CMYK … but isn’t it required to be able to process a photographs that will look same on screen and on paper while printed ?
No!
That has nothing to do with it.
Somewhere, I have a gamut (color space) comparison
between CMYK and sRGB, printed on a good paper as well as
on a bad paper.
Here is the first link: Having fun (?) with printing profiles -- paper/gamut comparisons...
And here is the second: Color Printing 101: the RGB & CMYK gamuts – ImageBlog