The EOS 5D Mark IV features the ability to have either an auto monitor brightness or a manual brightness. While in many situations it is preferable to manually set the LCD brightness and then adjust it to suit the conditions, sometime auto brightness works well. If you are looking at an image on the screen and the brightness seems to go up and down while looking, check where you right thumb is sitting – to the lower left of the Quick Control Dial (large dial on the back of the camera) there is a small, round light sensor. If you are covering this with your thumb, or any part of your hand, the brightness will change as you move your hand around. Either keep the sensor clear, or switch to a manual LCD brightness setting to stop this happen.
- EOS 5D Mark IV