Conversation so far:
Was photography a hobby or a career for Eakins?
Photography was a staple of Eakins' career as an artist as he is credited with: “having introduced the camera to the American art studio.“
What did Eakins typically photograph?
Eakins performed his own independent motion studies, also usually involving the nude figure, and even developed his own technique for capturing movement on film.
Did Eakins paint the things he photographed?
After Eakins obtained a camera in 1880, several paintings, such as Mending the Net (1881) and Arcadia (1883), are known to be derived at least in part from his photographs

Question: What else did he use the photographs for?
Self-contained rewrite: What else did Eakins use the photographs for besides paintings?