Crack marksman gets the picture (8)
I believe the answer is:
snapshot
'the picture' is the definition.
(snapshot is a kind of picture)
'crack marksman' is the wordplay.
'crack' becomes 'snap' ('snap' can be a synonym of 'crack').
'marksman' becomes 'shot' (I've seen this in other clues).
'snap'+'shot'='SNAPSHOT'
'gets' is the link.
(Other definitions for snapshot that I've seen before include "exposure" , "Bit of camerawork" , "pic" , "Instant record of an event" , "still taken quickly" .)