Sorry, no, a photograph (sans macrolens) isn't going to provide the necessary level of detail.
I use a 30X 'pocket microscope' - a reticule would work just as well - to reveal printing techniques.
Maybe I just need to look at more of them, but even a 2400 dpi scan - which will help you distinguish real photos from half-tones in a heart beat - does not capture the level of detail needed to distinguish collotype from rotogravure, or to distinguish the different types of half-tones.
(Part of the problem may be that my scanner has a low optical (physical) resolution, and is algorithmically boosting its resolution. I went fishing for the original specs, but the manufacturer does not have the documentation online for my discontinued product.)
I am very interested in printing & colorization techniques, and wish you the best.
The Mad In Pursuit blog has about the best high-mag examples I've seen 1) on line, and 2) in one place.http://www.madinpursuit.com/Tutoria...cardRef2.htm
... for black'n'white postcardshttp://www.madinpursuit.com/Tutoria...ardRef3.html
... for color (and colour) postcards
As always, remember that these 'reference' websites are put together by volunteers on a samples-available time-available basis, and that different people have come to understand different technical terms in different ways. For example:
Q/ Are there differences between 'hand-colored', 'hand-painted', and 'hand-tinted'?
Q/ Do people use these terms consistently? (Okay, that's easy: "NO!")
Q/ How can I tell the difference between colors added to a photograph by the use of a photo mask and color-sensitive emulsion, versus a mask and brushed-on tinting, without calling Abby Sciuto?
Q/ Does the use of a mask & brush qualify as 'hand' work, or does 'hand' necessarily mean 'free-hand'?
I hope you get the bug, learn more, and come back & tell me.