I just rolled out photo search. As part of that, I cleaned up and modernized the photos pages a bit.
Right now, photo search will search all photos over all the albums in your group. If the match is with an album title or description, all photos in that album will be returned. I may change that in the future to do some sort of collapsing, but that will require some work.
The search does partial word matches on photo names, but not on other fields.
This involved a lot of changes and the 'paint is still wet' so to speak. Please let me know if you see any bugs.