The Leica filters for the Leica M system are made of optically pure glass, are plane-parallel ground and carefully coated so that the performance of the Leica M lenses is fully maintained even with the filter attached. The range is deliberately limited to those filters that are most commonly used in photography.

The circular polarizing filter is used to eliminate annoying reflections on non-metallic surfaces and increases contrast as well as richer color reproduction.

Polarizing filters have the property of producing the same effect after every 180-degree rotation. The polarizing filter for the Leica M is therefore supplied with an adapter with a swivel mount, so that it can be swiveled 180 degrees in front of the viewfinder to assess and control its effect before taking the picture.