I had a theater-arts professor who told us that back in the days of B&W movies, the actors often wore garishly colored clothes to bring out certain contrasts in the B&W images. I mean, clownishly garish. He said in the trend of movie colorization, they’re just making up colors that look normal.
Not in the general case.
How would you distinguish from a shadow and a different shade of color?
*loses
This may be of interest.
NO. It appeared to be a washed out optical illusion version of what someone would actually see, and it can it demonstrates aspects of the three colour rods in your eye… a tri system. How Land does better is to uses wide spectrum filters centred on yellow. I think thats the trick. He tricks us by saying he accurately measured a yellow frequency… but thats not to say its light of only that frequency. If it was, that would never work… it was wide sprectrum… it carried red, green and blue frequencies, and thats how it was repaired by the projection lights, of unspecified colour property… I think its more of a system of white - colour1 - colour 2. Like with TV , we send L R and G, and B can be calculated. the two yellows allowed a repair to full spectrum, of sorts. But where is L ? not there. its repairing colour not intensity. Hence its not replicated except for observing optical illusions in the washed out situation… such as in shadow… our brains correct colour for the expected disturbance to the colour …reversing the disturbance to tell us our brains guess at the colour.
Shooting B&W film through different colored filters is deliberately used to add contrast between different colors that otherwise would show up as the same shade of gray. For example, a red or yellow filter can be used to increase the contrast between clouds and a blue sky. Some examples here:
Max Factor (Yes, the brand we know today was an actual person over a century ago) created a scheme that worked pretty well for TV to compensate for the response of image orthicon cameras.
And more about Mr. Factor:
Is this based on anything, or is this your own interpretation.
I have a hard time following what you’re trying to explain.
The early films and video cameras were mostly sensitive to bluish light. Red lipstick, for example photographed as black even if a bright shade of red - a common effect in photos of the 1920’s. I see a similar effect with normal lighting in the early days of video conferencing - with overhead light my bald head washed out, while the face was awful and dark and badly shadowed unless frnt lighting (very distracting) was applied.
I suspect the Max Factor process was designed to fix this issue - as mentioned, to lessen shine from the more reflective surfaces, darken those that faced upward and were too bright, etc. - all complicated by flesh being a reddish colour and so likely to photograph as a darker grey. Clothes would have the same problem. Red or brown were dark, blue clothes whiter. A lot of wardrobe choices, I’m sure, depended on how they worked with film.
As mentioned, panchromatic film solved the colour issues but still didn’t fix the issues with lighting and glare and reflectivity. There’s a reason a professional photo shoot or movie shoot spends a lot of time and effort configuring lighting.
As anyone who remembers the days of developing film and paper photographs will also attest - the other issue is contrast. the higher the contrast, the starker and more monstrous faces appear.
In fact, AFAIK, this is how virtually every color image – film, analog electronic, or digital – has been captured: monochrome sensors with different color filters record separate images which are combined to recreate a simulacrum of the original scene. Early color film systems used two or three color filters; later single-strip color films used emulsions with three layers that absorbed one color and passed the others; analog color TV cameras had three tubes; and digital sensors have three color filters over the subpixels.
I don’t know of any color imaging system that uses a method other than capturing and combining multiple filtered monochrome images. The number and color values of the primaries vary, but the principle is the same in all systems, film, electronic, or digital, still or motion.
That’s not quite how conventional color film works. Rather than using filters they have multiple layers of silver halide, each of which is chemically sensitized to only a portion of the spectrum. The only filter required is a yellow one between the top blue sensitive layer and the rest, which is necessary because all silver halides are naturally blue-sensitive. You can see this filter if you look at color negatives which have a strong yellow cast even in the clear areas. In color slide film the filter is chemically removed during the processing.
Cool thread. Now that the question has been answered, I’ll mention this: The only public Rolling Stones concert appearance in all of 1968 - the year of their iconic album “Beggar’s Banquet” — was a more-or-less-surprise 2-song set at the New Musical Express Poll Winners show, in May. Many, well publicized still photos of the performance have been around since then, but nothing at all of color — until about 30 seconds of some spectator’s (sadly, silent) super-8 color movie film showed up, just a few years ago. Suddenly, we realized Mick Jagger’s shirt that day had been light blue, not beige or white.
Minor detail, I know. I just thought it was interesting that a supremely famous rock band at their peak left almost no color photo evidence, nor video, nor even a scrap of audio, for this key event, as if it were something from the Crimean War rather than late 60s London.
Not entirely correct. Lippman photography captures the image in the form of an interference pattern that is reconstructed by a white light source resembling the original as closely as possible. It really does capture the true spectral colors, and doesm’t use any sort of tristimulus separation into 3 colors. An alien who had eyes that worked on a 4- or 5-stimulus system would see a Lippmann photograph in its true colors, but would be confused by our standard 3-color images.
Lippmann photography has much in common with holography, but there are a few significant differences.
Lippmann colors, since they derive from the illuminating source and an interference pattern, never fade. A Lippmann photograph looks as brilliant when viewed as when it was taken, even if it was taken a century ago.
Thanks, @CalMeacham. I didn’t find that in some quick and half-hearted Googling, but I knew that someone here would know if there was a non-filtered color system. I look forward to learning more about the Lippmann process, which I had never heard of before.
Welcome to the SDMB, @QMatic, and thanks for your accurate and more detailed explanation of color film. However, at the risk of being pedantic (a risk I take every day 
) I don’t believe I said that color film used filters, but simply gave a slightly less technical description than yours.
Regarding the OP’s question, have a look at this journal article from 1969:
Mueller, P. F. “Color image retrieval from monochrome transparencies.” Applied optics 8, no. 10 (1969): 2051-2057.
Unfortunately, you can only access the article with an OSA membership or through a university library. The article is cited by 64 other publications:
https://scholar.google.com/scholar?cites=15127538524365798517&as_sdt=40000005&sciodt=0,22&hl=en
Though, if I’m understanding that correctly, that method requires that the picture be taken using special procedures, and it wouldn’t work for just any old black-and-white picture.
That has to be correct. A simple thought experiment demonstrates that it is impossible to definitively determine the colour of an object from an ordinary monochrome photograph:
Suppose we have a photographic emulsion that is more sensitive to green light than red; we take a photo of a three balloons (one green, one red, one white) - in the monochrome photo, one balloon looks lighter than the other, and it is the red one, because the film reacted more to the red light from that baloon. The green balloon appears darker than the red one in the photo. (The white balloon must appear at least as light as the red balloon, as it is reflecting at least as much red light as the red one - in reality, the white balloon is the lightest one in the photo)
But we can still determine which one was green, right? Well, no, because it must be possible to make a fourth balloon that is some shade intermediate between the green and white, such that it appears the same lightness as the red balloon, when photographed in monochrome (but the balloon actually appears some pastel shade of green in real life)
Just realised I meant to say more sensitive to red (for the rest of the post to make proper sense)
I’ll throw in that the Lone Ranger’s mask was purple because that produced the shade of black the directors were looking for. That original mask was featured on the Antique Roadshow.
Did the gelatin contain any other trace chemicals that might have reacted with other wavelengths differently? Not forming visible silver but still leaving information that could be obtained at later dates?