Is Aerochrome really lost? I can truly appreciate the mystique surrounding this film, on one hand.
But on the other hand, for me at least, it’s also been demystified. I think if you’re open to digital photography, then you have to conclude that Aerochrome isn’t “lost.” The process can be digitally replicated 1:1, including all its key characteristics. It just can’t be done with regular cameras/filters.
Nobody tells you that. What you read — or rather, what gets clicks — are claims like Kolari’s IR Chrome (which has absolutely nothing to do with Aerochrome), ultra-complicated trichromes or multiple-sensor experiments on YouTube, or new film stocks that supposedly imitate Aerochrome but have nothing to do with it.
Aerochrome is green, red, and IR. Blue is blocked — with a yellow or orange filter. The secret lies in the balancing and isolation of these three “color channels”: how much IR, how much green, how much red.
And this is where it gets tricky — it was the same with the original film. Just compare Richard Mosse’s photos.
Some have red vegetation, others pink, some with a blue sky, others cyan. I think the cause isn’t just vegetation type, weather/sunlight, and how the film reacts, but also factors like the lens (how much glass, how much IR gets through), the filter (yellow, orange — but which exactly?), and post-processing (white balance! Ever notice how most Aerochrome images have a cyan tint?), and of course the condition of the film roll.
Same goes for digital. Depending on the sensor (some let more IR through in certain ranges), the lens, and the filter, you’ll get different results — even if you’re using the exact same setup.
If you’re interested in digital Aerochrome, there are two solutions that, to me, do the original justice:
– Foveon sensor, ideally the SD1 with the green-red-IR filter from MidOpt and an “adjustment” filter to fine-tune the channels. Details here. This is 1:1 Aerochrome — no post-processing, straight out of the camera.
– For all other models, I’ve found a formula that works really well and is ultra-simple. But I recommend using CCD cameras. They just work. With most CMOS models, vegetation ends up looking too uniform or too pink, or the sky too magenta-heavy.
The camera — in this case, a D40x — has an internal filter that lets visible light + IR in the higher ranges through.
Then you only need one special yellow filter. Only this one produces the desired result. Use a different one, and the vegetation looks too uniform, the sky too pale or too violet, etc. All you need to do is shift the color channels (like the process in the original).
I just went outside briefly to demonstrate some Aerochrome traits:
– Greenish water turns blue
– tailights are green and/or yellow
– red cars are yellow
– yellow flowers turn white
– skin has a yellow/greenish tint, but shouldn’t be to yellow or green
