You disable the sensor that switches the exposure display from the rear screen to the OVF when you bring your eye up to the OVF. Except, there is no specific setting that disables it by name.
Use this setting to tell the camera to not use the rear screen for exposure display. This will save you a lot of battery life. The MILC body “behave” like a DSLR, which means use must look through the viewfinder in order to see the exposure and AF point display. However, you can enable/disable exposure display on the rear screen any time you wich by pressing [INFO].
To repeat, you want to minimize the use of the rear display as much as possible, which can help extend your battery life. If you are using your camera and macro lens in a controlled indoor environment, then you may want to consider using a Canon AC/DC adapter.
The AC/DC adapter actually comes in two parts. There is the 120 VAC to DC converter, which is used with just about all camera bodies. And then there is the battery eliminator, which is a module that is the same size and shape as your camera’s battery. The battery eliminator needed can vary from one camera to the next, depending upon what battery your camera uses.
