When I was in photography class in college, I created backplates in photoshop for still life portraits of small trinkets I was photographing. The photos were taken on black and white film and developed in the campus dark room. Led to some impressive photos. In our class's critiques, I explained how it was done. A lot of peers went from impressed to meh'd. The point: the black and white film laundered the new-age manipulation, and a digitally signed photo from a modern camera remains vulnerable to the same premise.