Q: I already contrasted them, but I need help on how to compare them. Any ideas? Thanks!
A: Contrasting and comparing should consider the same aspects, all this really means is to find the similarities and differences in the two images, where they meet up and where they differ. Some things to consider would be Composition, Colour/tone/shade, scale of both the image and what is portrayed, Depiction - what is the image of, does this show a particular era etc and how, Finish and surface - i.e texture of drawing paper against photographic paper, Strength of line and image etc etc If you have contrasted them you have already compared the two images - if by contrast you mean you found differences now look for what you find similar in both :-)