Monochrome IR film - also known as CD (for Camouflage Detection) 35 mm and 120 roll film is still around; but I last used it at School about 35 years ago. Because it is responding to a different wavelength, you have to adjust the lens according, as the IR is bent differently in the lens. Decent fixed focus lenses in the 1970s and 1980s would have a small red line on the focussing ring which the point of focus should be moved to if using IR film. I remember the superlative Pentax 'Takumar', Nikon 'Nikkor' and Leica 'Elmar' lenses all had them - as does my 1939 Zeiss Ikon Super Ikonta - used widely as a military camera. However, none of my later Nikkor AF lenses from the 1990s (for film cameras) have a marking, nor do my post-war Zeiss Ikon Contaflex SLRs, which were very expensive cameras at the time. If I recall correctly, 35mm cameras were carried on the Nimrod MR2, using B/W film, for rigging Soviet ships and I have a feeling that IR film was also used a few years back. (Olympus OM2 cameras spring to mind - perhaps someone can confirm what were used?). I certainly recall seeing IR photos from film earlier in my career, and not from IRDS systems.Yes.
Education Center - K-12 News and Views: After World War II, many uses were developed for camouflage film, also known as color infrared film, in agriculture.... Karl SteddomTexas Cooperative Extension Pictures can be very useful in science and have been so for over seventy-five years. In 1927...www.apsnet.org
At the height of World War II, the US military commissioned Kodak to produce a new type of color film that could capture infrared waves invisible to the human eye. The resulting photographs, taken during aerial reconnaissance missions, allowed allied forces to distinguish between foliage and the...edition.cnn.com
If I was using IR film today, I would push the film speed and stop down the lens to get around this issue - none of my present 35 mm cameras have such markings on their lenses. I might try to track some film down.
You can get a good approximation of IR film with a deep red filter and B/W film; not exactly IR, but it cuts out the shorter wavelengths and atmospheric scatter and reveals quite a lot of detail on landscapes and darkens clouds, making for very dramatic photos.
ETA: On this Mamiya Sekkor lens on my Mamiya 645 (c 1980), the red IR focus setting can be seen at F4, to the right of the focusing mark on the depth of field scale. Note to self. This lens is externally very dusty and needs cleaning!
AETA: On A well-known auction site, monochrome 35 mm IR film is between £6-11 for a roll.