Photo Credits or Photo Credit?

[kota]

Even for only one photo, do we use the plural form?

Usually when photos are published, the photographer is given recognition at the end of each caption to identify the source. Should it be: Photo credits: John Kelly, or Photo credit: John Kelly?

 

[Egmont]

Photo credit. The same if there are several photos, but each photo has its own credit line.

 

[JustKate]

Credit means "the person the photo who shot or provided the photo," so if there's one person (and there's almost always just one person), it's "Photo credit."

The only time I can think of that you might use "Photo credits" is if you have one place on a page or in a publication where you list the photograhers for several different photos. So for example, on a page displaying several photos you might write:
"Photo credits: John Kelly, June Bug and Roman Nome." You wouldn't usually do it this way, though, since normally each photographer ought to get specific credit for the photos he provided.