What crack photographers do? (4)
I believe the answer is:
snap
'do?' is the definition.
(I know that snap is a more specific form of do)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for snap that I've seen before include "Break off - card-game" , "Unpremeditated - bite" , "Simple card game - gotcha!" , "Collapse" , "on the spur of the moment" .)