Kobalux Avenon 21mm f/2.8

Kobalux Avenon 21mm f/2.8

Despite a name that sounds European, the Kobalux Avenon 21mm f/2.8 is a Japanese super-wide lens built in small numbers by Y.K. Optical, a tiny workshop based in Yokohama [1]. The same optic reached the market under several brand names: Kobalux was the predominant label in North America, Avenon was the name used in Japan, and it also appeared as Pasoptik, Bower and Adorama, among others [1][2]. The firm's founder and chief designer, a Mr. Abe, had earlier worked on the well-regarded Komura lenses at Sankyō Kōki, and the Avenon name is understood to derive from his own [1]. The lenses were assembled in low quantities, and some examples lack a serial number because Abe reportedly died before they could be stamped [1].

Optically the lens uses eight elements arranged in six groups in a symmetrical, fully multicoated design, with a 58 mm filter thread and an eight-bladed diaphragm in the version recorded here [1]. It was built primarily for the Leica 39 mm screw mount, with a bayonet adapter supplied so it could be used on M-mount bodies [1]. Published material from the maker notes that the screw-mount fitting works across Leica M39 and M bodies as well as the Minolta CLE, Konica Hexar RF, Cosina Voigtländer Bessa series and former Soviet M39 cameras [1]. In the chrome finish the barrel is compact and light at roughly 225 grams, and the lens was typically sold together with a matching 21 mm brightline viewfinder, a metal shade, caps and the M adapter [1].

Several generations exist and matter to collectors. The first generation, announced as a limited series, was released around 1994 or 1995; a second generation followed in 2000 as a millennium edition; and a later "M-series" carried recomputed optics, an eight-blade diaphragm and closer focusing to 0.75 m [2]. The lens was sold in both chrome and black finishes, and most silver examples are reported to have silver faces, with all-black examples being less common [1]. Y.K. Optical is reported to have ended production in early 2002 [1].

Optical qualities

Rendering The Avenon 21mm f/2.8 is a multicoated, symmetrical wide-angle design, a layout commonly associated with even field illumination and restrained distortion in lenses of this type [1]. Contemporary reviews cited by collectors were favorable, describing it as a capable performer across its aperture range that could stand comparison with established 21 mm rangefinder optics of the era [1]. Detailed, independently measured optical data is limited, so specific claims about its corner sharpness, vignetting or behavior on digital sensors should be treated with caution.

History

Development and Launch The lens originated with Y.K. Optical of Yokohama, a small Japanese maker led by Mr. Abe, who had earlier been associated with the Komura lenses produced by Sankyō Kōki [1]. It was offered mainly in Leica screw mount with an optional M-mount adapter, though some examples appear to have been made directly in Leica M mount [1]. The first generation reached the market around 1994 or 1995, initially as a limited series [2].

Production Evolution Production passed through distinct phases. A second generation appeared in 2000 as a millennium edition, and a subsequent "M-series" introduced recomputed optics, an eight-blade diaphragm and a minimum focusing distance of 0.75 m [2]. Across these phases the lens was produced in both chrome and black finishes [1]. Production is reported to have ceased in early 2002 [1].

Collector Notes Buyers should be aware that some examples were never serial-numbered, reportedly because the designer died before they were stamped, so the absence of a serial number is not in itself a sign of a problem [1]. Finish details help with identification: silver-finished lenses commonly have silver faces, while all-black versions are scarcer [1]. The matching 21 mm brightline finder, metal shade, caps and the LTM-to-M adapter were original accessories and are worth confirming as present and correct on a used example [1]. One point of caution for prose and listings: some published descriptions call the lens rangefinder coupled, but coupling behavior is not consistent across bodies and adapters, so compatibility should be checked for the specific camera in use [1].

Sources

• [1] Japan Camera Hunter. Camera Geekery: Avenon 21mm f2.8. https://www.japancamerahunter.com/2021/03/camera-geekery-avenon-21mm-f2-8/
• [2] Camerapedia. Y.K. Optical. https://camerapedia.fandom.com/wiki/Y.K._Optical