In advance, get lost camera accessory (4,4)
I believe the answer is:
lens hood
'camera accessory' is the definition.
The definition suggests a singular noun which matches the answer.
'in advance get lost' is the wordplay.
'in' means one lot of letters goes inside another.
'advance' becomes 'lend' (I've seen this in other clues).
'get lost' becomes 'shoo' (both can be said to tell someone to go away).
'lend' enclosing 'shoo' is 'LENS HOOD'.
Can you help me to learn more?
(Another definition for lens hood that I've seen is " Camera attachment".)