The Library of Congress has a comprehensive website detailing how to cite primary sources including photographs, films, cartoons and illustrations in APA format.
"Citing primary sources correctly is an important part of studying primary sources, for a number of reasons.
It is important--and ethically necessary--to provide full credit to the creators and publishers of documents, and to allow future scholars to find the source quickly and correctly. Citing a primary source is also crucial to critical thinking and analysis because it requires that the student think carefully about where the source came from, who made it, and in what context the student first discovered it.
Today, most students have access to primary sources through electronic means. The examples below serve as a guide to the most common formats and types available on the Library of Congress Web site." (loc.gov)