View source for Infrared photography

{{Short description|Near-infrared imaging}}
{{Use dmy dates|date=March 2023}}
{{Use American English|date=March 2023}}
{{More sources needed|date=October 2025}}
[[File:Tree example IR.jpg|thumb|A tree photographed using the near [[infrared]] range]]
{{Alternative photography}}
In '''infrared photography''', the [[photographic film]] or [[image sensor]] used is sensitive to [[infrared]] light. The part of the [[visible spectrum|spectrum]] used is referred to as near-infrared to distinguish it from far-infrared, which is the domain of [[thermal imaging]]. [[Wavelength]]s used for [[photography]] range from about 700&nbsp;[[nanometre|nm]] to about 900&nbsp;nm. Film is usually sensitive to [[visible light]] too, so an infrared-passing filter is used; this lets infrared (IR) light pass through to the camera, but blocks all or most of the visible light spectrum. These filters thus look black (opaque) or deep red.{{efn|The term "infrared filter" can be used to refer two types of filters: either a ''high-pass filter'' for infrared photography which blocks wavelengths of light lower than a certain value, allowing infrared to pass, or a ''low-pass filter'' that blocks infrared and higher wavelengths but passes visible wavelengths. To distinguish the two types, the low-pass filter is sometimes called a [[hot mirror]] instead.}}

When these [[band-pass filter|filters]] are used together with infrared-sensitive film or sensors, "[[in-camera effect]]s" can be obtained, [[false-color]] or [[black-and-white]] images with a dreamlike or sometimes lurid appearance known as the '''Wood effect''', an effect mainly caused by foliage (such as tree leaves and grass) strongly reflecting infrared in the same way visible light is reflected from snow.{{efn|The Wood effect results from the transparency of chlorophyll at wavelengths over 500&nbsp;nm, allowing light to be reflected within the plant cells. Normally the effect is invisible because so much green light is reflected by the foliage, but it is possible to see the effect, albeit dimly, with the naked eye by looking through a 720&nbsp;nm filter (or similar) on a sunny day and allowing your eye to adjust to the low light.}} There is a small contribution from chlorophyll [[fluorescence]], but this is marginal and is not the real cause of the brightness seen in infrared photographs. The effect is named after the infrared photography pioneer [[Robert W. Wood]], and not after the material wood, which does not strongly reflect infrared.

The other attributes of infrared photographs include very dark skies and penetration of atmospheric haze, caused by reduced [[Rayleigh scattering]] and [[Mie scattering]], respectively, compared to visible light. The dark skies, in turn, result in less infrared light in shadows and dark reflections of those skies from water, and clouds will stand out strongly. These wavelengths also penetrate a few millimeters into skin and give a milky look to portraits, although eyes often look black.

==History==
<gallery heights=150px widths=200px caption="Infrared imaging examples">
File:Tree example VIS.jpg|For comparison, the same tree photographed using the [[Visible spectrum|visible part of the spectrum]]
File:Minnesota Lock and Dam 1 006-062-02-1994.jpg|False-color infrared image of the [[Mississippi River]] crossed by a bridge and a dam, between red foliage on left, and blue parking lots and buildings on right
File:Visible Spectrum vs IR.jpg|Visible and infrared (900 nm LP) aerial photography of [[Old Hickory Lake]], [[Tennessee]]. Taken from a passenger airplane within seconds apart using a [[Sony]] H-9 Digital camera.
File:Bnb train 2 bnw.jpg|A near-infrared photograph of a [[Ringling Bros. and Barnum & Bailey Circus|Ringling Brothers]]' circus train idling near [[Massachusetts Institute of Technology|MIT]] in [[Cambridge, Massachusetts]]
</gallery>
Until the early 20th century, infrared photography was not possible because [[silver halide]] emulsions are not sensitive to longer wavelengths than that of blue light (and to a lesser extent, green light) without the addition of a dye to act as a color sensitizer.<ref>{{cite web
| url = http://www.cheresources.com/photochem.shtml
| title = Chemistry of Photography
| access-date = 2006-11-28
}}</ref> The first infrared photographs (as distinct from spectrographs) to be published appeared in the February 1910 edition of ''[[The Century Magazine]]'' and in the October 1910 edition of the ''[[Royal Photographic Society]] Journal'' to illustrate papers by [[Robert W. Wood]], who discovered the unusual effects that now bear his name.<ref>
{{cite journal
 | journal = The Century Magazine
 | title = A New Departure in Photography
 | author = Robert W. Wood
 | volume = 79
 | issue = 4
 | publisher = The Century Company
 | pages = 565–572
 |date=February 1910}}</ref><ref>
{{cite journal
 | journal = The Photographic Journal
 | title = Photography By Invisible Rays
 | author = Robert W. Wood
 | volume = 50
 | issue = 10
 | publisher = Royal Photographic Society
 | pages = 329–338
 |date=October 1910}}</ref><ref>
{{cite web
 | url = http://msp.rmit.edu.au/Article_04/06.html
 | title = Pioneers of Invisible Radiation Photography – Professor Robert Williams Wood
 | access-date = 2006-11-28
|archive-url = https://web.archive.org/web/20061112155531/http://msp.rmit.edu.au/Article_04/06.html <!-- Bot retrieved archive --> |archive-date = 2006-11-12}}</ref>
The RPS co-ordinated events to celebrate the centenary of this event in 2010.<ref>
{{cite journal
 | journal = The RPS Journal
 | title = 100 Years of Infrared
 | volume = 148
 | issue = 10
 | publisher = Royal Photographic Society
 | pages = 571
 | date = Dec 2008 – Jan 2009
 }}</ref> Wood's photographs were taken on experimental film that required very long exposures; thus, most of his work focused on landscapes. A further set of infrared landscapes taken by Wood in Italy in 1911 used plates provided for him by [[Kenneth Mees|C. E. K. Mees]] at [[Frederick Wratten|Wratten]] & Wainwright. Mees also took a few infrared photographs in Portugal in 1910, which are now in the Kodak archives.{{cn|date=October 2025}}

Infrared-sensitive photographic plates were developed in the United States during [[World War I]] for spectroscopic analysis, and infrared sensitizing dyes were investigated for improved haze penetration in aerial photography.<ref>{{cite book |url=https://books.google.com/books?id=Y1GLcdK98HwC&pg=PA114 |title=Annual Report of the Director Bureau of Standards to the Secretary of Commerce for the Fiscal Year Ended June 30, 1919 |publisher=United States Government Printing Office, United States National Bureau of Standards |pages=115–119 |date=1919}}</ref>  After 1930, new emulsions from Kodak and other manufacturers became useful to [[infrared astronomy]].<ref>{{cite journal |url=http://adsabs.harvard.edu/full/1934ApJ....79..183M |title=Photogeara0phy of the Near Infra-Red Region of Stellar Spectra |first=Paul W. |last=Merrill |journal=Astrophysical Journal |date=1934 |volume=79 |pages=183–202|doi=10.1086/143528 |bibcode=1934ApJ....79..183M }}</ref>

[[File:Are You Experienced - US cover-edit.jpg|thumb|left|[[Album cover]] of ''[[Are You Experienced]]'' (1967) by [[The Jimi Hendrix Experience]]; the photographer captured the trio with a [[fisheye lens]] on color infrared film]]
Infrared photography became popular with photography enthusiasts in the 1930s, when suitable film was introduced commercially. ''The Times'' regularly published landscape and aerial photographs taken by their staff photographers using [[Ilford Photo|Ilford]] infrared film. By 1937, 33 kinds of infrared film were available from five manufacturers including [[Agfa]], [[Kodak]] and Ilford.<ref>
{{cite book
 | title = Photography by infrared: its Principles and Applications
 | author = Walter Clark
 | publisher =  Wiley
 | year = 1939
 | url =https://archive.org/details/photographybyinf0000clar
 | url-access = registration
 }}</ref>
Infrared movie film was also available and was used to create [[Day for night|day-for-night]] effects in motion pictures. A notable example being the pseudo-night aerial sequences in the movie ''[[The Bride Came C.O.D.]]'', starring James Cagney and Bette Davis.<ref>American Cinematographer 1941 Vol 22</ref>

False-color infrared photography became widely practiced with the introduction of Kodak Ektachrome Infrared Aero Film and Ektachrome Infrared EIR. The first version of this, known as Kodacolor Aero-Reversal-Film, was developed by Clark and others at the Kodak for camouflage detection in the 1940s. The EIR film became more widely available in the form of [[135 film|35 mm film]] in the 1960s but has been since discontinued.

Infrared photography became popular with a number of 1960s recording artists, because of the unusual results; [[Jimi Hendrix]], [[Donovan]], [[Frank Zappa]] and the [[Grateful Dead]] all issued albums with infrared cover photos. The unexpected colors and effects that infrared film can produce fit well with the [[Psychedelic art|psychedelic]] aesthetic emerging in the 1960s.{{Citation needed|date=December 2018}}

==Techniques and special equipment==

===Infrared filters===
[[File:IR filters 01 Pengo.jpg|thumb|Infrared-passing filters]]
Infrared light lies between the visible and microwave portions of the [[electromagnetic spectrum]]. Infrared light has a range of wavelengths, just like visible light has wavelengths that range from red light to violet. "Near infrared" light is closest in wavelength to visible light, ranging from approximately 700 to 5000&nbsp;nm, and "far infrared" is closer to the microwave region of the electromagnetic [[spectrum]], ranging from approximately 25 to 350&nbsp;[[micron|μm]].<ref>{{cite web |url=https://www.icc.dur.ac.uk/~tt/Lectures/Galaxies/Images/Infrared/Regions/irregions.html |title=Near, Mid & Far Infrared |website=Infrared Processing and Analysis Center |access-date=23 August 2024}}</ref> The longer, far infrared wavelengths are about the size of a pinhead and the shorter, near infrared ones are the size of cells, or are microscopic.

Historically, black-and-white infrared films are sensitive to near infrared wavelengths shorter than approximately 860&nbsp;nm, and retain significant sensitivity to blue wavelengths.<ref>{{cite book |url=https://archive.org/details/infrared-ultraviolet-photography |title=Infrared and Ultraviolet Photography |publisher=Eastman Kodak |date=1947 |edition=Second |access-date=23 August 2024}}</ref>{{rp|3;5;21}}<ref name=White95>{{cite book |url=https://archive.org/details/infraredphotogra0000whit/page/16/mode/2up |title=Infrared photography handbook |first=Laurie |last=White |date=1995 |page=17 |publisher=Amherst Media Inc. |location=Buffalo, New York |isbn=0-936262-38-9 |lccn=95-79716 |access-date=23 August 2024 |url-access=registration}}</ref> Infrared-passing filters are used in black-and-white infrared photography to block blue wavelengths and limit the photograph to infrared wavelengths only. Without filters, infrared negative films look much like conventional negative films because the blue sensitivity lowers the contrast and effectively counteracts the infrared look of the film.<ref>{{cite magazine |url=https://books.google.com/books?id=gV4zAQAAMAAJ&pg=PA72 |title=Infrared Film for special effects |first=Lloyd |last=West |date=June 1956 |magazine=Popular Photography |pages=72;122 |access-date=28 August 2024}}</ref><ref name=Clark39>{{cite book |url=https://archive.org/details/photographybyinf0000clar/ |title=Photography by Infrared: its principles and applications |first=Walter |last=Clark |date=1939 |publisher=John Wiley & Sons, Inc. |location=New York, New York |url-access=registration |quote=Infrared plates and films are sensitive to the ultraviolet, violet and blue, as well as to the infrared. Their response to the short wavelengths is so much higher than that to the infrared that it is necessary to use some means for confining the exposures to the infrared. Otherwise, the photographs will appear just like normal negatives.}}</ref>{{rp|16}} Typically, a red filter ([[Wratten number|Wratten]] #25) is recommended as the best compromise, which removes blue wavelengths while still passing enough visible light for focusing.<ref name=White95/><ref name=Clark39/>{{rp|16}}

{|class="wikitable floatright" style="font-size:80%;text-align:center;width:5em;"
|+Wratten IR filter nos.<ref>{{cite web |url=https://pe2bz.philpem.me.uk/Lights/-%20Filters/WrattenFilters-IR+UV/irfilter.htm |first=Willem-Jan |last=Markerink |date=2002 |title=Wratten filters for Infrared- & UV-Photography |access-date=21 August 2024}}</ref><ref name=Kodak70>{{cite book |url=https://archive.org/details/kodakfiltersfors00koda/ |title=Kodak filters for scientific and technical uses |date=1970 |publisher=Eastman Kodak Company |isbn=0-87985-029-9}}</ref>{{rp|35;64–66;81}}
! [[Wratten number|No.]] !! 50% (nm){{efn|The approximate transition wavelength where the filter achieves 50% transmission; longer wavelengths are passed, while lower wavelengths are absorbed.}}
|-style="background:#f90;"
| 15  || 530
|-style="background:#f20;"
| 21  || 560
|-style="background:#f00;color:#fff;"
| 23A || 580
|-style="background:#d00;color:#fff;"
| 25  || 600
|-style="background:#a00;color:#fff;"
| 29  || 620
|-style="background:#600;color:#fff;"
| 70  || 675
|-style="background:#400;color:#fff;"
| 89B || 720
|-style="background:#200;color:#fff;"
| 88  || 735
|-style="background:#200;color:#fff;"
| 72B || 740
|-style="background:#000;color:#fff;"
| 88A || 750
|-style="background:#000;color:#fff;"
| 87  || 795
|-style="background:#000;color:#fff;"
| 87C || 850
|-style="background:#000;color:#fff;"
| 87B || 930
|-style="background:#000;color:#fff;"
| 87A || 1050
|}
Some photographers use orange or red filters to allow slight amounts of blue wavelengths to reach the film, and thus lower the contrast. The majority of black-and-white infrared art, landscape, and [[wedding photography]] is done using orange (Wratten #15 or 21), red (#23, 25, or 29) or visually opaque (#72){{efn|In addition to its high-pass spectral characteristics, Wratten #72B has an additional transmission notch, peaking at approximately 10% in the red-orange band, centered on 600&nbsp;nm.<ref name=Kodak70/>{{rp|81}}}} filters over the lens to block the blue visible light from the exposure. Very dark-red (#29) filters block out almost all blue, and visually opaque (#70, 89b, 87c, 72) filters block out all blue and also visible red wavelengths, resulting in a more pure-infrared photo with a more pronounced contrast.

Instead of the Wratten number, some manufacturers embed the transition or cutoff wavelength in the name of the filter. For example, Hoya markets the R72 (720&nbsp;nm cutoff, 750&nbsp;nm 50% transition)<ref>{{cite web |url=https://hoyafilter.com/product/r72_infrared/ |title=Hoya R72 Infrared |website=Hoya Filter |access-date=23 August 2024}}</ref> and RM90 (900&nbsp;nm cutoff) filters for infrared photography.<ref>{{cite web |url=https://archive.org/details/manualzilla-id-7167041/page/52/mode/2up |title=Hoya Filter Catalog |lang=de |publisher=Hoya |access-date=23 July 2024 |page=52}}</ref> B+W ([[Schneider Kreuznach]]) and Heliopan sell filters using glass sourced from [[Schott AG]], including types RG695 (695&nbsp;nm transition, considered approximately equivalent to Wratten #89B), RG715 (715&nbsp;nm, #88A), RG780 (780&nbsp;nm, #87), RG830, RG850, and RG1000.<ref>{{cite web |url=http://www.heliopan.de:80/Heliopan-Filters.pdf |archive-url=https://web.archive.org/web/20070103034209/http://www.heliopan.de:80/Heliopan-Filters.pdf |title=Filters for Digital Photography |publisher=Heliopan |archive-date=January 3, 2007 |url-status=dead}}</ref><ref>{{cite web |url=https://cdn.manfrotto.com/media/downloadable/manual/Brochure-B+W_EN.pdf |title=75 Years Filter Fascination |date=July 2022 |publisher=B+W Filter, Jos. Schneider Optische Werke GmbH |access-date=27 August 2024}}</ref>{{rp|26;38}}

===Focusing infrared===
[[File:AiS Nikkor 85mm-2.0 (3116699202).jpg|thumb|left|Nikon lens for [[Nikon F mount]]; the infrared index mark is the small red dot under one yellow hash mark for hyperfocal range at {{f/|8}}.]]
Many [[manual focus]] lenses for 35&nbsp;mm [[single-lens reflex camera]]s (SLR) and [[medium format (film)|medium format]] SLR have a red dot, line or diamond, often with a red "R" called the infrared index mark, which can be used to achieve proper infrared focus; many autofocus lenses no longer have this mark. For these lenses, after visual focus is achieved for the intended subject, the distance indicated by the visual focusing mark is then re-set to the infrared index mark.<ref>{{cite book |chapter-url=https://archive.org/details/nikonnikkormatha0000jose/page/n213/mode/2up |title=Nikon-Nikkormat Handbook of Photography |chapter=4 |first=Joseph David |last=Cooper |date=1974 |publisher=American Photographic Book Publishing Company, Inc. |location=Garden City, New York |isbn=0-8174-0566-6 |page=4-25 |chapter-url-access=registration}}</ref> Without refocusing, a sharp infrared photograph can be taken by proper hyperfocal settings, which generally requires a tripod, a narrow aperture (like {{f/|8}});{{Citation needed|date=August 2010}} however, wider apertures like {{f/|2.0}} can produce sharp photos when the lens is meticulously refocused to the infrared index mark, and only if this index mark is the correct one for the filter and film in use. [[Airy disk|Diffraction]] effects inside a camera are greater at infrared wavelengths so that stopping down the lens too far may actually reduce sharpness.

Some lens manufacturers such as [[Leica Camera|Leica]] never put IR index marks on their lenses. The reason for this is that any index mark is only valid for one particular IR filter and film combination, and may lead to user error. Even when using lenses with index marks, focus testing is advisable as there may be a large difference between the index mark and the [[subject plane]].

Most [[apochromat]]ic ('APO') lenses do not have an Infrared index mark and do not need to be refocused for the [[Infrared spectroscopy|infrared spectrum]] because they are already optically corrected into the near-infrared spectrum. [[Catadioptric]] lenses do not often require this adjustment because their [[mirror]] containing elements do not suffer from [[chromatic aberration]] and so the overall aberration is comparably less. [[Catadioptric]] lenses do, of course, still contain lenses, and these lenses do still have a dispersive property.

When a SLR camera is fitted with a filter that is opaque to visible light, the reflex system becomes useless for both framing and focusing, one must compose the picture without the filter and then attach the filter. This requires the use of a tripod to prevent the composition from changing.

[[Zoom lens]]es may scatter more light through their more complicated optical systems than [[prime lens]]es, that is, lenses of fixed focal length; for example, an infrared photo taken with a 50&nbsp;mm prime lens may have more contrast than the same image taken at 50&nbsp;mm with a 28–80 zoom.

==Film cameras==
[[File:fogged hienegs.png|thumb|right|Infrared negatives fogged by the frame counter of a [[Minolta Maxxum 4]]]]

Many conventional cameras can be used for near-infrared photography, where the portion of the infrared is light of a wavelength only slightly longer than that of visible light. Photography of the far-infrared spectrum with longer wavelengths is called [[thermography]] and requires special equipment.

With some patience and ingenuity, most film cameras can be used. However, some cameras of the 1990s that used [[135 film|35 mm film]] have infrared sprocket-hole sensors that can fog infrared film (their manuals may warn against the use of infrared film for this reason). Other film cameras are not completely opaque to infrared light.

Arguably the greatest obstacle to infrared film photography has been the difficulty of obtaining infrared-sensitive film. Kodak typically manufactured just one or two batches of infrared films per year.<ref name=White95/>{{rp|100}}<ref name=Begleiter02>{{cite book |url=https://archive.org/details/artofcolorinfrar0000begl/ |title=The art of color infrared photography |first=Steven H |last=Begleiter |date=2002 |publisher=Amherst Media |isbn=978-1-58428-065-1 |access-date=27 August 2024 |url-access=registration}}</ref>{{rp|25}} In addition, the popularity of digital photography has pushed film manufacturers to discontinue niche film products, including infrared-sensitive films. The discontinuance of Konica Infrared 750 (2006),<ref>{{cite news |url=https://www.wsj.com/articles/SB113767895658950829 |title=Konica to quit cameras, film |first=Kanji |last=Ishibashi |agency=Dow Jones Newswires |date=January 20, 2006 |newspaper=The Wall Street Journal |url-access=subscription |access-date=27 August 2024}}</ref> Kodak High-Speed Infrared (2007),<ref name=KodakPR2007/> and [[Efke]] IR820 Aura (2012) has now narrowed the selection for [[Monochrome photography|black-and-white]] infrared film to Agfa Aviphot films, made for areal photography.<ref>{{cite web |url= https://www.agfa.com/specialty-products/solutions/aerial-photography/aviphot/ |title=Agfa Aviphot film |website=Agfa Specialty Producys |access-date=1 December 2024}}</ref> These films are not available directly to consumers and must be purchased in large quantities and non-consumer formats. This film is often bought by large companies and sold in consumer quantities and formats under different brands, such as Rollei Infrared 400 film.<ref>{{cite web |url=https://www.rolleianalog.com/wp-content/uploads/2021/07/INFRARED_Data-Sheet_EN_R210701.pdf |title=Rollei Infrared Data Sheet |website=Rollei Analog |access-date=27 August 2024}}</ref>

===Black-and-white infrared film===
Black-and-white infrared negative films are sensitive to wavelengths in the 700 to 900&nbsp;nm [[Near infrared spectroscopy|near infrared spectrum]], and most also have an inherent sensitivity to blue light wavelengths.<ref>{{cite book |url=https://archive.org/details/KodakReferenceHandbook/ |title=Kodak Reference Handbook |date=1946 |chapter-url=https://archive.org/details/KodakReferenceHandbook/page/n107/mode/2up |chapter=Kodak Films |publisher=Eastman Kodak Company |location=Rochester, New York |access-date=27 August 2024}}</ref>{{rp|37–38}} [[Kodak High-Speed Infrared]] (HIE), which produced [[Negative (photography)|negative]]s for photographic prints, was one of the most common black-and-white infrared films used. Because HIE was so prevalent, black-and-white infrared photographs have been associated with a notable halation effect or glow often seen in the highlights, similar to the [[soft focus]] effect of uncorrected [[spherical aberration]].<ref name=Harnischmacher-2008/>{{rp|55}} This halation is an artifact of the clear polyester [[film base]] used for HIE and not inherent to infrared photography; it is caused by the absence of an [[Anti-halation backing|anti-halation layer]] on the back side of Kodak HIE film, which results in a scattering or blooming around the highlights that would usually be absorbed by the anti-halation layer in conventional films. In addition, the clear backing means that Kodak HIE must only be loaded and unloaded in total darkness.{{efn|This is because HIE lacks anti-halation layers and has a completely transparent base rather than being directly due to infrared sensitivity. Film usually has a slightly fogged base and anti-halation layers coated on it in order to stop light reflections in the substrate while the film is being exposed. Light can enter film through the tail protruding from a 35mm canister and without a fogged base it will be [[Light pipe|piped]] into the film and expose it. Without an anti-halation layer, any light entering the substrate through the emulsion will be reflected back and forth inside the film, becoming diffuse as it travels and causing halation. HIE lacked a fogged base and anti-halation layers for two reasons: sensitivity is increased by allowing light to reflect back and forth and it was difficult to find any way of treating the film that would be effective at infrared wavelengths.}}<ref name=Kodak-F13/>

[[File:Rudin-house.jpg|thumb|upright=2.5|[[Frank Lloyd Wright]]'s [[Walter Rudin House|Rudin House]]: panchromatic film on the left, infrared on the right]]

Infrared black-and-white films require special development times but exposed film can be processed using standard black-and-white [[photographic developer]]s and chemicals, including D-76;<ref name=Kodak-F13/>{{rp|4}} the choice of chemical may affect the characteristic exposure/density curve.<ref name=White95/>{{rp|44–47}} Kodak HIE film has a [[polyester]] film base that is very stable but extremely easy to scratch, therefore special care must be used in the handling of Kodak HIE throughout the development and printing/scanning process to avoid damage to the film.

Kodak HIE was sensitive to 900&nbsp;nm. Other infrared black-and-white films include:
* [[Agfa-Gevaert|Agfa]] Aviphot (sensitive to approximately 770&nbsp;nm) Widely available in most formats, such as [[135 film]], [[120 film]], and sheets by larger resellers (such as [https://www.rolleifilm.com/ Rollei] as 80S, 400S and IR 400) and individuals. Occasionally [[220 film]], 70mm film, and other formats not sold at scale may be available from individual sellers.<ref>{{cite web |url=https://www.agfa.com/specialty-products/wp-content/uploads/sites/8/2017/06/AVIPHOT-PAN-200.pdf |title=Aviphot Pan 200 data sheet |date=January 2009 |publisher=Agfa-Gevaert N.V. |access-date=27 August 2024}}</ref>
* Fotokemika/Efke IR 820 (also sensitive to approximately 800&nbsp;nm)<ref>{{cite web |url=https://www.shutterbug.com/content/efke%E2%80%99s-ir-820-infrared-film-unique-ir-option |title=Efke's IR 820 Infrared Film |first=Roger W. |last=Hicks |date=February 1, 2008 |website=Shutterbug |access-date=27 August 2024}}</ref>
* [[Ilford Photo|Ilford]] SFX 200 ("extended" sensitivity in the near-infrared range to 740&nbsp;nm)<ref>{{cite web |url=https://www.ilfordphoto.com/amfile/file/download/file/1907/product/701/ |title=SFX 200 Technical Information |date=November 2018 |publisher=Ilford Photo, Harman Technology Limited |access-date=27 August 2024}}</ref>
* Konica Infrared 750 (sensitive to approximately 800&nbsp;nm)<ref>{{cite web |url=https://125px.com/docs/film/konica/INF750.pdf |title=Konica Infrared 750 Data Sheet |publisher=Konica |access-date=27 August 2024}}</ref>
{{Clear}}

===Color infrared film===
[[File:Kodak Ektachrome IE 135-20 Infrared Slide Film.jpg|thumb|Kodak Ektachrome Infrared Color 35mm Color Film (expired in the 1970s)]]
Like HIE, the most commonly used infrared color [[reversal film]], also called transparency or slide film, was manufactured by Kodak and sold as Ektachrome Infrared (EIR), under code 2236, packaged as a 36-exposure roll; in addition, Kodak made EIR in bulk lengths (for the motion picture industry) and the similar Aerochrome III Infrared for aerial photography (codes 1443 and SO-734).<ref name=Begleiter02/>{{rp|19}} EIR originally was developed during World War II as a means to detect camouflaged objects, taking advantage of the difference in infrared reflectance between plants and green paint,<ref>{{cite patent |country=US |status=Patent |number=2403722A |title=Camouflage detection |assign=Eastman Kodak Co |invent1=Jelley, Edwin E. |invent2=Wilder, Lot S. |pubdate=July 9, 1946 |fdate=October 24, 1942}}</ref> and was adopted by the military and scientific communities after the war. It was not marketed to consumers until the 1960s.<ref name=Begleiter02/>{{rp|12–13}} To improve camouflage paint, companies began incorporating infrared-reflecting materials.<ref>{{cite magazine |url=https://books.google.com/books?id=WNYDAAAAMBAJ&pg=RA1-PA82 |title=Playing Hide and Seek for Keeps |magazine=Popular Mechanics |date=March 1943 |pages=82–87 |access-date=27 August 2024 |quote=Not even infrared film, used as an X-ray for piercing man-made camouflage, will always reveal a war factory that is disguised in the new way. Special infrared paints have been developed in many shades and are being used to fool that type of film. [...] Most paints absorb infrared or heat rays, and even black paint appears white when photographed with infrared film and a red filter. The secret of the infrared paints is that they reflect the heat rays instead of absorbing them, thus providing dark images in infrared film.}}</ref>

{{multiple image |align=right |direction=vertical |title=Color [[reversal film]]
 |image1=E-6 step 01.svg |caption1=During exposure, light selectively sensitizes each of the three wavelength-sensitive layers; an internal blue-blocking filter is used to prevent false sensitization of the red- and green-sensitive layers
 |image2=E-6 step 05.svg |caption2=After [[E-6 process|E-6 development process]], with [[subtractive color]] negative layers}}
The structure of all color reversal films (both standard and infrared-sensitive) contains at least three separate [[densitometry|photosensitive]] layers. Each layer is specifically sensitized to respond to a different set of wavelengths; for instance, a standard color reversal film has red-, green-, and blue-sensitive layers.<ref name=Z119-1>{{cite web |url=http://www.kodak.com/global/plugins/acrobat/en/service/Zmanuals/z119-1.pdf |title=Process E-6 Using KODAK Chemicals, Process E-6 Publication Z-119 {{!}} Chapter 1: Processing solutions and their effects |publisher=[[Kodak]] |archive-url=https://web.archive.org/web/20050825145808/http://kodak.com/global/plugins/acrobat/en/service/Zmanuals/z119-1.pdf |archive-date=August 25, 2005 |url-status=dead}}</ref> During the modern [[E-6 process]] of development, grains of [[silver halide]] that were sensitized by the appropriate wavelengths of light in each layer react with a [[redox|reducing]] agent to form metallic silver particles. The unexposed grains are then sensitized chemically during a second development step and produce oxidized developer, which react with [[dye coupler]] compounds embedded in the film [[emulsion]] layers to form negative images in various color [[dye]]s, respective to how the silver halide was originally sensitized for each layer.{{cn|date=October 2025}}

In conventional color films, the topmost (blue-sensitive) layer gets exposed to light prior to the green- and red-sensitive layers stacked behind it. Since the green- and red-sensitive layers also retain an inherent sensitivity to blue light, a yellow filter layer is placed behind the blue-sensitive layer, in front of the green and red-sensitive layers. This serves to minimize undesired passthrough of shorter wavelengths that are not supposed to expose the bottom layers.{{cn|date=October 2025}}

During development, each emulsion layer forms a negative image in the appropriate [[subtractive color]] (cyan-magenta-yellow): the blue-sensitive layer forms a yellow-dyed ("minus-blue") negative image, the green-sensitive layer forms a magenta-dyed negative image, and the red-sensitive layer forms a cyan-dyed negative image. When the slide is viewed or projected by passing white light through these stacked layers, the visible wavelengths are filtered correspondingly with the reversed colors. For example, blue light will result in no yellow dye formation in the blue-sensitive layer, but cyan and magenta dye will form in the red- and green-sensitive layers. By projecting white light through the combined layers, blue is produced: cyan (aka negative-red) removes red and passes blue and green, and magenta (aka negative-green) removes green and passes blue and red; when these layers are stacked, only blue light is passed.{{cn|date=October 2025}}

Since silver halides are sensitive to wavelengths of light outside of the visible range of the [[electromagnetic spectrum]], longer wavelengths corresponding with infrared light can be captured by using suitable dyes. Without specialized dyes, silver halides are only sensitive to a wavelength shorter than around 450&nbsp;nm.<ref>{{cite book | last=Fujita | first=Shinsaku | chapter=Spectral Sensitization and Sensitizing Dyes | date=2004 | title=Organic Chemistry of Photography | chapter-url=https://doi.org/10.1007/978-3-662-09130-2_7 | publisher=Springer | pages=113–134 | doi=10.1007/978-3-662-09130-2_7| isbn=978-3-642-05902-5 }}</ref>
{{clear}}
{|class="wikitable" style="font-size:100%;text-align:center;"
|+Comparison of color [[reversal film]] structure ([[E-6 process]])
! colspan=3 | Conventional<ref name=Z119-1/>
| rowspan=7 | &nbsp;
! colspan=4 | Infrared<ref name=Kodak-ti-2323/>
|-
! Layer !! Present !! Final dye color
! Final dye color !! Present !! Layer
|-
! style="background:#ffa;" | Yellow filter (external)
| Not used || {{N/A}}
| {{N/A}} || During exposure
! style="background:#ffa;" | Yellow filter (external)
|-
! style="background:#00f;color:#fff;" | Blue-sensitive
| Present || style="background:#ff0;" | Yellow
| style="background:#0ff;" | Cyan || Present
! style="background:#f00;color:#fff;" | IR-sensitive
|-
! style="background:#ffa;" | Yellow filter (internal)
| Present || [[Mathew Carey Lea|Carey Lea silver]], bleached clear
| {{N/A}} || Not present
! style="background:#ffa;" | Yellow filter (internal)
|-
! style="background:#0a0;color:#fff;" | Green-sensitive
| Present || style="background:#f0f;" | Magenta
| style="background:#ff0;" | Yellow || Present
! style="background:#00f;color:#fff;" | Green-sensitive layer
|-
! style="background:#f00;color:#fff;" | Red-sensitive
| Present || style="background:#0ff;" | Cyan
| style="background:#f0f;" | Magenta || Present
! style="background:#0a0;color:#fff;" | Red-sensitive
|}

{{multiple image |align=right |direction=vertical |title=Color infrared [[reversal film]]
 |image1=IR E-6 step 01.svg |caption1=During exposure, light selectively sensitizes each of the three wavelength-sensitive layers; an external blue-blocking filter is used
 |image2=IR E-6 step 05.svg |caption2=After development, with [[false-color]] remapping}}
Color infrared reversal films share a similar three-layer emulsion structure with conventional color reversal films, with the blue-sensitive layer replaced by an infrared-sensitive layer, and different dyes used for each of the layers.<ref name=Kodak-ti-2323>{{cite web |url=http://www.kodak.com/global/en/professional/support/techPubs/ti2323/ti2323.pdf |title=Technical Data / color transparency film: KODAK EKTACHROME Professional Infrared EIR Film [TI-2323] |date=September 2005 |publisher=Eastman Kodak |archive-url=https://web.archive.org/web/20120919162644/http://www.kodak.com/global/en/professional/support/techPubs/ti2323/ti2323.pdf |archive-date=September 19, 2012 |url-status=dead}}</ref> An external yellow [[photographic filter]] is used ([[Wratten number|Wratten]] #12 or equivalent) to block the blue and violet wavelengths, which results in a false-color image by translating or remapping the captured spectrum (from green through infrared) to the visible spectrum: Infrared wavelengths are mapped to the red color, even though the infrared wavelengths are not normally visible. Similarly, visible red wavelengths are remapped to green, and visible green band wavelengths are remapped to blue. The filter and color remapping means visible blue and violet wavelengths are not captured. The infrared-sensitive layer will form cyan dyes (negative-red), while the green-sensitive layer will form yellow dyes (negative-blue) and the red-sensitive layer will form magenta dyes (negative-green).<ref>{{cite book | editor-last1 = Wolfe | editor-first1 = William | editor-last2 = Zissis | editor-first2 = George | date = 1978 | chapter = 14.9 Color Infrared Film | title = The Infrared Handbook | location = Environmental Research Institute of Michigan | publisher = Infrared Information and Analysis Center | pages = 14–16 | lccn = 77-90786}}</ref>

The external yellow filter is used because each emulsion layer in color films (both conventional and infrared) has an inherent sensitivity for short-wavelength radiation (blue and violet visible wavelengths of light) due to the silver halide chemistry. Since there is no blue-sensitive layer, color infrared films also omit the internal yellow filter layer built into conventional color films to protect the following layers. This requires photographers to use an external blue-blocking filter to absorb blue and violet wavelengths of light, which gives the filter a yellow color.{{cn|date=October 2025}}
<gallery heights=150px widths=225px caption="'False-color' (remapped) infrared film examples">
File:Hollywood Hills California.jpg|View of the Hollywood Hills. Kodak Infrared color slide film, no filter used and developed with [[E-6 process]]
File:Color infrared SFOSEAYYZ-tree.jpg|An example of color infrared
File:Dülmen, Lüdinghauser Tor -- 1981 -- 0011.jpg|Lüdinghauser Tor in [[Dülmen]] (1981); remapped false color represents infrared wavelengths (as reflected by foliage) as shades of red
File:Ribeira da Janela Valley on Madeira Island, view from Levada, Infrared False-Color Film (10-79.c).jpg|Ribiera da Janela Valley on [[Madeira Island]], using Kodak EIR (2003)
File:Bluebeard's Castle, St Thomas 1980, Infra Red Film Analog.jpg|Bluebeard's Castle, [[Charlotte Amalie, U.S. Virgin Islands|Charlotte Amalie]] (1980)
</gallery>

Early color infrared films were developed in the older [[E-4 process]], but Kodak later manufactured a color transparency film that could be developed in standard [[E-6 process|E-6]] chemistry, although more accurate results were obtained by developing using the AR-5 process.<ref>{{cite web |url=http://kodak.com/global/en/professional/support/techPubs/cis188/cis188.pdf |title=Current Information Summary: Processing KODAK EKTACHROME Professional Infrared EIR Film |publisher=Eastman Kodak |date=December 2002 |archive-url=https://web.archive.org/web/20061117140048/http://kodak.com/global/en/professional/support/techPubs/cis188/cis188.pdf |archive-date=November 17, 2006 |url-status=dead}}</ref> Like HIE, EIR uses a clear polyester film base and must be loaded in complete darkness. In general, color infrared does not need to be refocused to the infrared index mark on the lens.<ref name=Begleiter02/>{{rp|28}}

Kodak EIR loses its infrared sensitivity as it ages, giving photographs a cyan cast, as fewer grains in the infrared-sensitive (cyan-forming) layer will be sensitized.<ref name=Begleiter02/>{{rp|59}} Anecdotally, EIR is most sensitive up to approximately 21 days after purchase, and stabilizes at a decreased sensitivity thereafter.<ref name=Begleiter02/>{{rp|26}}

===Availability===
Kodak discontinued production of HIE Infrared 35&nbsp;mm film at the end of 2007, stating that, "Demand for these products has been declining significantly in recent years, and it is no longer practical to continue to manufacture given the low volume, the age of the product formulations and the complexity of the processes involved."<ref name=KodakPR2007>{{cite press release |url=http://www.kodak.com/global/en/professional/products/films/discontinuedNotice.jhtml?id=0.2.26.14.25&lc=en |title=Preannounced Professional Film Discontinuances |date=November 2, 2007 |publisher=Kodak |archive-url=https://web.archive.org/web/20071109073342/http://www.kodak.com/global/en/professional/products/films/discontinuedNotice.jhtml?id=0.2.26.14.25&lc=en |archive-date=November 9, 2007 |url-status=dead}}</ref><ref name=Kodak-F13>{{cite web |url=http://www.kodak.com/global/en/professional/support/techPubs/f13/f13.pdf |title=Technical data / black-and-white film: KODAK PROFESSIONAL High-Speed Infrared Film |publisher=Kodak |date=February 2008 |access-date=2016-10-31 |url-status=dead |archive-url=https://web.archive.org/web/20080509094752/http://www.kodak.com/global/en/professional/support/techPubs/f13/f13.pdf |archive-date=2008-05-09 |quote=Due to declining demand, KODAK High-Speed Infrared Film / HIE has been discontinued, effective YE 2007}}</ref> At the time it was discontinued, HIE Infrared 135-36 was available at a street price of around $12.00 a roll at US mail order outlets.

Also in 2007, Kodak announced that production of the 35&nbsp;mm version of their color infrared film (Ektachrome Professional Infrared/EIR) would cease as there was insufficient demand.

In 2008, Los Angeles photographer, Dean Bennici started cutting and hand rolling Aerochrome color Infrared film. Most Aerochrome medium and large format which exists today came directly from his lab. The trend in infrared photography continues to gain momentum with the success of photographer Richard Mosse and multiple users all around the world.<ref>{{Cite web |url=http://www.jotta.com/jotta/article/v3-magazine/2510/saving-film-one-film-stock-at-a-time-dean-bennici |title=Jotta - Article |access-date=2014-11-12 |archive-url=https://web.archive.org/web/20141112211821/http://www.jotta.com/jotta/article/v3-magazine/2510/saving-film-one-film-stock-at-a-time-dean-bennici |archive-date=2014-11-12 |url-status=dead }}</ref>

Since 2011, all formats of color infrared film have been discontinued. Specifically, Aerochrome 1443 and SO-734.{{cn|date=October 2025}}

==Digital cameras==
<gallery heights=150px widths=225px caption="Digital infrared photograph examples">
File:Montreal-in-infrared.jpg|A view in infrared of [[Montréal]] as seen from [[Mont Royal]], taken with filter made of a [[floppy disk]]
File:SD10 IR Bending Tree.jpg|Bending Cypress: infrared shot by [[Sigma SD10]] with B+W 093 filter, ISO 100, {{f/|8}}, 1/160&nbsp;s
File:Succulents in a CT Greenhouse II.jpg|Digital infrared using a 50mm lens, D810 and the program Exposure. Infrared photography typically produces [[false-color]] artifacts, such as turning greens into pinks and purples as shown in this example.
</gallery>
[[Digital camera]] sensors are inherently sensitive to infrared light,<ref>{{cite web|url=http://www.armadale.org.uk/phototech.htm|title=Photographic Techniques|website=www.armadale.org.uk|access-date=3 April 2018|archive-date=11 October 2018|archive-url=https://web.archive.org/web/20181011094302/http://www.armadale.org.uk/phototech.htm|url-status=dead}}</ref> which could interfere with normal photography by confusing the [[autofocus]] calculations, because infrared light wavelengths may focus at a different point than visible light wavelengths, or by softening the image, if the red channel becomes oversaturated. Also, some clothing is transparent in the infrared, leading to unintended (at least to the manufacturer) uses of [[video camera]]s.<ref>{{cite news |url=https://newsroom.ap.org/editorial-photos-videos/detail?itemid=ad99e1a3930185817a1275d284408e3b |title=Japan: Sony Video Camera Turns Out to have X-Ray Vision |date=August 16, 1998 |work=AP News |access-date=26 August 2024}}</ref><ref name="nightshot">{{cite press release
| title = Ultra-Personal Sony Handycam
| publisher = Reuters wire service
| date = 1998-08-12
| access-date = 2007-02-09
| url = http://www.deadmedia.org/notes/38/380.html}}</ref> Thus, to improve image quality and protect privacy, many digital cameras have infrared [[Filter (optics)|blockers]] or [[hot mirror]]s installed in front of their sensors.<ref>{{cite web|url=https://kolarivision.com/articles/internal-cut-filter-transmission/|title=Internal Cut Filter Transmission - Kolari Vision|website=kolarivision.com|date=4 March 2015 |access-date=3 April 2018}}</ref> Depending on the subject matter, adding a infrared-passing filter to the lens may not be practical with these cameras because the exposure times become overly long, often in the range of 30 seconds, creating [[Noise (physics)|noise]] and [[motion blur]] in the final image. However, for some subject matter the long exposure does not matter or the motion blur effects actually add to the image. Some lenses will also show a 'hot spot' in the center of the image as their [[Optical coating|coatings]] are optimized for visible light and not for IR.

There is no currently available digital camera that will directly produce the same results as Kodak color infrared film although equivalent images can be produced using a full spectrum converted infrared digital camera and a Kolari Vision Color IR Chrome lens filter.<ref>{{Cite web|url= https://kolarivision.com/product/kolari-vision-ir-chrome-lens-filter/ |title = Kolari Vision IR Chrome Lens Filter| date=6 February 2019 }}</ref> Similar effects can be achieved by taking two exposures, one infrared and the other full-color, and combining in [[post-production]]. A yellow (minus-blue) filter can also be used, which produces a single image that can also be post-processed to emulate the Ektachrome look.<ref>{{Cite web|url=https://www.infrared100.org/2012/11/emulating-infrared-ektachrome.html|title = Emulating infrared Ektachrome}}</ref> The color images produced by digital still cameras using infrared-pass filters are not equivalent to those produced on color infrared film. The colors result from varying amounts of infrared passing through the color filters on the photo sites, further amended by the Bayer filtering. While this makes such images unsuitable for the kind of applications for which the film was used, such as remote sensing of plant health, the resulting color tonality has proved popular artistically.

Color digital infrared, as part of [[full spectrum photography]] is gaining popularity. The ease of creating a softly colored photo with infrared characteristics has found interest among hobbyists and professionals.

===Hot mirror removal===
[[File:St Lawrence infrared.jpg|thumb|left|An example of color digital infrared photography. The camera's infrared blocking filter has been removed. Red and blue channels have been swapped for more conventional sky color.]]
One method of infrared photography using digital cameras is to remove the infrared blocker in front of the sensor and replace it with a glass cover that either removes or restricts visible light (infrared-only conversion) or one that passes infrared wavelengths ("full spectrum" conversion). This filter is behind the mirror of [[DSLR]]s, so the camera can be used normally - handheld, normal shutter speeds, normal composition through the viewfinder, and focus, all work like a normal camera. Metering works but is not always accurate because of the difference between visible and infrared refraction.<ref>{{cite web|url=http://www.jimchenphoto.com/digitalirfaq.html|title=Digital Infrared at Jim Chen photography|website=www.jimchenphoto.com|access-date=3 April 2018}}</ref> When the IR blocker is removed, many lenses which did display a hotspot cease to do so, and become perfectly usable for infrared photography. Additionally, because the red, green and blue micro-filters remain and have transmissions not only in their respective color but also in the infrared, enhanced infrared color may be recorded.<ref>{{cite web|url=http://surrealcolor.110mb.com/IR_explained_web/IR_explained.htm#IRColor|title=110mb.com - Want to start a website?|website=surrealcolor.110mb.com|access-date=3 April 2018|archive-url=https://web.archive.org/web/20120215235949/http://surrealcolor.110mb.com/IR_explained_web/IR_explained.htm#IRColor|archive-date=15 February 2012|url-status=dead}}</ref>

Since the [[Bayer filter]]s in most digital cameras may also absorb a significant fraction of the infrared light, converted cameras are sometimes not very sensitive to infrared wavelengths and can sometimes produce false colors in the images. An alternative approach is to use a [[Foveon X3 sensor]], which does not have absorptive filters on it; the [[Sigma SD10]] DSLR has a removable IR blocking filter and dust protector, which can be simply omitted or replaced by a deep red or complete visible light blocking filter. The [[Sigma SD14]] has an IR/UV blocking filter that can be removed/installed without tools. The result is a very sensitive digital IR camera.<ref name=Harnischmacher-2008>{{cite book |url=https://archive.org/details/digitalinfraredp0000harn/ |title=Digital Infrared Photography |first=Cyrill |last=Harnischmacher |publisher=Rocky Nook Inc. |location=Santa Barbara, California |date=2008 |isbn=978-1-933952-35-2 |url-access=registration}}</ref>{{rp|32}}

While it is common to use a filter that blocks almost all visible light, the wavelength sensitivity of a digital camera without internal infrared blocking is such that a variety of artistic results can be obtained with more conventional filtration. For example, a very dark neutral density filter can be used (such as the Hoya ND400) which passes a very small amount of visible light compared to the near-infrared it allows through. Wider filtration permits an SLR viewfinder to be used and also passes more varied color information to the sensor without necessarily reducing the Wood effect. Wider filtration is however likely to reduce other infrared artefacts such as haze penetration and darkened skies. This technique mirrors the methods used by infrared film photographers where black-and-white infrared film was often used with a deep red filter rather than a visually opaque one.{{cn|date=October 2025}}

===Post-processing===
Another common technique with near-infrared filters is to swap blue and red channels in software (e.g. [[Adobe Photoshop]]), which retains much of the characteristic "white foliage" while rendering skies a glorious blue.<ref>{{cite web |url=https://lenscraft.co.uk/photo-editing-tutorials/infrared-channel-swap-photoshop/ |title=How To Do An Infrared Channel Swap in Adobe Photoshop |first=Robin |last=Whalley |date=June 9, 2023 |work=Lenscraft Photography |access-date=26 August 2024}}</ref>

[[Phase One (company)|Phase One]] [[digital camera back]]s can be ordered in a modified form suited for infrared photography.

==Applications and specific implementations==
<gallery heights=150px widths=200px caption="Digital infrared applications">
File:Near infra-red kite aerial photo at Rufford Abbey, Nottinghamshire, UK.jpg|An example of the use of infrared photography in aerial archaeology to delineate sub-surface features
File:Series 2009 Five Dollar Bill in Infrared.jpg|The reverse of the [[United States five-dollar bill]] has two rectangular strips that are blanked out when viewed in the infrared spectrum, as seen in this image taken by an infrared camera.
File:Cooktop Ceran IR.JPG|Nightshot infrared photography of a stove with 600 nm red-filter and polarizing filter at daylight
File:Wikipedia Coffee Shot.jpg|Thermographic image of coffee cup
File:IC 10 (infrared, red, green).jpg|The [[starburst galaxy]] [[IC 10]] is hidden behind dust in the [[Milky Way]], but infrared light is less strongly absorbed by dust than visible light. Green patches in the galaxy are its star-forming [[H II region|H II regions]].
</gallery>
The health of foliage can be determined from the relative strengths of green and infrared light reflected using color infrared film; this shows in color infrared as a shift from red (healthy) towards magenta (unhealthy).

Several [[Sony]] cameras had a feature branded as Night Shot, which physically moves the blocking filter away from the light path, making the cameras very sensitive to infrared light. Soon after its development, this facility was 'restricted' by Sony to make it difficult for people to take photos that saw through clothing.<ref name="nightshot"/> To do this the iris is opened fully and exposure duration is limited to long times of more than 1/30 second or so. It is possible to shoot infrared but neutral density filters must be used to reduce the camera's sensitivity and the long exposure times mean that care must be taken to avoid camera-shake artifacts.

[[Fujifilm|Fuji]] have produced digital cameras for use in [[forensic]] criminology and medicine which have no infrared blocking filter. The first camera, designated the S3 PRO UVIR, also had extended [[ultraviolet]] sensitivity (digital sensors are usually less sensitive to UV than to IR). Optimum UV sensitivity requires special lenses, but ordinary lenses usually work well for IR. In 2007, [[Fujifilm|FujiFilm]] introduced a new version of this camera, based on the Nikon D200/ FujiFilm S5 called the [[FinePix IS Pro|IS Pro]], also able to take Nikon lenses. Fuji had earlier introduced a non-SLR infrared camera, the IS-1, a modified version of the FujiFilm [[List of Fujifilm FinePix cameras|FinePix]] S9100. Unlike the S3 PRO UVIR, the IS-1 does not offer UV sensitivity. FujiFilm restricts the sale of these cameras to professional users with their [[EULA]] specifically prohibiting "unethical photographic conduct".<ref>{{cite web|url=http://www.fujifilmusa.com/products/digital_cameras/is/finepix_is1/index.html#Fujifilm|title=IS-1 web page including EULA|website=fujifilmusa.com|access-date=3 April 2018|archive-url=https://web.archive.org/web/20090722031545/http://www.fujifilmusa.com/products/digital_cameras/is/finepix_is1/index.html#Fujifilm|archive-date=22 July 2009|url-status=dead}}</ref>

[[Remote sensing]] and [[thermographic camera]]s are sensitive to longer wavelengths of infrared (see {{section link|Infrared spectrum|Commonly used sub-division scheme}}).  They may be [[multispectral]] and use a variety of technologies which may not resemble common camera or filter designs. Cameras sensitive to longer infrared wavelengths including those used in [[infrared astronomy]] often require cooling to reduce thermally induced dark currents in the sensor (see [[Dark current (physics)]]).  Lower cost uncooled thermographic digital cameras operate in the Long Wave infrared band (see [[Thermographic camera#Uncooled infrared detectors|Thermographic camera]]). These cameras are generally used for building inspection or preventative maintenance but can be used for artistic pursuits as well, such as this image of a cup of coffee.{{cn|date=October 2025}}

==See also==
*{{annotated link|FinePix IS Pro}}
*{{annotated link|Monochrome photography}}
*{{annotated link|Ultraviolet photography}}

== Notes ==
{{notelist}}

== References ==
{{Reflist}}

== External links ==
* {{Commons category-inline}}
* {{cite web |url=https://www.cameraon.ca/infrared-photography-tutorial/ |title=Simple Introduction to Digital Infrared Photography |first=Cameron |last=Penny |date=October 15, 2019 |website=Camera On}}
* {{cite web |url=http://www.naturfotograf.com/UV_IR_rev00.html |title=All you ever wanted to know about digital UV and IR photography, but could not afford to ask |first=Bjørn |last=Rørslett |website=Natur Fotograf}}
* {{cite web |archive-url=https://web.archive.org/web/20080414022905/http://heim.ifi.uio.no/~gisle/photo/ir.html |url=http://heim.ifi.uio.no/~gisle/photo/ir.html |first=Gisle |last=Hannemyr |title=Digital Infrared Resource Page |archive-date=April 14, 2008 |url-status=dead}} List of cameras and their usefulness in digital infrared photography, and lenses that do and don't produce "ir hot-spots"
* {{cite web |url=http://www.kleptography.com/notes-irconvert.htm |title=g-series infrared conversion |first=Tony |last=Kaplan |website=Kleptography}} Conversion instructions for the Canon G1
*[http://vega.org.uk/video/programme/306 Short video showing how to take infrared photographs]
*[https://infra-redmistpete.blogspot.com/2010/01/budget-high-resolution-infra-red.html Make your own budget IR camera]
* {{cite web |url=http://kolarivision.com/problemswithinfrared.html |title=Common problems with infrared photography |first=Ilija |last=Melentijevic|date=March 2, 2015 |website=Kolari Vision}}
* {{cite web |url=https://www.schott.com/shop/advanced-optics/en/Longpass/c/glass-LONGPASS |title=Longpass optical filter glass |publisher=Schott AG}}

{{Photography}}
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{{DEFAULTSORT:Infrared Photography}}
[[Category:Photographic processes]]
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[[Category:Infrared imaging]]