There are a few things to check all related to the camera. If you are shooting in Aperture Priority, Shutter Priority, or Program mode, exposure won’t change unless you change exposure compensation. When in Manual mode, the exposure should change based off your settings. If you are not seeing this updated in the Case Air or on the back of your camera, the issue is your camera. For Canon cameras, make sure “Exposure Simulation” is on. For some Nikons, there is a setting called “Exposure Preview.” Please refer to your camera manual to determine if your camera has this setting and how to turn it on.
Please note that many cameras will not do exposure previews in movie shooting mode. This is a limitation of the camera, not the Case Air. This includes but is not limited to the Nikon D800 and D810.