Leica Elmarit-M 21mm f/2.8 ASPH.

Leica Elmarit-M 21mm f/2.8 ASPH.

When Leica introduced this lens in 1997 it replaced the long-running non-aspherical 21mm f/2.8 Elmarit-M, bringing an aspherical surface and a reworked optical layout to the company's fast ultrawide for the M system [1][2]. The design uses nine elements in seven groups, and Leica chose a retrofocus configuration so that the rear cell would clear the metering systems of more recent M bodies, a decision that shapes much of the lens's character [1][3]. It is a compact, modern wide-angle that for years sat at the wider end of the M lineup alongside the 24mm and 28mm Elmarits.

The lens is fully rangefinder coupled and focuses to 0.7 m, with an eight-blade diaphragm offering click stops including half values from f/2.8 to f/16 [1]. It takes E55 screw-in filters in an internal thread, and because only the focus and aperture rings move, polarizers and graduated filters are straightforward to orient [1][3]. Reviewers describe the focus action as smooth and well damped, with a focus tab that makes the lens quick to use, though at 21mm the depth of field is so generous that precise rangefinder focusing is rarely critical [3]. A 21mm accessory viewfinder is needed for framing on film bodies, since the M finder does not show that angle of view. The body is a short barrel roughly 46 mm long and 58 mm in diameter, and Leica offered both a black anodized aluminium version and a chrome-plated brass silver version, the silver finish being the heavier of the two [1].

Across its run the optical formula remained the aspherical nine-element design, with the main documented variations being finish and the matching order numbers: 11135 for black and 11897 for silver [1]. The Leica Wiki records production from 1997 to roughly 2010 with several thousand lenses made, the black version dominating later batches [1]. The lens is not factory six-bit coded, although later black examples and user conversions are sometimes coded for use on digital M bodies; the lens predates the coding system that arrived with the M8. It was eventually succeeded in the catalogue by the smaller Super-Elmar-M 21mm f/3.4 ASPH [4].

Optical qualities

Rendering The Elmarit-M 21mm f/2.8 ASPH. renders with high contrast and the corrected drawing expected of an aspherical Leica wide-angle, but its retrofocus layout introduces compromises uncommon in symmetrical rangefinder ultrawides [3]. Documented behavior from a detailed user review is summarized below.

Sharpness The lens is consistently sharp in the centre at all apertures. The corners are softer wide open at f/2.8, improve at f/4, and reach their best around f/5.6 [3].

Distortion Because the optics were designed as a retrofocus type to clear camera metering, the lens shows some visible distortion, with the central portion of the frame tending to bulge slightly outward rather than the near-zero distortion typical of symmetrical rangefinder wides [3].

Distortion and vignetting Falloff is present at f/2.8 and is easy to see on plain surfaces such as blank walls, but it diminishes on stopping down and is generally not intrusive on real subjects; as with most ultrawide rangefinder lenses, some corner darkening never disappears entirely [3].

Flare resistance Flare control is generally good. Strong point light sources aimed into the lens at night can produce ghosting opposite the source if pushed, but in ordinary use this is not a problem [3].

History

Development and Launch The aspherical Elmarit-M replaced the earlier 21mm f/2.8 Elmarit-M (order number 11134), an eight-element, six-group design built from 1980 to 1997 in non-rangefinder-coupled and later rangefinder-coupled forms [2]. The 1997 redesign added an aspherical surface and moved to a nine-element, seven-group formula, and Leica adopted a retrofocus arrangement so the rear group would sit clear of in-camera metering cells [1][3].

Production Evolution The optical design was carried unchanged through the production run, with variation confined to finish and barrel materials: black anodized aluminium against chrome-plated brass for the silver version [1]. Leica Wiki serial-number tables document batches from 1997 onward, with the black version produced in the largest numbers in the later years [1]. The lens was not factory six-bit coded, predating the coding scheme introduced for digital M cameras.

Special editions No widely documented factory special editions of this lens exist beyond the standard black and silver finishes carrying order numbers 11135 and 11897 [1].

Collector Notes The barrel is engraved LEICA ELMARIT-M 1:2.8/21 ASPH. E55 with the serial number [1]. Buyers should confirm whether a black example has been six-bit coded if intended for digital use, since the lens left the factory uncoded and some have been added later. The silver chrome-brass version is noticeably heavier than the black aluminium one, which helps confirm the finish, and the matching 21mm viewfinder is a worthwhile accessory to locate for film use [1][3]. As with any used wide-angle, check the aspherical front area and internal elements for haze, cleaning marks, or coating wear before buying.

Sources

• [1] Leica Wiki (English). 21mm f/2.8 ASPH Elmarit-M. https://wiki.l-camera-forum.com/leica-wiki.en/index.php/21mm_f/2.8_ASPH_Elmarit-M
• [2] Leica Wiki (English). 21mm f/2.8 Elmarit M. https://wiki.l-camera-forum.com/leica-wiki.en/index.php/21mm_f/2.8_Elmarit_M
• [3] Ken Rockwell. LEICA 21mm f/2.8 ELMARIT-M ASPH Review. https://www.kenrockwell.com/leica/21mm-f28-asph.htm
• [4] Leica Camera. Super-Elmar-M 21 f/3.4 ASPH. https://leica-camera.com/en-US/photography/lenses/m/super-elmar-m-21mm-f3-4-asph-black