He closes part of the camera (7)
I believe the answer is:
shutter
'part of the camera' is the definition.
('shutter' is part of 'camera')
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for shutter that I've seen before include "Removable cover" , "Device on a camera, it opens and closes" , "Moveable window screen" , "Hinged window cover" , "application for Windows?" .)