说法正确

photo by是意思是有某人拍摄的照片

举例：

Photo by Russell Lee. Prints and Photographs Division, Library of congress.

国会图书馆打印与复印部。

Image credit: Left, photo courtesy of the author; right, photo by Stephen voss.

图片来源：左为作者自拍照；右为斯蒂芬·沃斯拍摄。