Yes. There's just not a single one across all faces - but I wasn't meaning that.
What I mean is, we know the kind of tints a face will have. A face is not suddenly going to be blue or green or poppy red. And by how light a black and white face appears, we can tell quite well if it's a darker one (oilish to brown) or lighter (pinkish towards more pale).
If we get it wrong within a range it's no big deal. Color film stocks would also vary it widely.
Hell, even actual people who met the person we colourise in real life will remember (or even experience in real time) their face's hue somewhat differently each.
Black and white films of different technologies and manufacturers and eras actually lighten or darken skin tones. Really very significantly.
And it's not going to be obvious from the final positive, unless there's _extensive_ data with those images about how the photography was done. And there never is.
Editing because I can no longer reply: the question of whether a skin tone is a dark one or a light one has had severe real life impacts on people whose lives are now only represented in photographs. You can't write this off as micromanagement; it's about the ethics of representation.
>But how brown? How pink? How light? How dark? This is an enormously important issue
Is it?
If 2 colour film stocks took the same image of them, it would show their hue a little (or a lot) different.
Even if two different people actually met the same person, they will probably describe their face as slightly different tones from memory. (And let's not even get into different types of color-blindness they could have had).
Hell, a person's hue will even look different to the same person looking at them, in real time, depending on the changes in lighting and the shade at the scene as they talk (e.g. sun behind clouds vs directly sun vs shade vs bulbs).
It's not really "enormously important" to micromanage the (non-existent) exact right brown or right pink.
I can now reply so I will say what I added in an edit: the question of whether a skin tone is a dark one or a light one has in the past had severe real life impacts on people whose lives are now only represented in photographs.
You shouldn’t write this off as micromanagement; it's about the ethics of representation. It is better to leave the original image uncoloured than to colour it automatically based on some fundamentally ill-informed model.
Hand colouring that image based on individual knowledge (for example that someone could or could not pass as white) is ethically better, if colourised images are needed.
Important nuances of culture and history, important and complex stories of discrimination and survival, are damaged by automatic colourisation by models that have no knowledge of the source of the mono image they are colourising.
I also remember reading articles about film stocks on the same subject. But in light of the actual tangible harm caused to blacks, I think worries about the exact shade in photos, are basically overcompansating for things that should have been (or still should be) improved outside the realm of film stock/photo retouching...
Which makes it mostly american baggage. Other places who didn't have that history don't have much of an issue with whether a person is shown this or that exact shade in a photo, as it doesn't change anything, the same way making a white guy a little pinker doesn't change anything.
Yes. There's just not a single one across all faces - but I wasn't meaning that.
What I mean is, we know the kind of tints a face will have. A face is not suddenly going to be blue or green or poppy red. And by how light a black and white face appears, we can tell quite well if it's a darker one (oilish to brown) or lighter (pinkish towards more pale).
If we get it wrong within a range it's no big deal. Color film stocks would also vary it widely.
Hell, even actual people who met the person we colourise in real life will remember (or even experience in real time) their face's hue somewhat differently each.