http://www.ign.com/wikis/the-amazing-spider-man-game/Amazing...Note that you can check which one's you have by going to your email and hitting Y to filter for "Bestiary" and there will be an email for each enemy that you have taken a pic of.
In conclusion after getting the achievement myself, I had completed, as in 100% missions and side missions, the game on super-hero difficulty and then played selected chapters to acquire the pictures of enemies. I found S-03 and S-01 already in my email before I started my task, assuming maybe I got these by defeating the game or a side quest even, not sure. The achievement popped after I took all enemy pictures except for the seeker. Just figured to let everyone know.