62&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGraham_Saxby2002" class="citation book cs1">Graham Saxby (2002). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=e5mC5TXlBw8C&dq=reciprocity-failure+effective-exposure&pg=PA141"><i>The Science of Imaging</i></a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/CRC_Press" title="CRC Press">CRC Press</a>. p. 141. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-7503-0734-5" title="Special:BookSources/978-0-7503-0734-5"><bdi>978-0-7503-0734-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Science+of+Imaging&rft.pages=141&rft.pub=CRC+Press&rft.date=2002&rft.isbn=978-0-7503-0734-5&rft.au=Graham+Saxby&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3De5mC5TXlBw8C%26dq%3Dreciprocity-failure%2Beffective-exposure%26pg%3DPA141&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text">J.W. Martin et al. "Reciprocity law experiments in polymeric photodegradation: a critical review", <i>Progress in Organic Coatings</i> 47 (2003) pp.306 <a rel="nofollow" class="external autonumber" href="https://web.archive.org/web/20241116184711/http://fire.nist.gov/bfrlpubs/build03/PDF/b03051.pdf">[2]</a></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMichael_A._Covington1999" class="citation book cs1">Michael A. Covington (1999). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=tzXv4WrvZ-EC&dq=reciprocity+failure+exposure+time+compensation+formula&pg=PA181"><i>Astrophotography for the amateur</i></a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Cambridge_University_Press" title="Cambridge University Press">Cambridge University Press</a>. p. 181. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-521-62740-5" title="Special:BookSources/978-0-521-62740-5"><bdi>978-0-521-62740-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Astrophotography+for+the+amateur&rft.pages=181&rft.pub=Cambridge+University+Press&rft.date=1999&rft.isbn=978-0-521-62740-5&rft.au=Michael+A.+Covington&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DtzXv4WrvZ-EC%26dq%3Dreciprocity%2Bfailure%2Bexposure%2Btime%2Bcompensation%2Bformula%26pg%3DPA181&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFred_RostRon_Oldfield2000" class="citation book cs1">Fred Rost & Ron Oldfield (2000). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=IaQOh28E0vgC&dq=%22reciprocity+model%22+%22print+film%22&pg=PA204"><i>Photography with a Microscope</i></a>. Cambridge University Press. p. 204. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-0-521-77096-5" title="Special:BookSources/978-0-521-77096-5"><bdi>978-0-521-77096-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Photography+with+a+Microscope&rft.pages=204&rft.pub=Cambridge+University+Press&rft.date=2000&rft.isbn=978-0-521-77096-5&rft.au=Fred+Rost&rft.au=Ron+Oldfield&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DIaQOh28E0vgC%26dq%3D%2522reciprocity%2Bmodel%2522%2B%2522print%2Bfilm%2522%26pg%3DPA204&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFW._M._H._Greaves1936" class="citation journal cs1">W. M. H. Greaves (1936). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1093%2Fmnras%2F96.9.825">"Time Effects in Spectrophotometry"</a>. <i>Monthly Notices of the Royal Astronomical Society</i>. <b>96</b> (9): 825–832. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://ui.adsabs.harvard.edu/abs/1936MNRAS..96..825G">1936MNRAS..96..825G</a>. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1093%2Fmnras%2F96.9.825">10.1093/mnras/96.9.825</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=Time+Effects+in+Spectrophotometry&rft.volume=96&rft.issue=9&rft.pages=825-832&rft.date=1936&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F96.9.825&rft_id=info%3Abibcode%2F1936MNRAS..96..825G&rft.au=W.+M.+H.+Greaves&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fmnras%252F96.9.825&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFW._J._Anderson1987" class="citation book cs1">W. J. Anderson (1987). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=suVRUSRyW_cC&dq=reciprocity-failure++interarrival-times+thermal-decay+low-intensity&pg=PA14">"Probabilistic Models of the Photographic Process"</a>. In Ian B. MacNeill (ed.). <i>Applied Probability, Stochastic Processes, and Sampling Theory: Advances in the Statistical Sciences</i>. Springer. pp. 9–40. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:BookSources/978-90-277-2393-2" title="Special:BookSources/978-90-277-2393-2"><bdi>978-90-277-2393-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Probabilistic+Models+of+the+Photographic+Process&rft.btitle=Applied+Probability%2C+Stochastic+Processes%2C+and+Sampling+Theory%3A+Advances+in+the+Statistical+Sciences&rft.pages=9-40&rft.pub=Springer&rft.date=1987&rft.isbn=978-90-277-2393-2&rft.au=W.+J.+Anderson&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DsuVRUSRyW_cC%26dq%3Dreciprocity-failure%2B%2Binterarrival-times%2Bthermal-decay%2Blow-intensity%26pg%3DPA14&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCollins1956–1957" class="citation journal cs1">Collins, Ronald Bernard (1956–1957). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=aCgJAAAAIAAJ&q=reciprocity-failure+exponential">"(Page 65 of)"</a>. <i>The Journal of Photographic Science</i>. <b>4–5</b>: 65.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Journal+of+Photographic+Science&rft.atitle=%28Page+65+of%29&rft.volume=4-5&rft.pages=65&rft.date=1956%2F1957&rft.aulast=Collins&rft.aufirst=Ronald+Bernard&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DaCgJAAAAIAAJ%26q%3Dreciprocity-failure%2Bexponential&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJ._H._Webb1950" class="citation journal cs1">J. H. Webb (1950). "Low Intensity Reciprocity-Law Failure in Photographic Exposure: Energy Depth of Electron Traps in Latent-Image Formation; Number of Quanta Required to Form the Stable Sublatent Image". <i>Journal of the Optical Society of America</i>. <b>40</b> (1): 3–13. <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://doi.org/10.1364%2FJOSA.40.000003">10.1364/JOSA.40.000003</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+the+Optical+Society+of+America&rft.atitle=Low+Intensity+Reciprocity-Law+Failure+in+Photographic+Exposure%3A+Energy+Depth+of+Electron+Traps+in+Latent-Image+Formation%3B+Number+of+Quanta+Required+to+Form+the+Stable+Sublatent+Image&rft.volume=40&rft.issue=1&rft.pages=3-13&rft.date=1950&rft_id=info%3Adoi%2F10.1364%2FJOSA.40.000003&rft.au=J.+H.+Webb&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHarry_BainesEdward_S._Bomback1967" class="citation book cs1">Harry Baines & Edward S. Bomback (1967). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/https://books.google.com/books?id=QNxTAAAAMAAJ&q=%22sub-latent+image+is+unstable%22"><i>The Science of Photography</i></a> (2nd ed.). Fountain Press. p. 202.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Science+of+Photography&rft.pages=202&rft.edition=2nd&rft.pub=Fountain+Press&rft.date=1967&rft.au=Harry+Baines&rft.au=Edward+S.+Bomback&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DQNxTAAAAMAAJ%26q%3D%2522sub-latent%2Bimage%2Bis%2Bunstable%2522&rfr_id=info%3Asid%2Fen.wikipedia.org%3AReciprocity+%28photography%29" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/web/20241116184711/https://en.wikipedia.org/w/index.php?title=Reciprocity_(photography)&action=edit&section=11" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/http://www.earthboundlight.com/phototips/reciprocity-what.html"><i>Reciprocity what?</i></a> – a brief explanation in layman's terms.</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20241116184711/http://mkaz.com/photo/tools/reciprocity.html">Reciprocity charts for slides and black & white</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist 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.navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Photography" style="padding:3px"><table class="nowraplinks mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Template:Photography" title="Template:Photography"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Template_talk:Photography" title="Template talk:Photography"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Special:EditPage/Template:Photography" title="Special:EditPage/Template:Photography"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Photography" style="font-size:114%;margin:0 4em"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography" title="Photography">Photography</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Equipment</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Camera" title="Camera">Camera</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Light_field_camera" title="Light field camera">light-field</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_camera" title="Digital camera">digital</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Field_camera" title="Field camera">field</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Instant_camera" title="Instant camera">instant</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Camera_phone" title="Camera phone">phone</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Pinhole_camera" title="Pinhole camera">pinhole</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Press_camera" title="Press camera">press</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Rangefinder_camera" title="Rangefinder camera">rangefinder</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Single-lens_reflex_camera" title="Single-lens reflex camera">SLR</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Camera" title="Camera">still</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Twin-lens_reflex_camera" title="Twin-lens reflex camera">TLR</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Toy_camera" title="Toy camera">toy</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/View_camera" title="View camera">view</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Darkroom" title="Darkroom">Darkroom</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Enlarger" title="Enlarger">enlarger</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Safelight" title="Safelight">safelight</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_film" title="Photographic film">Film</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_base" title="Film base">base</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_format" title="Film format">format</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_holder" title="Film holder">holder</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_stock" title="Film stock">stock</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_photographic_films" title="List of photographic films">available films</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_discontinued_photographic_films" title="List of discontinued photographic films">discontinued films</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_filter" title="Photographic filter">Filter</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Flash_(photography)" title="Flash (photography)">Flash</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Beauty_dish" title="Beauty dish">beauty dish</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Cucoloris" title="Cucoloris">cucoloris</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Gobo_(lighting)" title="Gobo (lighting)">gobo</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Hot_shoe" title="Hot shoe">hot shoe</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Lens_hood" title="Lens hood">lens hood</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Monolight" title="Monolight">monolight</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Reflector_(photography)" title="Reflector (photography)">reflector</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Snoot" title="Snoot">snoot</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Softbox" title="Softbox">softbox</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Camera_lens" title="Camera lens">Lens</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Long-focus_lens" title="Long-focus lens">long-focus</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Prime_lens" title="Prime lens">prime</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Zoom_lens" title="Zoom lens">zoom</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Wide-angle_lens" title="Wide-angle lens">wide-angle</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Fisheye_lens" title="Fisheye lens">fisheye</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Swivel_lens" title="Swivel lens">swivel</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Telephoto_lens" title="Telephoto lens">telephoto</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_photographic_equipment_makers" title="List of photographic equipment makers">Manufacturers</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Monopod" title="Monopod">Monopod</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Movie_projector" title="Movie projector">Movie projector</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Slide_projector" title="Slide projector">Slide projector</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Tripod_(photography)" title="Tripod (photography)">Tripod</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Tripod_head" title="Tripod head">head</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Zone_plate" title="Zone plate">Zone plate</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Terminology</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/35_mm_equivalent_focal_length" title="35 mm equivalent focal length">35 mm equivalent focal length</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Angle_of_view_(photography)" title="Angle of view (photography)">Angle of view</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Aperture" title="Aperture">Aperture</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Backscatter_(photography)" title="Backscatter (photography)">Backscatter</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Black-and-white" title="Black-and-white">Black-and-white</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Chromatic_aberration" title="Chromatic aberration">Chromatic aberration</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Circle_of_confusion" title="Circle of confusion">Circle of confusion</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Clipping_(photography)" title="Clipping (photography)">Clipping</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Color_balance" title="Color balance">Color balance</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Color_temperature" title="Color temperature">Color temperature</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Depth_of_field" title="Depth of field">Depth of field</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Depth_of_focus" title="Depth of focus">Depth of focus</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_(photography)" title="Exposure (photography)">Exposure</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_compensation" title="Exposure compensation">Exposure compensation</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposure_value" title="Exposure value">Exposure value</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Zebra_patterning" title="Zebra patterning">Zebra patterning</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/F-number" title="F-number">F-number</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_format" title="Film format">Film format</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Large_format" title="Large format">large</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Medium_format" title="Medium format">medium</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_speed" title="Film speed">Film speed</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Focal_length" title="Focal length">Focal length</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Guide_number" title="Guide number">Guide number</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Hyperfocal_distance" title="Hyperfocal distance">Hyperfocal distance</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Lens_flare" title="Lens flare">Lens flare</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Metering_mode" title="Metering mode">Metering mode</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Perspective_distortion" title="Perspective distortion">Perspective distortion</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photograph" title="Photograph">Photograph</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_printing" title="Photographic printing">Photographic printing</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Albumen_print" title="Albumen print">Albumen</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_photographic_processes" title="List of photographic processes">Photographic processes</a></li> <li><a class="mw-selflink selflink">Reciprocity</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Red-eye_effect" title="Red-eye effect">Red-eye effect</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Science_of_photography" title="Science of photography">Science of photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Shutter_speed" title="Shutter speed">Shutter speed</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Flash_synchronization" title="Flash synchronization">Sync</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Zone_System" title="Zone System">Zone System</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Genres</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Abstract_photography" title="Abstract photography">Abstract</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Aerial_photography" title="Aerial photography">Aerial</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Aircraft_spotting" title="Aircraft spotting">Aircraft</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Architectural_photography" title="Architectural photography">Architectural</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Astrophotography" title="Astrophotography">Astrophotography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Banquet_photography" title="Banquet photography">Banquet</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Candid_photography" title="Candid photography">Candid</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Conceptual_photography" title="Conceptual photography">Conceptual</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Conservation_photography" title="Conservation photography">Conservation</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Cloudscape_photography" title="Cloudscape photography">Cloudscape</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Documentary_photography" title="Documentary photography">Documentary</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Eclipse_photography" title="Eclipse photography">Eclipse</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Visual_anthropology" title="Visual anthropology">Ethnographic</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Erotic_photography" title="Erotic photography">Erotic</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Fashion_photography" title="Fashion photography">Fashion</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Fine-art_photography" title="Fine-art photography">Fine-art</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Fire_photography" title="Fire photography">Fire</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Forensic_photography" title="Forensic photography">Forensic</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Glamour_photography" title="Glamour photography">Glamour</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/High-speed_photography" title="High-speed photography">High-speed</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Landscape_photography" title="Landscape photography">Landscape</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Monochrome_photography" title="Monochrome photography">Monochrome</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Nature_photography" title="Nature photography">Nature</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Neues_Sehen" title="Neues Sehen">Neues Sehen</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Nude_photography" title="Nude photography">Nude</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photojournalism" title="Photojournalism">Photojournalism</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Pictorialism" title="Pictorialism">Pictorialism</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Pornography" title="Pornography">Pornography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Portrait_photography" title="Portrait photography">Portrait</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Post-mortem_photography" title="Post-mortem photography">Post-mortem</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Ruins_photography" title="Ruins photography">Ruins</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Selfie" title="Selfie">Selfie</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Space_selfie" title="Space selfie">space selfie</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Social_documentary_photography" title="Social documentary photography">Social documentary</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Sports_photography" title="Sports photography">Sports</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Still_life_photography" title="Still life photography">Still life</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Stock_photography" title="Stock photography">Stock</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Straight_photography" title="Straight photography">Straight photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Street_photography" title="Street photography">Street</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Toy_camera" title="Toy camera">Toy camera</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Underwater_photography" title="Underwater photography">Underwater</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Vernacular_photography" title="Vernacular photography">Vernacular</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Wedding_photography" title="Wedding photography">Wedding</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Wildlife_photography" title="Wildlife photography">Wildlife</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Techniques</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Afocal_photography" title="Afocal photography">Afocal</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bokeh" title="Bokeh">Bokeh</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Brenizer_method" title="Brenizer method">Brenizer</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Burst_mode_(photography)" title="Burst mode (photography)">Burst mode</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Contre-jour" title="Contre-jour">Contre-jour</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Exposing_to_the_right" title="Exposing to the right">ETTR</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Fill_flash" title="Fill flash">Fill flash</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Fireworks_photography" title="Fireworks photography">Fireworks</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Hand-colouring_of_photographs" title="Hand-colouring of photographs">Hand-colouring</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Harris_shutter" title="Harris shutter">Harris shutter</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/High-speed_photography" title="High-speed photography">High-speed</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Holography" title="Holography">Holography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Infrared_photography" title="Infrared photography">Infrared</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Intentional_camera_movement" title="Intentional camera movement">Intentional camera movement</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Kirlian_photography" title="Kirlian photography">Kirlian</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Kite_aerial_photography" title="Kite aerial photography">Kite aerial</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Lo-fi_photography" title="Lo-fi photography">Lo-fi photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Long-exposure_photography" title="Long-exposure photography">Long-exposure</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Luminogram" title="Luminogram">Luminogram</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Macro_photography" title="Macro photography">Macro</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Mordan%C3%A7age" title="Mordançage">Mordançage</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Multiple_exposure" title="Multiple exposure">Multiple exposure</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Multi-exposure_HDR_capture" title="Multi-exposure HDR capture">Multi-exposure HDR capture</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Night_photography" title="Night photography">Night</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Panning_(camera)" title="Panning (camera)">Panning</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Panoramic_photography" title="Panoramic photography">Panoramic</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photogram" title="Photogram">Photogram</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_print_toning" title="Photographic print toning">Print toning</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Pigeon_photography" title="Pigeon photography">Pigeon photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Redscale" title="Redscale">Redscale</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Rephotography" title="Rephotography">Rephotography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Rollout_photography" title="Rollout photography">Rollout</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Scanography" title="Scanography">Scanography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Schlieren_photography" title="Schlieren photography">Schlieren photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Sabattier_effect" title="Sabattier effect">Sabattier effect</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Slow_motion" title="Slow motion">Slow motion</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Stereoscopy" title="Stereoscopy">Stereoscopy</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Stopping_down" title="Stopping down">Stopping down</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Strip_photography" title="Strip photography">Strip</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Slit-scan_photography" title="Slit-scan photography">Slit-scan</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Sun_printing" title="Sun printing">Sun printing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Tilt%E2%80%93shift_photography" title="Tilt–shift photography">Tilt–shift</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Miniature_faking" title="Miniature faking">Miniature faking</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Time-lapse_photography" title="Time-lapse photography">Time-lapse</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Ultraviolet_photography" title="Ultraviolet photography">Ultraviolet</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Vignetting" title="Vignetting">Vignetting</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Xerox_art" title="Xerox art">Xerography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Zoom_burst" title="Zoom burst">Zoom burst</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Composition_(visual_arts)" title="Composition (visual arts)">Composition</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Diagonal_method" title="Diagonal method">Diagonal method</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Framing_(visual_arts)" title="Framing (visual arts)">Framing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Headroom_(photographic_framing)" title="Headroom (photographic framing)">Headroom</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Lead_room" title="Lead room">Lead room</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Rule_of_thirds" title="Rule of thirds">Rule of thirds</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Simplicity_(photography)" title="Simplicity (photography)">Simplicity</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Golden_triangle_(composition)" title="Golden triangle (composition)">Golden triangle (composition)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/History_of_photography" title="History of photography">History</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Timeline_of_photography_technology" title="Timeline of photography technology">Timeline of photography technology</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Ambrotype" title="Ambrotype">Ambrotype</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Analog_photography" title="Analog photography">Analog photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Autochrome_Lumi%C3%A8re" title="Autochrome Lumière">Autochrome Lumière</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Box_camera" title="Box camera">Box camera</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Calotype" title="Calotype">Calotype</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Camera_obscura" title="Camera obscura">Camera obscura</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Daguerreotype" title="Daguerreotype">Daguerreotype</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Dufaycolor" title="Dufaycolor">Dufaycolor</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Heliography" title="Heliography">Heliography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Lippmann_plate" title="Lippmann plate">Lippmann plate</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Painted_photography_backdrops" title="Painted photography backdrops">Painted photography backdrops</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_and_the_law" title="Photography and the law">Photography and the law</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_plate" title="Photographic plate">Glass plate</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Tintype" title="Tintype">Tintype</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Visual_arts" title="Visual arts">Visual arts</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Regional</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Albania" title="Photography in Albania">Albania</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Bangladesh" title="Photography in Bangladesh">Bangladesh</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Canada" title="Photography in Canada">Canada</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_China" title="Photography in China">China</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Denmark" title="Photography in Denmark">Denmark</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Greece" title="Photography in Greece">Greece</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_India" title="Photography in India">India</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Japan" title="Photography in Japan">Japan</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Korea" title="Photography in Korea">Korea</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Luxembourg" title="Photography in Luxembourg">Luxembourg</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Norway" title="Photography in Norway">Norway</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_the_Philippines" title="Photography in the Philippines">Philippines</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Serbia" title="Photography in Serbia">Serbia</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Slovenia" class="mw-redirect" title="Photography in Slovenia">Slovenia</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Sudan" title="Photography in Sudan">Sudan</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Taiwan" title="Photography in Taiwan">Taiwan</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Turkey" title="Photography in Turkey">Turkey</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Ukraine" title="Photography in Ukraine">Ukraine</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_the_United_States" title="Photography in the United States">United States</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Uzbekistan" title="Photography in Uzbekistan">Uzbekistan</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photography_in_Vietnam" title="Photography in Vietnam">Vietnam</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_photography" title="Digital photography">Digital photography</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_camera" title="Digital camera">Digital camera</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_single-lens_reflex_camera" title="Digital single-lens reflex camera">D-SLR</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Comparison_of_digital_SLRs" title="Comparison of digital SLRs">comparison</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Mirrorless_camera" title="Mirrorless camera">MILC</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_camera_back" title="Digital camera back">camera back</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digiscoping" title="Digiscoping">Digiscoping</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Comparison_of_digital_and_film_photography" title="Comparison of digital and film photography">Comparison of digital and film photography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Film_scanner" title="Film scanner">Film scanner</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Image_sensor" title="Image sensor">Image sensor</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Active-pixel_sensor" title="Active-pixel sensor">CMOS APS</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Charge-coupled_device" title="Charge-coupled device">CCD</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Three-CCD_camera" title="Three-CCD camera">Three-CCD camera</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Foveon_X3_sensor" title="Foveon X3 sensor">Foveon X3 sensor</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Image_sharing" title="Image sharing">Image sharing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Pixel" title="Pixel">Pixel</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Color_photography" title="Color photography">Color photography</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Color_print_film" title="Color print film">Print film</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Chromogenic_print" title="Chromogenic print">Chromogenic print</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Reversal_film" title="Reversal film">Reversal film</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Color_management" title="Color management">Color management</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Color_space" title="Color space">color space</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Primary_color" title="Primary color">primary color</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/CMYK_color_model" title="CMYK color model">CMYK color model</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/RGB_color_model" title="RGB color model">RGB color model</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_processing" title="Photographic processing">Photographic<br/>processing</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Bleach_bypass" title="Bleach bypass">Bleach bypass</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/C-41_process" title="C-41 process">C-41 process</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Collodion_process" title="Collodion process">Collodion process</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Cross_processing" title="Cross processing">Cross processing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Cyanotype" title="Cyanotype">Cyanotype</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_developer" title="Photographic developer">Developer</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Digital_image_processing" title="Digital image processing">Digital image processing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Dye_coupler" title="Dye coupler">Dye coupler</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/E-6_process" title="E-6 process">E-6 process</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Photographic_fixer" title="Photographic fixer">Fixer</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Gelatin_silver_process" class="mw-redirect" title="Gelatin silver process">Gelatin silver process</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Gum_printing" title="Gum printing">Gum printing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Instant_film" title="Instant film">Instant film</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/K-14_process" title="K-14 process">K-14 process</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Print_permanence" title="Print permanence">Print permanence</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Push_processing" title="Push processing">Push processing</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Stop_bath" title="Stop bath">Stop bath</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Lists</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_largest_photographs" title="List of largest photographs">Largest photographs</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_most_expensive_photographs" title="List of most expensive photographs">Most expensive photographs</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_museums_devoted_to_one_photographer" title="List of museums devoted to one photographer">Museums devoted to one photographer</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_photographs_considered_the_most_important" title="List of photographs considered the most important">Photographs considered the most important</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_photographers" title="List of photographers">Photographers</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_Norwegian_photographers" title="List of Norwegian photographers">Norwegian</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_Polish_photographers" title="List of Polish photographers">Polish</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_street_photographers" title="List of street photographers">street</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_women_photographers" title="List of women photographers">women</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/List_of_photography_periodicals" title="List of photography periodicals">Photography periodicals</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Conservation_and_restoration_of_photographs" title="Conservation and restoration of photographs">Conservation and restoration of photographs</a> <ul><li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Conservation_and_restoration_of_film" title="Conservation and restoration of film">film</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Conservation_and_restoration_of_photographic_plates" title="Conservation and restoration of photographic plates">photographic plates</a></li></ul></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Toy_camera#Lomography" title="Toy camera">Lomography</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Polaroid_art" title="Polaroid art">Polaroid art</a></li> <li><a href="/web/20241116184711/https://en.wikipedia.org/wiki/Stereoscopy" title="Stereoscopy">Stereoscopy</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185"/></span></span> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Category:Photography" title="Category:Photography">Category</a></li> <li><span class="noviewer" typeof="mw:File"><span title="Outline"><img alt="" src="//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/thumb/4/41/Global_thinking.svg/10px-Global_thinking.svg.png" decoding="async" width="10" height="16" class="mw-file-element" srcset="//web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/thumb/4/41/Global_thinking.svg/15px-Global_thinking.svg.png 1.5x, //web.archive.org/web/20241116184711im_/https://upload.wikimedia.org/wikipedia/commons/thumb/4/41/Global_thinking.svg/21px-Global_thinking.svg.png 2x" data-file-width="130" data-file-height="200"/></span></span> <a href="/web/20241116184711/https://en.wikipedia.org/wiki/Outline_of_photography" title="Outline of photography">Outline</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img 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