說法正確

photo by是意思是有某人拍攝的照片

舉例：

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

國會圖書館打印與復印部。

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

圖片來源：左為作者自拍照；右為斯蒂芬·沃斯拍攝。