Picture oddly smeary in viewfinder (9)
I believe the answer is:
canvasser
'viewfinder' is the definition.
'picture oddly smeary' is the wordplay.
'picture' becomes 'canvas' (canvas is a kind of picture).
'oddly' indicates alternate letters.
The alternate letters of 'smeary' are 'ser'.
'canvas'+'ser'='CANVASSER'
'in' is the link.
(Other definitions for canvasser that I've seen before include "collector of views" , "One soliciting votes" , "employed during an election" , "Seeker of opinions" , "Petitioner who seeks sales or votes" .)