bright-line viewfinder

A bright-line viewfinder is a type of camera viewfinder that uses an optically projected rectangle to show the photographer the exact area of the subject that will be captured in the photograph. This system is essentially an inverted Galilean telescope and provides a view that is neither inverted nor reversed.1

Unlike some other viewfinder types, bright-line viewfinders do not suffer from parallax error when viewing distant subjects. However, for closer subjects, a slight parallax error can occur because the viewfinder and camera lens are not in the exact same position. This can lead to framing inaccuracies, where a subject that appears fully visible in the viewfinder might be partially cut off in the final image. Modern cameras often use electronic viewfinders or LCD screens, but the bright-line system remains a common optical viewfinder design.12