The Leica Universal Wide-Angle Viewfinder M is a shoe-mounted external viewfinder for M-system rangefinder cameras (including M8). This viewfinder offers bright-line frames to match the 16-18-21mm lens. Since the 1.33x conversion factor has to be considered for the M8 digital camera, bright-lines for 21, 24, and 28mm are also included. It can also be used with other fixed lenses that match this range. A parallax compensation dial allows for adjustment of the frame to the focusing distance, in five steps (0.5, 0.7, 1, 2 meter & infinity).

The use of one aspherical lens element and one with achromatic correction in the viewfinder makes it insensitive to stray light, and provides a high resolution and exceptional brilliance image.