Automatic exposure on Nikon

    Reposting from https://github.com/jim-easterbrook/python-gphoto2/discussions/149

    It's not clear to me, and testing did not yield any obvious results, so I will ask:

    What mode a camera must be so I can change the f_number but let the
camera compensate with exposure time? I have a Nikon D7200 and when I try
to automatically take photos at different f_numbers, no matter what mode
the camera is (P, A, S or M), the exposure time is always the same
(whatever was last used in the camera).

    Cheers,

	-- Marcos.