Hi again!
I’m guessing photographers are users. The problem is that you are using an old version of the plugin (4.0) which does not support search in users yet. The current version (4.6) however does.
If you want, you can update your plugin to the newest version by following this guide. Please follow it carefully to make the transition smooth.
After that, you will be able to see a new option panel on the General Options -> User search, where you can activate searching for users (photographers).