The gPhoto2 Manual, From installation to development. Edited by Tim Waugh, Hans Ulrich Niedermann and Michael J. Rensing
All the libgphoto2 API generated from the source code by Doxygen. That documentation is also generated at build time if you have Doxygen installed. The documentation maybe incomplete. Code patches to supplement it are very welcome.
Answer all that you wanted to know about gphoto2.
Reverse engineered documentation on PTP/IP.
How to donate to the gphoto2 project.
We are collecting information on remote controllable cameras here.