Leica Summilux-M 21mm f/1.4 ASPH.

Leica Summilux-M 21mm f/1.4 ASPH.

When it appeared, the Summilux-M 21mm f/1.4 ASPH. stood out as the fastest wide-angle lens ever offered for the Leica M system, pairing an ultra-wide angle of view with an f/1.4 maximum aperture that almost no other rangefinder lens of this focal length had matched [1][2]. The order number 11647 identifies the standard black anodized production lens, which Leica has kept in the catalogue since 2008 [2]. For collectors and photographers, its appeal rests on this unusual combination of speed and coverage in a relatively compact M-mount body, along with the rendering character that comes from a fast aspherical wide-angle design [1].

Optically the lens uses ten elements in eight groups, with a floating element that maintains image quality across the focusing range down to its 0.7 m close limit [2][3]. Leica describes the design as strongly correcting vignetting and distortion, and the floating group is intended to hold quality at close distances [3]. The aperture runs from f/1.4 to f/16 and is set manually with click stops including half values, and the diaphragm uses eleven blades [2]. The barrel is built from anodized aluminium and optical glass, focuses by hand, and couples to the rangefinder; rather than a conventional threaded front filter, it accepts Series VIII filters mounted within its dedicated rectangular hood [2][3]. The lens carries a six-bit code (101111) so digital M bodies can recognise it, even though it is read optically rather than being a routine user setting [2].

There are no widely documented optical variants of this lens; it has been produced as a single black anodized version under model number 11647 throughout its run, with the engraving SUMMILUX-M 1:1.4/21 ASPH [2]. Listed weight is about 580 g and the barrel measures roughly 66 mm long and about 70 mm in diameter, extending further with the hood fitted [2]. Because the front filter system is the in-hood Series VIII type rather than a screw-in thread, buyers should treat the correct hood (Leica part 12461) and the matching external finder as part of a complete outfit [2].

Optical qualities

Rendering This lens is generally described as favouring character over clinical uniformity. Reviewers note a soft glow wide open at f/1.4 that gradually gives way to higher sharpness as the lens is stopped down, with strong central sharpness reached around the middle apertures while corners retain some of the softer look [4].

Sharpness At f/1.4 the centre shows a soft, glowing quality rather than crisp detail; sharpness builds as the aperture closes, with notable improvement by roughly f/2.4, though the extreme corners remain comparatively soft even stopped down [4].

Contrast and color Color rendering is reported as pleasing and reasonably accurate across most apertures, with the wide-open glow lending images a softer, dreamier look when shooting near maximum aperture [4].

Bokeh and transitions Out-of-focus highlights take on a variety of shapes rather than uniformly round discs, a trait reviewers attribute partly to residual aberration; the result is described as distinctive and varied rather than perfectly smooth [4].

Flare resistance Flare behaviour is varied and easy to provoke, especially with the hood removed, producing effects ranging from soft streaks to ghosting and arc-shaped patterns depending on light angle [4].

Distortion and vignetting Leica states the design strongly suppresses vignetting and distortion, and reviewers describe barrel distortion as very difficult to detect in normal use [3][4].

Aberrations Some residual aberration remains; in demanding subjects such as point light sources it can prevent perfectly circular rendering, which also contributes to the lens's varied bokeh shapes [4].

History

Development and Launch The Summilux-M 21mm f/1.4 ASPH. was introduced in 2008 as the fastest wide-angle lens in the M lineup, extending the Summilux name to an ultra-wide focal length [1][2]. It was positioned as a high-end, specialist optic for photographers wanting both very wide coverage and an exceptionally large aperture on the M system [3].

Production Evolution The lens has remained in production as a single black anodized configuration under order number 11647, without widely documented optical or finish revisions [2]. Collector serial-number records place early examples from around 2008 onward, with substantial numbers assigned in the following years [2].

Special editions No major factory special editions or alternative finishes of this lens are widely documented; it is generally encountered only in its standard black anodized form [2].

Collector Notes Because the filter system is the in-hood Series VIII type rather than a screw-in front thread, buyers should confirm that the correct rectangular hood (part 12461), front cap, and an appropriate external bright-line finder (such as 12024 or 12025) are present, since these accessories are integral to using the lens and costly to replace [2]. Confirm that the six-bit coding and engraving (SUMMILUX-M 1:1.4/21 ASPH.) match a genuine 11647 example, and check the front element and floating-group barrel for haze, fungus, or impact damage as with any large, complex wide-angle [2][3].

Sources

• [1] Leica Camera. Summilux-M 21 f/1.4 ASPH. (product description). https://leica-camera.com/en-US/photography/lenses/m/summilux-m-21mm-f1-4-asph-black
• [2] Leica Wiki (English). 21mm f/1.4 ASPH Summilux-M. https://wiki.l-camera-forum.com/leica-wiki.en/index.php/21mm_f/1.4_ASPH_Summilux-M
• [3] Leica Camera. Summilux-M 21 f/1.4 ASPH. (design and floating element). https://leica-camera.com/en-US/photography/lenses/m/summilux-m-21mm-f1-4-asph-black
• [4] Hillary Grigonis, The Phoblographer. A Tempting Mix of Unusual Bokeh: Leica 21mm F1.4 Summilux Review. https://www.thephoblographer.com/2021/05/24/leica-21mm-f1-4-summilux-asph-review/