Subjects relating to press photographs (6)
I believe the answer is:
topics
'subjects' is the definition.
('topic' can be a synonym of 'subject')
'relating to press photographs' is the wordplay.
I cannot quite see how this works, but
'to' is found in the answer.
The remaining letters 'pics' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for topics that I've seen before include "Subjects about optics" , "Subjects to talk about" , "'Subjects, themes (6)'" , "'Matters dealt with, in conversation say (6)'" , "Things to talk about" .)