Type of film only showing in visible and ultraviolet light? (4)
I believe the answer is:
noir
'type of film' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
(Other definitions for noir that I've seen before include "(Of film or fiction) with bleak settings and cynical characters" , "Film featuring bleak settings and cynical characters" , "cinematic style" , "type of film" , "Kind of dark film" .)