The Leica M3 is a 35 mm rangefinder camera by Ernst Leitz GmbH (now Leica Camera AG), introduced in 1954. It was a new starting point for Leitz, which until then had only produced screw-mount Leica cameras that were incremental improvements to its original Leica (Ur-Leica). The M3 introduced several features to the Leica, among them the combination of viewfinder and rangefinder in one bright window, like on the Contax II, a bayonet lens mount, and rapid film advance lever. It was the most successful model of the M series, with over 220,000 units sold by the time production of the M3 model ended in 1966. It was succeeded by a number of later film M series cameras, including the Leica M-A film camera in 2014. The earliest Leica M3 pre-model that was built, sold at auction in 2009 for €72,000. In June 2019 a pre series model from 1952/1953 was sold for €360.000 at the 34th Leitz auction in Wetzlar. Mount This new bayonet mount, which has not been changed in the following half century, is called the Leica M-mount. Lenses are changed faster than with a screw mount, and framelines set automatically. Non-Leitz/Leica bayonet-mount lenses can also be used (although none were produced in any quantity while the M3 was sold), and a simple adapter also allows the use of screwmount lenses (whether from Leitz or other companies). Viewfinder The M3 has an exceptionally bright viewfinder when compared to any previous or subsequent model, including the modern M9. The M3 has a high magnification factor of 0.92×, which is useful in critical focusing, and especially with long lenses (subsequent Leicas would use 0.85×, 0.72× or 0.58×). It was the first Leica to combine rangefinder and viewfinder into one window. (Other cameras, such as the Contax II, already had this feature before World War II; and other companies were making screwmount bodies with combined finders.) Framelines for 50, 90 and 135mm are shown, although none for any wider lenses. However, Leica solved this problem in two different ways: a separate viewfinder slid into the accessory shoe. the so-called Leica "Specs" or "glasses": These auxiliary lenses/prisms are put in front of the viewfinder and rangefinder windows for the 35mm focal length. The drawback of this attachment is that they reduce the famous brightness of the viewfinder. The Dual Range Summicron f/2 lens came with an auxiliary fitting similar to that