Help

I have a Canon 6d. in any of the shutter aperture priority modes when I try to add or subtract exposure using the rear thumb circle the camerea will not respond. I get a "L" in the shutter speed display briefly. I've tried "clear all camera settings"
For example I am trying to over expose a backlit subject and the camera will not respond with the rear thumb wheel.

If you are seeing "L" then it means the camera is locked. I'm not familiar with the 6D, but most Canon cameras have a three-position on/off switch with the 3rd position being 'on but locked'. Move that switch to full on.

Thanks, of course it was something simple.