Hmmm...just noticed that word: "collagist." 'Never heard that one before.
Anyway, the point of this post is to draw your attention to a good article on collage from the point of view of a National Geographic photographer, and an even better set of collages by various artists (just keep scrolling down): here.
I'll be curious to hear what y'all think...one thing that really strikes me is, if a National Geographic photographer is celebrating collages made with the magazine's collages, then copyright infringement is truly not an issue. And I've always worried more about using Nat Geo images, than almost any other source!