Y.K. Optical

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Y.K. Optical was a small company based in Yokohama (Japan). It used the brand names Kobalux and Avenon for two wide-angle lenses. These were mainly sold in Leica screw mount, with an M-mount adapter offered as an option, but it seems that some of them were directly made in Leica M mount.[1] Kobalux seems to have been the predominant name in north America, and Avenon the only name within Japan. The lenses were also available under other names, such as Pasoptik,[2] Bower and Adorama, perhaps also Avenar.[3] The existence of a "Komura" name variant is probably a false rumour.[4]

The 28mm lens was introduced at the beginning of the 1980s by another small company, which was bought by Y.K. in the middle of the 1990s.[5] Production stopped in February 2002.[6]

Contents

Kobalux Wide 28/3.5

The Kobalux Wide 28/3.5, alias Avenon L 28/3.5, has six elements in four groups.[7] The first generation, released in 1982 or 1983, was sold in black or chrome finish and became multicoated in 1992 (some lenses are inscribed AVENON MC).[8] It has a round focusing tab and a six-blade diaphragm and focuses down to 1 metre.[9] The second generation, or "M-series", was sold in black with a silver rim. It has a crescent-shaped focusing tab, an eight-blade diaphragm, grip tabs on the aperture ring and it focuses down to 0.75m.[10]

The lens was supplied with two caps and a metal hood; an external brightline finder and an 28/90mm M-mount adapter were available separately.[11]

Kobalux Super Wide 21/2.8

The Kobalux Super Wide 21/2.8, alias Avenon L 21/2.8, has eight elements in six groups.[12] It was sold in chrome or black finish. The first generation, originally announced as a limited series, was released in 1994 or 1995.[13] The second generation appeared in 2000 as a millenium edition.[14] The third generation, or "M-series", has recomputed optics, an eight-blade diaphragm and focuses down to 0.75m.[15]

The lens was supplied with two caps, a metal hood, an external brightline finder and a 35/135mm M-mount adapter (the finder and mount adapter were also available separately).[16]

Notes

  1. See this post at photo.net, with a first-hand testimony of the existence of M-mount lenses.
  2. See a picture in this page at photo.net.
  3. This is reported in this page by Peter Lausch.
  4. See however this page by Frank Mechelhoff. This page of a Hong-Kong forum copies an erroneous earlier version of this very encyclopedia article.
  5. Post by FR in a Hong-Kong forum.
  6. See the 20 November 2002 web archive of the Kobalux website.
  7. Lens scheme in "Abenon no raika-maunto renzu". See also the table of Leica screw mount lenses by Matsumo.
  8. "Abenon no raika-maunto renzu" (saying 1983) and table of Leica screw mount lenses by Matsumo (saying 1983).
  9. "Abenon no raika-maunto renzu".
  10. Kobalux M-series 28mm f/3.5 in the Kobalux website, web archive dated 9 August 2002.
  11. Kobalux M-series 28mm f/3.5 in the Kobalux website, web archive dated 9 August 2002.
  12. Lens scheme in "Abenon no raika-maunto renzu". See also the table of Leica screw mount lenses by Matsumo.
  13. Announced as a limited series, 1994 date: table of Leica screw mount lenses by Matsumo. 1995: "Abenon no raika-maunto renzu" says 1995.
  14. table of Leica screw mount lenses by Matsumo.
  15. Kobalux M-series 21mm f/2.8 in the Kobalux website, web archive dated 9 August 2002.
  16. Kobalux M-series 21mm f/2.8 in the Kobalux website, web archive dated 9 August 2002.

Bibliography

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