i was able to use my canon 6d camera as a webcam.
what i did is basically, connected the camera via mini usb, then:
modprobe v4l2loopback exclusive_caps=1 max_buffers=2
gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt yuv420p -s 1280x720 -threads 2 -f v4l2 /dev/video4
this switched camera to video mode, i guess, or at least something happened, the mirror went up, it creates /dev/video4 which i was able to use from OBS and Jitsi meet.
now, the question is: is it bad for the camera?
i understand it is not officially supported by the canon software.
there is an official software that turns eos 6d mk ii in to web cam for windows and macos. i don’t know if something in hw prevents usage of 6d the first version.
also, if i just shoot video, it has a time limit, i guess 30 minutes, and it shuts down. probably to prevent overheating.
but when i connected it via usb, and used gphoto2+ffmpeg, i could use it as webcam for long time.
and i wouldn’t say it got particularly hot. though i don’t know, it is not easily measurable.
so the question is, do you think i can damage the camera by doing this?
one guess: may be i am getting live view with that. but live view is always disabled on my camera. may be gphoto activates it.
as i understand if i connect via hdmi, i get the numbers in the picture: https://www.youtube.com/watch?v=m02pdlb-Rxs
that is why this camera is not used as webcam usually.
other guess, i have read people can connect it to the computer via USB and use EOS Utility under windows/macos to make remote shooting.
then probably i get live view with this.
is it dangerous to keep the camera in live view for long time?
what can i damage: sensor? other circuits?