Start where film is shot (5)
I believe the answer is:
onset
'start' is the definition.
(both can mean the beginning of something)
'film is shot' is the wordplay.
I cannot really see how this works, but
'film' could be 'et' (E.T. the Extra-Terrestrial) and 'et' is located in the answer.
The remaining letters 'ons' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'where' is the link.
Can you help me to learn more?
(Other definitions for onset that I've seen before include "Advent" , "Start - opening moments" , "Beginning; violent attack" , "Initial stage; attack" , "Assault; start" .)