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Infrared (IR) photography - popular myths.

PhotoNotes.org DonationsCopyright © 2001-2014 NK Guy

http://photonotes.org/articles/ir-myths/

Note: most of the information on this page is now totally obsolete, since Kodak has now discontinued their two high-speed infrared films - HIE and EIR. And HIE is the one with all the cool monochrome effects. Other companies make IR-sensitive film, but nothing quite like the classic HIE look. So this page is just a historical footnote now.

When I started looking into film-based infrared photography I found a huge amount of information online. But a lot of it was confusing and offered contradictory advice, which was discouraging. It made shooting IR using film sound really difficult.

But it’s not. So now I’m on my little evangelical quest to explain why shooting infrared film doesn’t have to be the mysterious catastrophe-fraught process that it’s usually made out to be.

I want to correct some of these patently incorrect myths because I know people are wasting all kinds of money and time because of them. It may not be necessary for you to dump your current cameras and lenses in favour of old manual-focus ones, for example.

Note that this document was originally part of an article I wrote on using Canon EOS cameras for shooting IR. I split the myths and the EOS-specific material into two articles, since I felt the myth section was useful to non-EOS users as well. Note that I also don’t discuss the issues associated with using digital cameras for IR photography - that’s a whole other subject unto itself, though some of the myths discussed here are relevant for digital work also.

Table of contents.

10 Easy Steps to shooting IR film.
IR myths and conflicting stories.
Myth: Infrared film records heat.

Myth: EOS cameras fog infrared film because they have plastic bodies.
Myth: Pressure plate cutouts let in infrared energy through from the back.
Myth: Cameras read film-canister DX codes with IR sensors.

Myth: Only Canon cameras fog IR film.
Myth: Some Canon lenses fog infrared film.
Myth: Trees produce infrared energy (or heat), which is why they’re white on HIE film.
Semi-myth: IR film lets you take photographs in the dark.
Myth: You always have to adjust your focus for IR when using a red filter.
Myth: You can’t use autofocus with infrared film.
Myth: Kodak HIE film (“high speed infrared”) is more susceptible to fogging in slow-winding cameras and X-ray machines.
Myth: You can’t use autowinding cameras with infrared film.
Myth: Infrared energy is generated by friction.
Useful Web sites.

10 Easy Steps to shooting IR film.

Before getting started on the myths I thought I’d get this out of the way first: basic IR photography is easy.

Here’s my quick and dirty guide.

  1. Buy a roll of Kodak HIE infrared film as it yields cooler results (usually a glowy, dreamy effect) than the other kinds of black and white IR film. You’ll probably need to go to a professional camera shop or photo lab, as most consumer outfits won’t carry the stuff or even know what it is.

  2. Load the film into your camera in total darkness or as near to it as you can. Do not open the plastic film canister unless you are in total darkness! Be particularly careful not to stick your finger through the camera’s shutter curtain when you’re working in the dark. If you’re outside during the day and can’t find a dark place try going to a shady spot and covering the camera with a leather jacket.

  3. If it’s sunny, set the ISO setting on your camera to 200. If it’s less sunny try setting your camera to ISO 400, but try to shoot under sunnier conditions - the photos will look better as there’s more IR energy than if it’s cloudy. These settings have worked perfectly for me on the three EOS cameras I’ve tried with HIE film - they may require some experimenting on your part if your camera meters light differently.

  4. Stick a red filter on your camera lens. (Wratten red 25, Tamron R2, Hoya 25A, etc.) If you don’t do this you’ll lose a lot of the unique IR look and you’ll end up with a grainy regular black and white photo with glowing highlights. Light-opaque filters which pass IR energy can be used for remarkable IR photos, but are much harder to meter and focus for. I recommend starting with a red filter and moving to an IR filter with experience.

  5. Focus normally. Do not adjust focus for IR, since the red filter lets in a lot of normal light. You only need IR focus compensation if you are using an IR filter that blocks all or most visible light or if you are doing macro (closeup) work, particularly with a large lens aperture.

  6. The picture will hopefully look okay using the camera’s lightmeter. But if there’s a lot of IR energy bouncing around then the camera’s meter will be thrown, so for insurance try shooting one photo at the camera’s recommended exposure settings, then bracket - shoot another photo at 1 stop over the camera’s setting and 1 stop under. If your camera has auto exposure bracketing the easiest way to do this is to set AEB or BKT on your camera to 1 stop.

  7. Take the completed roll out of your camera in total darkness as before. I’d recommend taping the film canister lid shut as a reminder.

  8. Take the roll to a professional lab that specializes in black and white photography, having checked first that they know what to do with infrared film and that it’s something they handle regularly. Get ’em to process and print your film. (okay, so people with their own darkrooms will think this step is cheating since it hands one of the most trouble-prone aspects of IR photography - processing - to someone else. Well, that’s true. But I don’t have my own darkroom and don’t want to spend the money to try and make one.)

  9. Choose the best prints (usually only one shot of the three will really turn out well) and have custom hand-printed enlargements made. Or print up some enlargements yourself if you have access to a darkroom or a rental darkroom facility. Machine-printed black and white prints tend not to be very good.

  10. Show off the photos and bask in the praise and admiration of your friends.

IR myths and conflicting stories.

 There are a lot of myths surrounding infrared photography, probably because IR is a bit of a pain to deal with and the effects are often somewhat unpredictable. I don’t claim to have any firm access to the Truth, but here are some issues I’ve come across. I believe everything I’ve written here is accurate, but welcome corrections and comments using the feedback form at the end of this document.

It’s just part of my attempt to demystify IR, I guess. There’s no particular magic or witchcraft here.


Myth: Infrared film records heat.

This is a common myth - that since heat output is a kind of infrared radiation, then infrared film must detect heat, such as human body heat. This is essentially incorrect.

Explanation: infrared photography is not the same thing as thermal imaging - the night-vision video technology used by the police and sensationalist TV shows. Thermal imaging systems are capable of detecting different wavelengths of IR energy than film.

Infrared film simply records certain wavelengths of infrared radiation emitted by infrared energy sources or, more commonly, reflecting back from objects.

These objects must be illuminated by an IR source - like the sun, a light bulb or a camera flash. Most objects (trees, people, hills, etc) do not radiate IR energy at wavelengths which can be recorded by IR-sensitive film. Film is not sensitive enough to record IR from most heat sources.

In fact, a useful way to think of IR photography is to call it “reflected IR photography,” as a reminder that you’re recording the infrared energy reflected from things (unless you point your camera right at the sun or whatever, of course). The fact that you’re recording reflected IR from the sun is why you can take excellent IR photos on sunny snowy winter days, for example.

If you don’t believe me, try taking a photograph in the dark using IR film. If there are no sources of IR light handy then you’ll get a black picture. (see the related section below)

The one relatively unusual exception that I mention here out of completeness is that of certain kinds of heaters. Electric stove elements can produce a small amount of optically visible infrared energy which can be detected under some circumstances - such as some digital cameras - but most people don’t go around photographing hot stove elements.

I suspect this myth may stem partially from the fact that HIE film is more heat-sensitive in general than regular film. If you don’t keep the film cool it’ll tend to fog up over time. However, the fact that it’s sensitive to heat damage doesn’t mean it’s capable of creating a visual record of heat patterns. You can’t detect heat leaks from poorly insulated houses and you can’t take photos of people’s bodies underneath their clothes or anything like that.

Note also that “infrared light” is technically considered a misnomer by many people, since light is by definition electromagnetic radiation that’s visible to human eyes. However, “infrared light” is a convenient concept, since photographically-detectable IR (from around 700nm to apparently about 1200nm) behaves basically like visible light from a photographic point of view - it can be altered optically and doesn’t behave like gamma radiation or radio waves or anything.

Other people have explained all this better than I have. Check out these links:

http://www.cocam.co.uk/CoCamWS/Infrared/INFRARED.HTM#HEAT

http://www.atsf.co.uk/ilight/tech/thermal.html

http://members.home.net/hmpi/Infrared/Articles/Rethink/rethink.htm

http://www.rit.edu/~andpph/text-infrared-basics.html

Myth: Many cameras fog infrared film because they have plastic bodies.

A common myth and clearly incorrect, as decent plastic-bodied cameras work just fine with infrared film. Obviously, toy cameras which leak light are going to leak IR as well, but that’s not a function of the material - it’s a function of poorly designed and manufactured cameras.

If this myth were true then IR film would fog up if you were to leave your camera sitting around in daylight, which doesn’t happen. Plastic cases are made of pretty thick material and are as opaque to infrared energy as metal is. I think this myth comes from people who have hangups over plastic camera cases and pine for the days of solid metal cameras or something.

I’ve heard similar reports that camera back windows (the ones that let you see the film cartridge) leak infrared energy. This may occasionally happen if the black foam around the window is IR transparent, but I’ve never heard from anyone for whom this has actually been a problem. When in doubt, do some empirical testing, I say. Don’t assume that your camera back window leaks IR until you try it.

Colouring in your camera back window with black felt tip pen, as I’ve heard some people earnestly suggest, clearly won’t do a damn thing as felt tip pen ink on a clear piece of plastic doesn’t even block much regular light. Using heavy black gaffer tape is the only sort of thing that’d likely make much difference if you do actually have a camera back window which leaks light.

Myth: Pressure plate cutouts let in infrared energy through from the back.

Pressure plate cutout holes (used by date-printing camera backs) can indeed cause problems with infrared film. Under certain conditions they can result in dark rectangular or oval shaped fogging of an image. Here’s an example that I took with a Canon EOS Rebel S II camera, which has such a cutout hole in the pressure plate.

However, I’ve heard two conflicting theories as to the cause of the shadowing problem.

The first theory (apparently espoused by an article in EOS Magazine, amongst others) states that there is infrared energy coming through the camera back itself, and this light, though largely blocked by the metal pressure plate, is nonetheless passing through the pressure plate hole and causing the darkening.

This theory is clearly wrong, as it would mean that the camera backs aren’t infrared-opaque (see previous myth). More significantly, the shadowing I’ve noticed has resulted in dark patches on the final print. If the patches were caused by light coming through the hole then the resulting patches would be lighter, not darker, on the final prints.

The second theory is more plausible to me. Most films have a layer of opaque dye on the back, called an anti-halation layer, which essentially absorbs light and prevents light from bouncing around within the film itself. (this layer is washed away during film processing, which is why undeveloped film is opaque but developed film is clear.)

Kodak HIE film lacks this layer. As a result, light passes through the film, exposes some silver halide in the film, then continues through the film to the pressure plate. Some of the light is reflected back off the shiny metal surface of the pressure plate and, since there’s no anti-halation layer, exposes more silver in the film. The result is the characteristic glow (halo) around bright/highlight areas on Kodak HIE photos. Many people like this glowing effect, and it’s definitely a contributing factor to the popularity of the film.

Now, if the pressure plate has a hole in it then light will pass through both the film and the hole, ending up at the camera back itself. The camera back interior is made of matte black plastic and is less reflective than the polished metal pressure plate, so relatively little light is reflected back to the film.

The pressure plate is more reflective than the cutout hole, so as a result the area around the hole looks darker on the final print. This theory seems to predict the observed results correctly, so I’m going with it.

Myth: Cameras read film-canister DX codes with IR sensors.

Another wrong explanation as to why some cameras fog IR film. I’ve never heard of any camera that uses IR energy to read the DX (Camera Auto Sensing Data Exchange codes for ISO film speed, film length and exposure latitude) codes off the sides of film canisters, though I suppose it’s theoretically possible. It’s just that that’d be a strangely complex solution for a simple problem.

Explanation: cameras that can read film-canister DX codes simply have little metal contacts which touch the DX coding area of the metal canister. If a given square is unpainted then the contact touches bare metal, conducting electricity. If the square is painted then it doesn’t conduct electricity. Simple, reliable and a much lower-cost solution than sticking a bunch of light sensors in there.

This erroneous idea may perhaps stem from the fact that there is also barcode information written on the film itself. Unfortunately, this data can’t be used by cameras, because the information printed on the film is encoded in a latent form and is thus not visible until the film is actually developed. The data is only of value to automated printing machines.

Myth: Only Canon cameras fog IR film.

You’ll often hear remarks from people like, “all Nikon cameras work with infrared film but Canons don’t.” This is not correct.

Sadly, it’s true that most current Canon EOS cameras fog high-speed infrared film (Kodak HIE and EIR). However, they aren’t alone. Other camera makers use IR diodes for some of their products, including Nikon (F65/N65 and F80/N80), Contax (Aria, G1, G2), Minolta (Dynax/Maxxum 300si, 500si, XTSi), Hasselblad/Fuji (XPan, but not the XPan II) and Konica (Lexio 70). I’m sure there are many others, but those are just some I’ve heard of.

As with EOS cameras, some of these may fog the image area and some may not - the only way to find out is to test. Many other cameras are afflicted by the pressure plate cutout problem as well. And note that none of Canon’s older (pre EOS/pre-1990 or so) cameras have infrared sensors.

Of course, films which are less sensitive to IR than Kodak’s products are not affected by the EOS infrared diodes, including Konica 750 and Ilford’s SFX.

This page contains a list of which EOS cameras work well with high-speed infrared film and which ones don’t.

http://photonotes.org/articles/eos-ir/

Myth: Some Canon lenses/all autofocus lenses fog infrared film.

I have no clue where this notion comes from. You can use any lens you like for IR photography, though obviously it’d be inconvenient if you found some lens somewhere which lacked a filter mount.

Explanation: I have never heard of any SLR lens which uses any light-producing components for anything, though please correct me if I’m wrong. Canon USM lenses use ultrasonic motors, which produce high-pitched ultrasonic sound. Many Canon camera bodies have a near-IR (but nonetheless visible red) autofocus assist light, but it’s not part of the lens and anyway doesn’t illuminate during the actual picture-taking - it only comes on while you’re focussing. There is nothing about Canon EF lenses (or anybody else’s lenses, for that matter) which can negatively affect IR film in any way.

I suppose in theory it might be possible that some of the antireflective coatings applied to modern camera lenses might conceivably absorb infrared energy, but I’ve never heard of this. This might be confusing things with ultraviolet-sensitive films, which of course are affected by UV-blocking camera filters and coatings.

Now, it’s true that many point and shoot cameras use beams of infrared energy as part of their active autofocus systems. But this doesn’t affect SLRs, since SLRs nearly always use passive autofocus systems rather than active. And even cameras which emit IR during focussing don’t do so when they aren’t focussing. And when they take photos they aren’t focussing.

Myth: Trees produce infrared energy (or heat), which is why they glow white on HIE film.

Another common myth I’ve seen all over the Web. Trees and other plants do not generate any kind of light. As far as I can tell, no known species of plant is naturally bioluminescent - just certain animals, bacteria, plankton and fungi. The only kind of plants which glow are genetically modified Frankenstein plants with firefly luciferase genes spliced into their DNA.

If plants produced light then presumably you could take infrared photos of vegetation at night. But you can’t. And touching any plant quickly reveals that they aren’t great producers of heat either.

Explanation: The reason why deciduous trees, grass, etc., glow white on HIE film is primarily because the structure of their living cells reflects a great deal of the sun’s infrared energy rather than absorbing it. There may also be a secondary effect - a kind of fluorescent effect whereby their cells glow slightly when illuminated by an infrared energy source like the sun.

Either way, this glow is often referred to as the “Wood effect.” It doesn’t refer to wood (which appears dark and not light on IR film) but to R.W. Wood, a pioneer in the field of infrared film. As you can see here, in this photo of an imported statue of Lenin in the Fremont district of Seattle, USA, the Wood effect causes deciduous leaves to glow white with HIE film. And here all along you thought Lenin was simply shining forth with the steadfast power of the proletariat!

Semi-myth: IR film lets you take photographs in the dark.

Well, yes and no. This one probably stems from a bunch of famous photos taken in the 1940s, by a sensationalist New York photographer named “Weegee,” of people watching movies in darkened cinemas. (a classic one is of a naughty couple in a theatre caught making out with their 3D glasses on.)

Explanation: as noted above, infrared film records reflected light and certain frequencies of IR energy. If it’s truly dark then, well, there is no light. So you can’t take photos using infrared film or anything else in total darkness. How, then, were these pictures taken? Very simply - the photographer used a flash with an infrared filter on it. The flash was thus outputting infrared energy that was recorded on the IR film even though it wasn’t visible to the human eye.

So. You can take photos in what appears to be darkness to the human eye, but you still need an infrared energy source of some kind. Taping an IR filter over a flash is one way to do it. (unexposed but developed slide film is a cheap source of IR filtering material) Using an array of IR-emitting diodes is another way - and a method commonly used by security cameras and camcorders that work in the dark.

Myth: You always have to adjust your focus for IR when using a red filter.

You’ve probably read everywhere how difficult it is to focus when using infrared film. Most camera lenses have infrared marks - red dots on the focussing ring that let you compensate for the different wavelength of infrared energy. In other words, visible white light is meant to focus directly on the surface of the film. However, infrared energy, being of different wavelengths, focusses at a different point, resulting in out of focus pictures.

This is all true. However, when you shoot infrared film using a basic red 25 filter there’s still quite a lot of visible light hitting the film. So you usually don’t need to do any IR focus compensation at all when using a plain red filter, particularly if your lens is stopped down for greater depth of field. You only need to mess around with that when using an IR filter that blocks out most visible light (the kind of filters which appear totally black to the human eye) or when shooting close up, particularly with a wide open lens diaphragm.

I think this myth is sort of self-reinforcing. People are told how difficult it is to focus using IR film, adjust focus compensation with a red filter and get out of focus pictures. So they assume they aren’t compensating correctly or the film is hard to focus for, where in fact they simply don’t need to adjust focus at all.

If you don’t believe me, give it a try.

Myth: You can’t use autofocus with infrared film.

This is tied in with the previous myth. If you’re shooting under circumstances under which focus compensation is necessary (eg: closeup photography or when using an infrared filter which is opaque to visible light) then, yes, autofocus is a problem and you should probably switch over to manual focussing. Or autofocus and compensate manually - Canon USM lenses with full-time manual being perfect for this. But for a red 25 filter it’s not usually an issue.

And obviously the fact that a camera has autofocus capabilities does not affect its ability to use HIE film one iota.

Myth: You can’t use autowinding cameras with infrared film.

Another case of confusing the issue. It’s not the motor drive itself that’s the problem - it’s the sprocket hole-counting system used by some motor-driven cameras. There are tons of cameras out there with motor drives which are completely HIE compatible.

A variant of this myth is that cameras which prewind film (wind film all the way into the camera before shooting rather than the reverse) have problems with IR. This is similarly false - the problem involves those prewinding cameras which have IR diodes for counting sprocket holes, as always. Prewinding cameras which use mechanical counters have no problems at all.

Myth: Kodak HIE film (“high speed infrared”) is more susceptible to fogging in slow-winding cameras and X-ray machines.

No. The film is known as “high speed” because it’s fairly sensitive to light - compared to most other types of IR film. But it’s still pretty slow film to react to light - people typically shoot with it at an equivalent ISO rating of ISO 100 or 200. Modern fast film is rated ISO 800 or 1600.

Film winding motor speed is utterly irrelevant. It doesn’t matter if you wind the film slowly by hand with a manual crank-operated camera or if you shoot the film with a power-booster-equipped pro model that blazes along at 10 frames per second. If the camera has internal infrared position-sensing diodes then it will probably fog part of the film. If it doesn’t then it won’t. This myth clearly stems from misunderstanding what “high speed” means here.

HIE is also no more sensitive to X-ray energy than any other photographic emulsion of ISO 100-200, as far as I can tell.

Myth: Infrared energy is generated by friction.

Friction creates warmth, but this warmth is not enough to generate any appreciable amount of infrared energy. Proponents of this theory may be confusing infrared energy with static electricity.

Static electricity can certainly be produced by friction, and this can sometimes be a problem in photography. In certain rare cases, particularly when the ambient air is dry, friction caused by film winding can generate enough static electricity to leave lightning bolt or tree-shaped exposed marks on undeveloped film. This is a problem for any kind of film and is not one that’s specific to IR film.

Useful Web sites.

There are a lot of Web resources for information on infrared photography. Here are a few I’ve found of interest.

The Infrared FAQ. Lots of great information. (note: if you find the animated menu item in the corner as distracting as I do you may need to disable Javascript in your browser to make use of this page.)

http://www.cocam.co.uk/CoCamWS/Infrared/INFRARED.HTM

A useful introduction to IR photography:

http://www.handcolor.com/features/articles/infrared.htm

Information on the IR mailing list:

http://www.a1.nl/phomepag/markerink/ir_list.htm

Useful examples of the effects various filters have on HIE and EIR film:

http://www.coolmint.co.uk/infrared/guide/compare.html

A big comparison of various kinds of IR and near-IR black and white film:

http://www.pauck.de/marco/photo/infrared/comparison_of_films/comparison_of_films.html

A couple of useful articles on IR photography:

http://www.apogeephoto.com/mag1-1/mag1-IR.shtml
http://www.apogeephoto.com/mag1-2/mag1-2ir.shtml

Handy technical background to IR photography:

http://www.atsf.co.uk/ilight/tech/ilightec.html

http://www.rit.edu/~andpph/text-infrared-basics.html

 

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- NK Guy, PhotoNotes.org.

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