Went too far -- filmed by paramour, topless! (8)
I believe the answer is:
overshot
'went too far' is the definition.
(I've seen this before)
'filmed by paramour topless' is the wordplay.
'filmed' becomes 'shot' ('shoot' can be a synonym of 'film').
'by' is a charade indicator (letters next to each other).
'paramour' becomes 'lover' (I've seen this before).
'topless' means to remove the first letter.
'lover' with its first letter taken off is 'over'.
'shot' after 'over' is 'OVERSHOT'.
(Other definitions for overshot that I've seen before include "Went beyond the mark" , "Went beyond the target" , "Went too far" , "Went past the target" , "was pitched wrong?" .)