Shutter, so to speak, that's not so far away (6)
I believe the answer is:
closer
'not so far away' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for closer that I've seen before include "one concludes" , "Nearer or more penny-pinching" , "More airless; nearer" , "Nearer in time or space" , "More near or imminent" .)