I found this
Since I think libgpio uses direct port IO, you have to be root, or the
program needs suid root. In /usr/local/bin, do
chmod u+s gphoto2
for me (Gentoo) it was in /usr/bin.
this allowed non-root to use gphoto2 and access the camera:
gphoto2=model=USB PTP Class Camera
digikam is still not working though...
will post more if I find the problem with digikam