One of the things I like about my Panasonic Lumix GH4 is the fact that the EVF display reflects my settings for ISO, aperture and shutter speed. I like to think of this as WYSIWIG mode (what you see is what you get). There was just one problem—it was only working that way when shooting video. When shooting stills the display was always about right regardless of how over or underexposed my settings might have been. Similarly, the histogram always showed the dynamic range to be more or less centered. It was never totally pushed to the left or right like you would expect if the settings were way off.
After repeatedly searching through all the menus I finally discovered the problem. My setting for Constant Preview was OFF. Switching it to ON made the EVF reflect the combination of exposure settings as I expect. Similarly, the histogram will now go off the chart if the exposure is wrong.
It’s nice to have the option to choose which behavior you prefer. However, I can’t think why Panasonic decided to call this feature Constant Preview. I think WYSIWIG mode is more apt. And I’m not sure why this is only an option for stills and not for video. But it’s fine with me since this is the behavior I prefer anyway.