Changelog in Gphoto2 indicates support of Theta ShutterSpeed in 2.5.10
But after some tests
Gphoto2 2.5.23 (fresh compilation) on raspbian + Theta V => shutterSpeed (on video mode, i.e. shutter is less than a second) is not working (no real change after a set-config)
Maybe it’s work on other cameras.For now, ptpcam still needed for shutterspeed configuration in USB