Leica Summitar 5cm f/2

Leica Summitar 5cm f/2

The Summitar marked a clear step beyond the lens it replaced, the Summar, by adopting a larger and more complex front group to control light falloff and improve coverage. Its optical layout uses seven elements in four groups, an unusually rich count for a normal lens of its era, when most rival 50mm f/2 designs for rangefinder cameras stopped at six elements [1]. Leitz positioned it as its highest-performance standard lens from its 1939 introduction until the Summicron arrived in the early 1950s, and it was promoted as particularly well suited to the emerging demands of color photography [1].

Built in chrome-plated brass, the Summitar is a collapsible screw-mount (LTM) lens that retracts into the camera body for a very compact package, then twists and pulls out to its working position [3]. It is rangefinder coupled and focuses to one meter, with a long focus throw of close to 180 degrees that lends precise control [2]. The aperture is clickless, since detented stops were not introduced on the normal Leica 50 until the Summicron, and on early examples the engraved scale follows a non-standard sequence reading roughly f/2, 2.2, 3.2, 4.5, 6.3, 9 and 12.5, which can briefly confuse photographers used to modern full stops [2][3]. With a screw-to-bayonet adapter the lens mounts and couples on later M cameras, although owners should note that collapsing it fully into some thin-bodied digital M cameras can risk contact with internal components [1].

Two production traits help identify and date a given lens. Examples made before the war are uncoated, while lenses from about 1946 carry a single blue coating on the optics [1][2]. The diaphragm originally used ten blades, and around 1950 Leitz switched to a six-blade assembly, reportedly using up earlier Summar-type parts, so blade count is a useful clue to vintage [1]. The front element is made from relatively soft glass that scratches easily, which is why many surviving lenses show cleaning marks [2].

Optical qualities

Rendering The Summitar is known for strong central sharpness with softer corners by modern standards, a balance typical of late-1930s computation that prioritized the center of the frame [1]. Wide open it shows a gentle, detailed softness that firms up by roughly f/3.5 to f/4, and stopping down improves edge performance though corners can still trail the center, an effect more visible on digital sensors than on film [3]. The ten-blade aperture of early examples produces a smooth, painterly out-of-focus rendering, and some users describe a degree of background swirl at wide apertures, while others find the swirl modest; reports of dramatic swirl are not consistent [2][3]. Coated examples can give surprisingly clean, even modern-looking contrast when in good condition, whereas hazy or uncoated lenses are more prone to veiling flare [3].

History

Development and Launch The Summitar was introduced in 1939 as the successor to the Summar 50mm f/2, which had been Leitz's flagship fast normal lens through the 1930s [1]. The redesign enlarged the front optics relative to the Summar to reduce mechanical vignetting and light falloff, and replaced the Summar's single front element with a cemented pair, changes Leitz tied to the growing interest in color film [1]. It remained the company's top normal lens until the Summicron 50mm f/2 superseded it in the early 1950s [1].

Production Evolution Production ran from 1939 into the mid-1950s [2]. Lenses were uncoated before the war and single-coated from about 1946 [1][2]. The diaphragm began with ten blades and changed to a six-blade design around 1950 [1]. The barrel shares much of its handling and construction character with the first-generation Summicron that followed, reflecting the continuity in Leitz's screw-mount lens line [2].

Collector Notes When evaluating a Summitar, the most common points to check are the condition of the soft front element, which is easily scratched and frequently shows cleaning marks, and the smoothness of the clickless aperture, which can develop play with age [2][3]. Whether a lens is coated or uncoated, and whether it has the ten-blade or six-blade diaphragm, both affect identification, dating and rendering, so these are worth confirming [1][2]. Period accessories that suit the lens include screw-mount hoods and the E36 filter fitting, and a screw-to-M adapter is needed for use on M bodies [1].

Sources

• [1] Ken Rockwell. LEICA SUMMITAR 50mm f/2 (1939-1953). https://www.kenrockwell.com/leica/50mm-f2-summitar.htm
• [2] 50mmF2. Leica Summitar 50mm f2 LTM Lens Review. https://50mmf2.com/writings/leica-summitar-50mm-f2-ltm-lens-review
• [3] Calibre Magazine. The Leica Summitar 5cm Lens. https://calibremag.com/the-leica-summitar-5cm-lens/