I was planning to do a 100% completion run, including a full Hyrule Compendium. About halfway through the game, I realized I never took a picture of my first dungeon boss. I didn't worry too much at first, since you can buy additional pictures in Hateno, but now that I bought every single monster picture available, that boss is still missing (as well as a few others, which I assume to be the final boss and some special enemies I haven't seen yet).
Is there any way to still get a picture of dungeon bosses and complete the compendium? Obviously I don't have any save files from before I fought that boss, and even if I did, I'd have to pretty much re-do the entire game.