Keep both eyes open when looking through the rangefinder
This has a few advantages. When shooting portraits, your subjects will be able to ‘connect’ with you by seeing one of your eyes. Without this, many subjects can feel a little bit uneasy like you’re hiding behind the camera.Secondly, keeping both eyes open lets you monitor what’s out of the frame so you can predict when your subject will enter the frame. This is important for capturing sports, animals, or any kind of action shots.