Menu Position MENU --> 
4 -->Finder / Monitor
What it Does Specifies how the camera switches between the EVF and the rear LCD
Recommended Setting Auto
Menu Position MENU --> 4 -->Finder / Monitor
What it Does Specifies how the camera switches between the EVF and the rear LCD
Recommended Setting Auto
There’s a short explanation and an accurate explanation of how this function works. I’ll start with the short explanation.
This function determines if the infrared sensor near the EVF should be used to automatically switch between the LCD and EVF. When set to AUTO, the rear LCD is always in use, unless something comes close to the IR sensor to the right of the viewfinder, in which case the EVF is invoked.
When set to VIEWFINDER, the rear LCD remains dark and the EVF will only turn on if the IR sensor above the viewfinder senses something proximate.
I set this feature to VIEWFINDER whenever I’m doing some time exposures or using the intervalometer and I don’t want to waste valuable battery power illuminating the rear LCD during the exposure. In this configuration battery power is only used for the display when I’m looking through the EVF.