You heard me right, folks. You can take color photos with black & white film. And no, I’m not talking about colorizing images after the fact, which is basically a glorified paint-by-numbers.
Decades before the first commercially popular color film hit the shelves in 1935 (Kodakchrome, in case you were interested), Russian photographer and chemist Sergey Prokudin-Gorsky pioneered a technique called trichrome or trichromy. Without going into an uninteresting amount of detail, I’ll just say any color image can be made up from three colors of light - red, blue, and green. This is how your computer monitor works, and most digital camera sensors (Bayer sensors). It’s actually also how the color receptors in human eyes work. To my feline blog readers, I apologize in advance that this will not work properly for you.
Extrapolating on the concept that red, blue, and green light can combine to make any color in the visible spectrum, Prokudin-Gorsky traveled all over the Russian empire as early as 1904, capturing images on three frames of black & white film: once through a red filter, once through green, and one blue. Prokudin-Gorsky had to then use various analog processes to come up with a final color image to display. Now that his negatives are mostly in the US Library of Congress and have been digitized and combined into color images, you can go check out awesome true color photos of what pre-Soviet Russia looked like more than a century ago. What an absolute trip.
Unlike dear Sergey, you and I have the luxury of combining scanned images in Photoshop.
So how do you do it? Well you need a camera and lens that can shoot film and hold filters. Basically any 35mm SLR will do, although there’s no reason you couldn’t shoot larger formats the same way if you wanted to. You’ll also need 3 very specific filters. A 25a Red filter, a 58 Green filter, and a 47b Blue filter (which, note, is different than just a 47 Blue). 25a Red filters are commonly used in B&W photography and not difficult to source. These specific green and blue filters are rarely used for anything other than thrichrome photography, so they’re kinda obscure, but I didn’t have too much trouble finding them at B&H.
I’m using my trusty Olympus OM-G. Why? Honestly, because every single lens I have in the OM mount (24mm, 28mm, 35mm, 50mm, 75-150mm) uses a 49mm diameter filter. So I could cheap out and buy very small filters that don’t cost much, and they work on all of my lenses. I got all of my filters for just north of $50 total.
You’ll also want a sturdy tripod. These legs and this geared head are overkill for a 35mm camera under normal circumstances. I bought them with my 4x5 in mind. But the extra rigidity is nice when you need to get as close to perfectly matching frames as possible. Note that I’m also using a cable release to minimize camera movement.
I collect bubble levels.
Also I would be remiss if I didn’t mention that I designed and printed a magnetic filter attachment system to save myself the trouble of screwing in and unscrewing filters a billion times for every roll of film. If you want to print one, it’s on Thingiverse.
Meter and expose carefully. I use the filter factors to calculate exposure for each frame. With HP5+ film, I seem do be doing quite well with adding 3 stops for the red filter, 2 2/3 stops for the green filter, and 2 1/3 stops for the blue filter. If you are off on your exposure, your final color blend will be wrong and your color balance will come out weird. I also make it a point to always expose first my red frame, then green, then blue, in that order. “RGB” is a common acronym, and consistency with what order my exposures go in on the film strip helps me keep things straight after the fact.
With any kind of motion in the photo, expect an interesting rainbow effect, or CMY/RGB ghosting where things didn’t overlap perfectly between frames. This is particularly common in moving water, leaves on a windy day, etc. Rocks and trees are pretty good at holding still. People, not so much.
Once everything is combined, you can flatten, crop, and proceed with any further editing you’d like to do. Here’s video showing my first attempt where I did kind of a proof-of-concept to see if this was worth pursuing anymore (spoiler alert: it is). If you’re in a rut and want to try something new to get the creative juices flowing again, go pick up some filters and give trichromy a whirl.