1 ACCEPTED SOLUTION
@annhackler wrote:The problem only happens inside. And it only happens when the flash is supposed to be working--to compensate I have been shooting either in "sports" or with the "flash off" setting inside. Diver hank suggested that the problem might be that I had moved the ISO to a fixed setting from auto and he is right, I did do that. I've moved the ISO back to auto, so I'll see if that solves the problem. But I more often than not shoot in Intelligent Scene Auto--so there is no option on the ISO---and the problem remains. It seems that about every third shot is dark.
As others have suggested, there is a high possibility that you are under the flickering effect of the LED lights. Luckily the T6i has the "Anti-Flickering" option so you should activate that. While there is no guarantee that it will fix the problem, it will 1. lessen it and 2. it will tell you that there's a flickering problem (FLICKER! is shown on the viewfinder).
Wow...there is not enough data in your description to do more than hazarding a guess but I'll do it anyways. Since you described that everything used to work fine and now sometimes the pictures are too dark and sometimes perfect and your flash is also acting up...like buzzing and flashing in burst...
What mode are you shooting with? Is it the green square or P when you mentioned Auto?
My wild guess would be that somehow you have inadvertently set your ISO from Auto to a fixed setting. The camera sets itself to the correct lighting conditions by varying 3 things: speed, aperture and ISO. With Auto ISO, the camera will auto adjust to the varying conditions using all 3 things and for something modern like a T6i, it can handle most of the lighting conditions. If you set the ISO to a fixed value...the auto mode can only adjust 2 things: the speed and aperture to a certain values and the camera would literally runs out of light without being able to vary the ISO. That might explain why sometimes your pictures are too dark and then OK (depending on available light). When the camera runs out of light. one problem would be trying to focus by using the flash as the focus assist...
First thing you should check is to see the ISO is not set to Auto. As I said, this is a wild guess.
@annhackler wrote:The problem only happens inside. And it only happens when the flash is supposed to be working--to compensate I have been shooting either in "sports" or with the "flash off" setting inside. Diver hank suggested that the problem might be that I had moved the ISO to a fixed setting from auto and he is right, I did do that. I've moved the ISO back to auto, so I'll see if that solves the problem. But I more often than not shoot in Intelligent Scene Auto--so there is no option on the ISO---and the problem remains. It seems that about every third shot is dark.
As others have suggested, there is a high possibility that you are under the flickering effect of the LED lights. Luckily the T6i has the "Anti-Flickering" option so you should activate that. While there is no guarantee that it will fix the problem, it will 1. lessen it and 2. it will tell you that there's a flickering problem (FLICKER! is shown on the viewfinder).
