A colour film that can see things human eyes can’t.
Kodak Aerochrome is the only colour infrared film ever made. There isn’t much of it left; the supplies are so low now that you may find yourself dishing out over $200 for a single 35mm roll in 2021.
Aerochrome, also known as Kodak EIR, has been long discontinued (in 2009) as the military, forestry, and creative industries that benefitted from it have switched to digital sensors. Today, it’s a highly sought-after emulsion for photographers wanting to try something truly exotic in a film camera.
Aerochrome has a layer sensitive to near-infrared light coupled to bright red pigments. When pointed at foliage, certain types of clothing and other things that reflect infrared, the pigments light up, giving the image eery blood-like highlights in those places. The strength of this effect is dependent on the filter used in front of the camera lens.
To better understand the creative (and scientific) power of Aerochrome, I will be comparing it against a more common — and more affordable — colour-shifted film stock that can also produce eery colour palettes: Lomocrhome Purple.
Lomography’s Lomochrome Purple is not sensitive to infrared light. Instead, this C-41 emulsion scans and prints as if all the greens have been painted purple. Lomochrome Purple is a widely available film stock, much cheaper than Aerochrome; it was deliberately created in an effort to emulate Aerochrome.
If you know what you’re looking for, feel free to skip to the following sections: science & history, handling film, choosing your scenes & subjects, lens filters, exposure guide (Aerochrome/Purple), focusing on infrared, developing (Aerochrome/Purple), scanning & post-processing, and where to buy Aerochrome/Purple/filters/gear for shooting IR.
Download (free) sample scans of Lomochrome Purple and cross-processed Aerochrome.
Both Aerochrome and Lomochrome Purple are highly interpretative emulsions. To see how they may pan out for you or just to play with the really expensive negatives, get your ☟
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The science and the history of Aerochrome film.
William Herschel discovered infrared light in the year 1800 as he measured the temperature of different light colours, split by a prism. The blue end of the spectrum appeared to give out the least heat while red — most. However, he also found that an area beyond the red light (away from blue) gave the most heat, despite the lack of colour. That invisible light is now known as infrared (IR) light, and it’s being utilized in a large variety of modern applications — from weather maps to COVID screening to the sensors in film scanners.
Aerochrome was developed in the 1940s by Kodak for the military to help detect camouflaged equipment. They were able to create a colour film that had its red dyes light up in response to the chlorophyll in leafy vegetation due to its reflective IR properties. However, those red pigments stayed dormant in response to green paint, giving those who studied it an easy way to detect enemy positions.
The effect of foliage’s response to infrared is known as the Wood effect. However, trees aren’t the only things that reflect or emit IR. With time, more precise instruments were developed that can see in the dark and measure temperature accurately enough from a distance to detect a slight fever. The need for colour IR film has sharply dropped since the introduction of digital sensors, but by that time, Aerochrome had found its new audience in psychedelic photography.
My all-time favourite album by Jimi Hendrix, “Are You Experienced?” featured a photograph by Karl Ferris that widely popularized Aerochrome in the 1960s. The film’s incredible colour palette dyed the world in amazing, bright colours while allowing somewhat natural-looking skin tones (since humans don’t reflect IR, we only emit it).
Unfortunately, Aerochrome’s newfound fame in the art world spelled its eventual demise as its strong effect fell out of favour along with the end of the psychedelic era. In just a few years, its clout dropped from being the material for expensive album covers to “deep-fried” amateur failures.
Just before the film got discontinued in 2009, two people acquired huge stocks of Aerochrome:
Dean Bennici sourced huge quantities of the uncut emulsion in hopes of distributing it to the photo community; his supplies are now almost completely dry. Richard Mosse found 16mm movie reels and large quantities of still film and took them to war-torn Kongo to document the conflict in this film’s incredible colour.
Today, Aerochrome can still be found on eBay for large sums of money from the few who held on to the last precious rolls. Certain digital workflows have been developed that let you either alter your image’s palette or utilize certain camera’s IR capabilities to simulate those candy pink colours. But the most straightforward way for film photographers to get some of the eery effects of the film in-camera is to use Lomography’s Lomochrome Purple film.
Like Aerochrome, Lomochrome Purple senses visible light and records it in a slightly altered palette (i.e. colour shift). While the colour IR film would change red to green and green to blue, Purple renders greens as purple and purples as green. Unfortunately, Lomography’s film does not feature an infrared-sensitive layer, and its colour palette isn’t as wide and vivid. But the idea of an altered view of the world remains.
✪ Note: Aerochrome’s false colour reds that glow in response to infrared aren’t the same as Lomochrome’s colour shift from green to purple. Aerochrome uses colour to represent something invisible, while Purple takes the very visible green and only changes how it appears on film.
Getting started with Aerochrome & Lomochrome Purple — handling film.
Aerochrome was developed to be flown at impossibly high altitudes in military planes. When frozen, it seems to last way past its expiration point. It is not a flimsy emulsion. However, the nature of infrared light makes it inadvisable to use in certain plastic cameras or loading in broad daylight. The IR spectrum may penetrate the light seals and fog the film with a bright red wash. You should also not load it into cameras with automatic film transport as they often use infrared sensors to count the frames. My rolls had been hand-spooled by Dean Bennici, and I was advised to be very careful near the last frame not to tear the entire strip off.
Travelling with Aerochrome. Aside from temperature shifts, which this film should handle for a few months out of the freezer, the greatest danger is the X-ray machines at the airports. Even though this film responds to IR, which is quite far on the light spectrum away from X-rays, it is quite sensitive and may get fogged after a few runs through one of those machines. It’s best to ask for a hand check — more details about travelling with film here.
Handling Lomochrome Purple, on the other hand, is exactly like any other 35mm colour film: simple.
Choosing your scenes and subjects.
Neither Aerochrome nor Lomochrome Purple is considered to be a general-purpose stock. Both films work great with foliage, but I found them particularly pleasing when exposed to the large, sweeping landscapes without the busy network of branches and leaves of a forest.
Aerochrome can actually be used for portraiture, provided you choose your filter well and spend quality time colour correcting your work. Human skin does not reflect enough IR for this film to glow red and thus could be made to appear natural. The lips, however, will appear yellow.
Besides adding a red glow to represent infrared light, Aerochrome will change some visible colours as well. For example, it will render red as green, and green as blue (Applied Infrared Photography, 1972, pp. 4-5). You can see this happen in the photo below, where the stoplight glows green, and the Toys “Я” Us logo has its colours altered.
I like the contrast Aerochrome provides with concrete/stone surfaces, water (that may turn black) and sky. Trees covered in snow are also an interesting combination.
I would avoid using Aerochrome in scenes comprised exclusively of foliage. You may be able to achieve the same “red glow” effect with any colour or black and white photo by tinting the whole thing red. However, flowers do not reflect IR as the leaves do, so there actually may be some interesting foliage-only applications. Oh, and there’s also an interesting body of work documenting trees recovering from forest fires in Australia.
You may also consider shooting things that reflect little or no IR, like the glaciers on Aerochrome. They won’t glow red but will still look unusual.
Lomochrome Purple isn’t great with skin tones unless you plan to make your subjects look purple, red, or blue.
In the forest, Purple will keep colouring the leaves blue-red, but the trunks will largely remain their actual colour — depending on your post-processing — (in contrast to Aerochrome, which will paint both in red).
Just like Aerochrome, Purple will not colour flowers purple — but for a different reason. Aerochrome will not pick up the red glow from blossoms because they do not emit infrared light; Purple — simply because they aren’t green.
Peculiarly, your purples will turn green with Lomochrome Purple.
I also found Purple to be a bit more fine-grained than Aerochrome. It is more uniformly coloured (purple), and there’s less noise. Thus it is easier to shoot — although I found the results a bit more predictable as compared to the more expensive stock.
There’s no need for colour filters on Lomochrome Purple to get the intended effect.
For Aerochrome, however, Kodak recommends their Wratten #12/Y52 (yellow) filter, but that’s just a suggestion. Even more so with my camera that has a limited supply of colours available for its unique seventy-year-old foldable lens barrel. So I tried a few different ones.
Because modern use of Aerochrome film isn’t practically scientific, your filter choice is a matter of taste. As you go through the examples in this section, you’ll notice that the denser filter colours will yield stronger results, and your choices of hues aren’t necessarily limited to the yellow and orange glass.
Red & orange filters are for the “insane mode.” Because there are no dense red filters available for my Vitessa, I haven’t tried that end of the spectrum, but I’ve used something close: 133/28 (dense) Orange. The results that I got and seen online with these kinds of gels are very strong, heavily tinted with reds & pinks. Everything looks deep-fried with an unsavoury amount of saturation. Not a fan.
Other than the final image colours, red and orange filters tend to tint Aerochrome’s film base when developed as a slide film. The result is a series of frames that look a bit yellow and may require considerable post-processing, which you may not want out of your film.
Another thing to note when it comes to strong colour filters (like dense reds and oranges) on top of Aerochrome is that the red pigment is made of very large grain particles. On 35mm film, its excess can make your photos lack detail, especially when enlarged.
Yellow filters. With Aerochrome, I tried two yellow filters on my Vitessa: 125/22 G2 and 133/21 G1. The former is a typical yellow filter that you’d use with your black and white film to highlight the clouds, and the G1 is a slightly less tinted version of the G2.
125/22 G2 seems to have accomplished colours that I associated with some of my favourite photos taken on Aerochrome — deep blue skies, cotton candy foliage and strong contrast overall:
133/21 G1 gave milder results; however, I found those to be a lot easier to work with. As I describe in further detail below, my goal with processing this film is to make the scene look as natural as possible, with the IR glow adding a hint of something alien. The mild-yellow 133/21 G1 gave me just the right palette to bring that vision into life:
Green filters. An old article from 2012 inspired me to go beyond the red-orange spectrum.
Most people recommend either a yellow or orange filter but you can also use a red or even a green filter. In general, the darker the filter, the darker the reds and sky, and the greater the contrast. The lighter the filter, the pinker the reds and greener the sky.
Indeed, this is an expensive film, but I have a couple of rolls tucked in, and the experiments with the filters aren’t meant to be complete failures — just different effects. So I went for the green with my 133/26 Gr1 to see what would happen:
The fact that the green filter worked was great; it wasn’t a very dense gel, and hence the IR effects appeared to be tastefully mild yet clearly visible. However, I found it difficult colour correcting the image, particularly the grey stones that stubbornly remained blue-tinted despite my best efforts in Photoshop.
85C is a mild warming filter that looks like a variant of orange. This colour gel is usually used to shoot tungsten-balanced film, like CineStill 800T, in daylight. Turns out that it also works well with Aerochrome:
Overall, I was pleasantly surprised that all the filters produced workable results with my Aerochrome roll. I like 133/21 G1 and 85C for mild, somewhat natural-looking results for my personal projects.
Old mechanical film cameras may not always have the choice of exact filters. It is, therefore, great to learn that Wratten #12 isn’t an irrefutable dogma that limits Aerochrome use. Whoever gets to use this wonderful film has plenty of choice for hues, from deep reds to greens, in various densities without losing that elusive IR glow.
Aerochrome’s box rating is ISO 400. However, this rating is meant to be implemented with the filter already screwed on; hence the real sensitivity of this emulsion is more like ISO 200 (assuming it’s been engineered to use Wratten #12/Y52 filter, which needs to be compensated for by one stop).
Aerochrome is easy to under- and overexpose. Its dynamic range is very narrow, with little latitude left for mistakes, making it difficult to shoot.
What’s worse is that the infrared light and the red dyes in Aerochrome that represent it do not necessarily behave as you may expect. I found IR bouncing off and colouring objects around the foliage and increase in intensity dramatically when the sun is at such an angle that most of its rays reflect off a surface at a right angle towards the lens. The best direction to point the camera with Aerochrome turned out to be away and to the side from the sun, avoiding direct light and reflections. High noon is also not a bad option as the sun is usually way out of frame.
Another peculiarity of working with this film is the insanely strong glares that IR seems to produce. My guess is that most lens coatings aren’t equipped to deal with the infrared light spectrum, hence this:
To be fair, it’s hard to say exactly what may be causing the red overcast in the above shot. It may be the reflected IR from the grass and foliage colouring the grey boulders — or it may be due to fogging while handling the film. However, this frame was uncharacteristic compared to its neighbours; hence I’m suspicious of the sun washing over everything with the red.
My suggestion is, therefore, to be extra mindful of the sun’s rays and their reflections and use a lens hood. In my experience, Aerochrome looks better when slightly underexposed than overexposed.
Exposing Lomochrome Purple.
Lomochrome Purple is a part of Lomography’s XR, “extended range,” series of films. Its box speed is anywhere between ISO 100 and ISO 400. However, the effect (i.e., amount and quality of the purple tint) may depend on the amount of light the emulsion receives — though it is easy to alter those colours in post.
Exposing Lomochrome Purple is much, much easier than Aerochrome.
To ensure the least loss of information on my negatives, I typically expose my Lomochrome Purple at EI 200 and then work on the final look in post.
Focusing on infrared with Aerochrome.
Another unique peculiarity of infrared film is the focus shift. While camera lenses are made to correct the differences in how the red, green, and blue wavelengths converge on the film plane, IR light is often ignored. Some older lenses have a focusing aide (commonly marked in red R) to help you get sharper images of this invisible light.
Due to its longer wavelength, the IR channel may look sharper if you shift your lens’ focus a little closer than the object of interest. However, the amount of shift is hard to tell because the actual recorded infrared wavelength depends on the film and its diffraction depends on the lens.
Thankfully, this artifact isn’t very strong with Aerochrome. As you can see in the photo below, even at a very shallow depth of field, the infrared glow appears to be sufficiently in focus.
Though most will tell you that Aerochrome is a slide film and should be processed in E-6, that isn’t exactly right. It is actually meant to be processed in AR-5 chemicals, which technically makes both E-6 and C-41 the cross-processing options.
I’ve tried both ways and found that the results are almost identical; the only difference is having to flip the colours on the negative. Aerochrome’s negatives (cross-processed in C-41) are somewhat green-tinted (by the red dyes from IR), but the film base is clear, making scanning a very simple task. I have not tried printing my Aerochrome negatives via an enlarger, but once I do, it will have to be from the negatives.
Whichever way you choose to develop your film, always ask your lab to be extra careful with your film, not to expose it to any light (even the safety light).
Developing Lomochrome Purple.
Lomochrome Purple is meant to be developed in C-41 chemicals, available at all labs that develop colour film.
Peculiarly, Lomochrome Purple has a green film base, similar to how Aerochrome appears when developed in C-41. However, the green remains if you cross-process your Purple as a slide film in E-6, making it somewhat unsuitable for a projector or casual viewing.
Scanning and post-processing.
Neither film is particularly hard to scan. Right after you get the image from your device, either your software will automatically adjust it, or you can do this by hand by first inverting (if that’s a C-41-processed Aerochrome & Purple) and then equalizing.
My objective for most of my colour images is to ensure that the hues that I can recognize appear as close to reality as possible. For example, skin tones and neutral greys like stones and concrete are to look natural. Following this rule, specialty films like Aerochrome should pull in the viewer through recognition that it is not a painting and add more interest with elements out of the ordinary. As long as no part of the picture is separated and the entire process of colour correction occurs wholistically, the film should retain its “voice” (whether it’s Aerochrome or Portra).
I may, sometimes, choose to correct colours differently for different zones, such as adding more red in shadows while increasing blues in the highlights. However, this is not the same as masking a person and doing separate colour work on them.
When it comes to contrast and sharpness, I have a more loose objective, which is making sure that the points of interest are clearly and immediately discernable while at the same time avoiding an unnatural “deep-fried” appearance.
Saturation I usually do not touch.
Another thing that I do to my scans is cleaning up distracting dust and scratches with the Spot Healing Brush tool.
My digital workflow for colour correction is entirely in Adobe Photoshop, limited to Curves and Color Balance adjustment layers.
With Aerochrome, like with Lomochrome Purple, some shots just work; however, others require some work. The trickest shots turned out to be the ones that got awashed with IR flares, shot with unsuitable colour filters, or improperly exposed.
Unlike Lomocrhome Purple, with the right filters, Aerochrome will retain its red highlights while allowing you to ensure correct skin and sky colours. I’ve also noticed that certain types of clothing may reflect IR (despite not being green in visible light).
Lomochrome Purple will only colour green foliage and shift the rest of the colours along the way. With Purple, it is more difficult to balance skin tones since bringing them to a more natural hue removes the purple highlights from the rest of the scene and darkens the colours overall. But it would be a lie to say that it can’t be made to look as good as Aerochrome:
Where to buy Aerochrome film.
I highly recommend you check the seller’s reputation and film description. My purchase was in bulk from an American photographer who decided to unload his supply a couple of years back.
❤ By the way: Please consider making your Aerochrome film purchase using this link so that this website may get a small percentage of that sale — at no extra charge for you — thanks!
Where to buy Lomochrome Purple film.
Getting Lomochrome Purple is much easier: most places that sell film will have it.
❤ Please consider making your Lomochrome Purple film purchase using this link so that this website may get a small percentage of that sale — at no extra charge for you — thanks!
Cameras, filters, and other equipment.
Though it may be tempting to shoot Aerochrome in a half-frame camera, it is rather grainy — something to keep in mind. You will also need to ensure that you use a fully mechanical camera, preferably with a metal shell.
I don’t think you will need a tripod or anything else for either emulsion — they are both fast films meant for hand-held operation.
Good luck with your film, and please let me know if you got any great results or more tips!