Thank you for the info.
But how can I choose a gphoto driver? The INDI server panel at the start of Astroberry offers a drop-downl-list with pre-configured INDILIB drivers.
And the only choice there is the "Canon DSLR driver"...

How can I figure out which driver gphoto2 is using??? When I try to take an image with gphoto2 the shutter is released, but no image is stored and the camera
hangs and displays "busy...".