List of options at the core of camera manual (4)
I believe the answer is:
menu
'list of options' is the definition.
(I've seen this in another clue)
'at the core of camera manual' is the wordplay.
'at' says to put letters next to each other.
'the core of' indicates the central letters.
'manual' becomes 'nu' (I can't justify this - if you can you should believe this answer much more).
The middle of 'camera' is 'me'.
'me' put next to 'nu' is 'MENU'.
Can you help me to learn more?
(Other definitions for menu that I've seen before include "restaurant guide" , "Food programme of restaurant" , "choice of food" , "Range of dishes available" , "List of options" .)