On a digital camera
optical viewfinder is the eyepiece that you look through to frame and focus your subject before taking the picture. Because the optical viewfinder and your camera lens
are not positioned the same way (e.g. the viewfinder is located above the camera lens), you may notice your final image is not an exact duplicate of what you saw through the optical viewfinder. If the digital camera has an LCD
you can also use this to focus and frame the subject.