Rangefinder camera

As camera and lens technology developed and wide aperture lenses became more common range-finder cameras were introduced to make focussing more precise. The range finder had two separated viewfinder windows one of which was linked to the focusing mechanisms and moved right or left as the focussing ring was turned. The two separate images were brought together on a ground glass viewing screen. When vertical lines in the object being photographed met exactly in the combined image, the object was in focus. A normal composition viewfinder was also provided.