Facebook's new lightbox style photo viewer is a bit of a love/hate thing for me.
Image from azharkamar
One side, it shows pics in a larger resolution and makes flicking through a lot easier.
On the other, its huge and pushes down the tags/captions/comments so I can't see shit Captain!
To temporarily disable it for the current photo, simply press F5 and it'll refresh in the old view.
Unfortunately, the temporary fix will re-enable the theatre once you click on the next photo.
To stop that, edit the URL for the current page and remove the "&theatre" bit at the end.
I'm sure there's a more permanent way of fixing it using a Greasemonkey script but I haven't gotten to that point yet.