Dear user,
I have a nikon FM3a which I tried the longest shutter release in low light with aperture priority (AE) setting.
I set the aperture at 22 and shoot a black canvas in dark room.
The exposure is taking up to 4 minutes.
Is this normal for FM3a? because when i check the manual, the longest exposure is only 8 second in AE mode.

Can anyone have any clue or suggestion toward this matter?

Thank you