This shoe-mounted viewfinder allows for comfortable viewing when using the 15mm ZM lens on the Zeiss Ikon camera.
The Zeiss Ikon camera viewfinder is designed to be used with lenses of focal lengths 28 mm, 35 mm, 50 mm and 85 mm. When using shorter focal length lenses a dedicated viewfinder for framing has to be attached to the accessory shoe on top of the camera. Focusing of the lens is to be made by using the camera range finder.