Understanding Leica M Series Lenses
Leica M series lenses fit Leica M System rangefinder cameras. These include the compact, full-frame digital rangefinder cameras as well as Leica M series 35mm cameras and all older M series cameras introduced in 1954. The Leica M lenses are great gear because of their quality and compact size.
Characteristics of Leica M Mount Lenses
Leica M rangefinder lenses are relatively small. An unusual aspect of these lenses is that you manually control them. There's a manual aperture ring for adjusting aperture and one for focusing. Although you set the aperture manually, aperture priory shooting is possible on most Leica rangefinder cameras. When focusing, a cam-operated mechanism in the base of the lens connects mechanically with the camera's rangefinder window mechanism. To focus, adjust the lens until the two superimposed images in the center of viewfinder merge.
About Leica M Series Lenses
There's a specific model type and name for each kind of lens, that depends on its maximum aperture and application. This nomenclature allows photographers to identify the right type of lens for their use. Elmar lenses have a maximum aperture between f/3.8 and f/4 and are extremely sharp. Leica Elmarit M lenses are a little faster, with an f/2.8 aperture. Leica Summilux M lenses are relatively low-cost lenses, with a maximum aperture of f/2.4. These are particularly light, and they're available in fixed focal lengths between 35mm and 90mm. The best lenses in terms of optical quality and performance are the Leica Summicron M lenses, which boast a maximum aperture of f/2. Choose the f/0.95 to f/1.25 Leica Noctilux M lenses for shooting in low-light conditions.
Leica Prime and Variable Lenses
M Series cameras use fixed focal length prime lenses. This is partly to ensure the highest optical quality, as well as for natural picture composition using the selectable frames visible in the viewfinders of rangefinder cameras. Separately available clip-on viewfinders cater to wide-angle lenses with a field of view wider than that offered by standard viewfinders. For similar reasons, Leica doesn't manufacture zoom lenses for rangefinder cameras, but instead offers Tri-Elmar lenses that have three selectable focal lengths. This type of lens construction avoids the inevitable loss of quality experienced with zoom lenses, as well as retaining full compatibility with Leica's optional universal wide-angle viewfinders.
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