Type of photography US magazine used by mistake? (4-5)
I believe the answer is:
time-lapse
'type of photography' is the definition.
(I've seen this in another clue)
'us magazine used by mistake?' is the wordplay.
'us magazine' becomes 'time' (US weekly magazine).
'used by' says to put letters next to each other.
'mistake?' becomes 'lapse' (lapse is a kind of mistake).
'time'+'lapse'='TIME-LAPSE'
(Other definitions for time-lapse that I've seen before include "Kind of cinematic technique for showing a slow process at an accelerated pace" , "Photography technique" , "Photographic technique to show very slow processes in motion" .)