The best approach to setting critical focus is to use a tape measure or an external monitor. One menu category is devoted to setting up what will be displayed in the viewfinder. Everything from aspect ratio to shutter speed can appear. However, to set exposure you must rely on the camera's two independent zebra settings or rely on an external monitor or light meter. Exposure Considerations Underexposure is easily corrected.
Overexposure is final.
If the IRE level goes above 100, clipping will eliminate any detail in the image. The camera and recording format preserve enough information in the black gamma to shoot with maximum levels set at 90IRE and later expand the gamma in post to reproduce the image you imagined. They made the adjustments under controlled conditions in their test facility and stored them for us. That gives us three latitude settings-normal, extended knee, and extended toe. It was helpful because we were going to shoot outdoors with only a 9-inch monitor for reference.