Challenge Accepted

To anybody who missed out on the PhotoSoc Pub Quiz, or thinks they're any good at photography, here's a challenge!
In case you've never seen the TV show Only Connect (I wouldn't blame you, only Shane has really...), in the grid are 16 photography-related terms which can be grouped into 4 categories. The groups have to be identified, as well as the connections relating the terms to each other.
It's not easy and there is only one correct way to solve the grid. During the pub quiz, only one team out of four teams of six people managed to solve it entirely!
Shane and me had a lot of fun designing this and to be honest, we're quite proud of it! So have a go and let me know if you think you know the solution.

peace