One of the attractions of using an Electronic Viewfinder (EVF) instead of an Optical Viewfinder, typically found on most DSLRs, is that ‘What You See Is What You Get’ (WYSIWYG).
If you change the aperture you get a live view of the changing effects of depth of field and if you use the Exposure Compensation dial you will see if you are about to underexpose or overexpose the final image.
Although this Live View Display is usually what you want to see most of the time, there is one instance when this is NOT what you want to see. When working in a Studio with Flash off-camera the camera does not know about the flash that is about to light up the scene. So when you drop the ISO to 100 and close the aperture to f/11 what you see through the EVF is close to total darkness.
The solution is to go to the Menu > Custom Settings > Live View display (usually the third tab along on the Mark II A7 models) and turn the Live View Display Setting Effect to OFF
This Live View display is automatically switched off in the following instances
- When you mount a flash to the hot shoe and turn the Flash on
- When you select Bulb Mode in the shutter speed settings
- When use use a pop-up flash (not applicable to A7 users).