I just gave the .deb's a go (v2.4.4-1) with my Canon EOS 40D. gphoto2 --auto-detect worked about 20% of the time, other times there was no camera found. --capture-image either said no camera, or once recorgnised the Canon, but gave an error (which I didn't note down). The N810 crashed after about 10 minutes of trying things. Note, that all calls to gphoto2 were within a script that enabled USB host mode first, and reverted to OTG mode at the end, yet I still had a crash