Kobalux

Kobalux (also marketed as Avenon, Pasoptik, or Bowers depending on the country) is the unsung hero of the modern rangefinder renaissance. In the 1990s, before Voigtländer flooded the market with affordable glass and long after Leica had stopped making screw-mount lenses, this small Japanese company appeared out of nowhere to keep the LTM dream alive.

Produced by Y.K. Optical in Yokohama, Kobalux lenses are prized today for being the "perfect compromise." They combine the compact, pancake form factor of vintage 1950s lenses with modern 1990s multi-coatings. For street photographers, the Kobalux 21mm f/2.8 remains one of the best-kept secrets in the system—a lens that rivals the Super-Angulon in size but costs a fraction of the price.

History

Kobalux's history is defined by an identity crisis.

The Name Game (1980s to 2002)

The lenses were manufactured by a small workshop in Yokohama called Y.K. Optical. Because they were a small OEM, they used different brand names for different distributors:

• Kobalux: The primary name used in Japan and by high-end exporters like Dante Stella.
• Avenon: The most common name found in Europe and parts of Asia.
• Pasoptik: A rare branding found in Germany.
• Bowers: Occasionally seen in the US market.
• The End: The company ceased production around 2002, just as the Cosina-Voigtländer revolution was taking off. In many ways, Kobalux proved there was a market for modern LTM lenses, paving the way for the Voigtländer Bessa system [[1]].

Product Lines (LTM Native)

Kobalux focused almost exclusively on compact wide-angle lenses. They are native LTM (Leica Thread Mount) but were designed in the modern era to be used on M-cameras via adapters.

The Kobalux / Avenon 21mm f/2.8

The brand's masterpiece.

• Design: A tiny, symmetrical wide-angle lens. It is barely thicker than a body cap.
• Performance: Unlike vintage 21mm lenses (which are often single-coated and flare-prone), the Kobalux features excellent modern multi-coatings. It delivers punchy, high-contrast images with very low distortion.
• Vignetting: Like the Leica Super-Angulon, it has significant light fall-off in the corners, which many users adore for the "classic wide" look.
• The Finder: It was almost always sold with a matching 21mm external viewfinder. While plastic, the finder is bright and accurate.

The Kobalux / Avenon 28mm f/3.5

A dedicated street photography pancake.

• Size: It is microscopically small. On a Leica M body, it makes the setup pocketable in a way few other lenses can.
• Optics: A simple 6-element design. It isn't a resolution monster like the Leica Elmarit-M ASPH, but it offers a pleasing, classic rendering with good contrast.
• Versions:
  • Standard: Black or Chrome finish.
  • "Millennium" Edition: A limited run (often in Avenon branding) featuring high-grade brass construction and special finishing [[2]].

Technical Specifications

Feature	Specification Details
Native Mount	LTM (Leica Thread Mount)
Focus Coupling	Coupled. (Standard rangefinder coupling).
Build Materials	Metal. The black versions are often anodized aluminum (lightweight), while silver versions are often chrome-on-brass (dense).
Aperture	Classic Layout. Click stops are usually distinct and mechanical.
Filter Thread	58mm (21mm f/2.8 - remarkably large for such a small lens) or 43mm (28mm f/3.5).
Markings	You may find the exact same lens engraved Kobalux, Avenon, or Pasoptik. They are internally identical.
Compatibility	Fully compatible with all M-mount bodies (with adapter). Unlike the old Super-Angulon, the rear element does not block the meter on the Leica M6 or M7.

Why Photographers Choose Kobalux

• Metering Compatibility: The classic Leica Super-Angulon 21mm f/3.4 cannot be used on an M6 because it blocks the light meter. The Kobalux 21mm f/2.8 solves this. It has the same vintage footprint but clears the meter, making it the perfect 21mm for the M6/MP shooter.
• The "Pancake" Factor: There are very few 21mm lenses that are this small. It allows you to carry an ultra-wide option in a coat pocket without it taking up space in your main bag.
• Value: While prices have risen, a Kobalux 21mm kit (with finder) is still generally cheaper than a Leica Elmarit 21mm, while offering a build quality that feels superior to many modern plastic options.

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Sources

• [1] Dante Stella (Kobalux/Avenon 21mm Profile): https://dantestella.com/technical/kobalux.html (The definitive internet resource on this brand).
• [2] CameraQuest (The Avenon 28mm): https://cameraquest.com/ave28.htm
• [3] 35mmc (Avenon 21mm Review): https://www.35mmc.com/18/06/2016/avenon-21mm-f2-8-review/