Before the development of microelectronics and electronic display devices, only optical viewfinders existed.
Direct optical viewfinders
Direct viewfinders are essentially miniature Galilean telescopes; the viewer’s eye was placed at the back, and the scene viewed through the viewfinder optics. A declining minority of point and shoot cameras use them. Parallax error results from the viewfinder being offset from the lens axis, to point above and usually to one side of the lens. The error varies with distance, being negligible for distant scenes, and very large for close-ups. Viewfinders often show lines to indicate the edge of the region which would be included in the photograph.
Some sophisticated 20th century cameras with direct viewfinders had coincidence (split-image) rangefinders, initially with separate windows from the viewfinder, later integrated with it; they were called rangefinder cameras. Cameras with interchangeable lenses had to indicate the field of view of each lens in the viewfinder; more usually, interchangeable viewfinders to match the lenses were used.