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EOS 6D auto ISO not changing or being set correctly

New Contributor

I haven't used my camera for a few months now but just today after wanting to use it, I'm noticing that the auto ISO setting is not working as I would expect it to anymore. In every mode I have the auto ISO set and have changed all sorts of combinations that would make the shot underexposed but the ISO gets set to 100 in every instance. For example in a somewhat dimly lit room I've set the camera to aperature priority at f/4 with auto ISO. Focusing sets the shutter to 1/1000 and ISO to 100, which makes for a completely black shot. Similiarly, I used shutter priority at 1/200 and focusing sets the aperature to f/10 and ISO of 100. Shooting through LV works fine though, however, I know shooting using LV vs VF works differently so I take that with a grain of salt.


I've checked my settings for the auto ISO and it's all default settings, and I even just reset all the settings to make sure. This essentially makes most of my shots underexposted unless I put it in manual mode and adjust the shutter and aperature appropriately, even with it set to auto ISO since it will default to 100. One thing I have noticed is that sometimes when adjusting/setting the auto ISO, the camera will pick the correct one, but then very quickly change back to 100. I've also turned off ALO and HTP and that has done nothing. I am also using the newest firmware. It's almost as if the camera's light sensor is overly senstitive, thinking that what it sees is going to be overexposed, thus setting the ISO way too low.


I suppose that was another thing I should have mentioned. In the manual tests, in the first shot (auto ISO), the Ev scale showed +2 before I took it, and in the second shot (manual ISO), it showed +4.

Which further suggests the meter is not functioning and hence why it is adjusting the auto ISO so low to try and compensate for the "overexposure".