K.O.L. and Sun lenses in Leica screw mount
The Japanese company Gojō Kōki Seisakusho began making lenses during World War II for the Nippon Leica copy. Lenses in Leica screw mount were continued after 1945 by the company Sun Kōki, until well into the 1950s.
Contents
5cm lenses
K.O.L. Xebec, Sun Xebec and Sun Sophia 5cm f/2
Gojō Kōki Seisakusho made the K.O.L. Xebec 5cm f/2 six-element collapsible lens for the Nippon Leica copy.[1] The lens barrel is copied from that of the Leitz Summar. The focusing ring is graduated in metres and has a tab with an infinity stop.
Two main versions of the barrel are known. The "first" barrel has the infinity stop at 10 o'clock (as seen from the front), the word Mtr in small characters and depth-of-field indications for apertures from 2 to 9.[2] Its finish seems quite poor, according to the pictures and to the comments of Mori Ryōsuke.[3] The "second" barrel has the infinity stop at 7 o'clock, the word mtr in larger characters, depth-of-field indications from 2 to 12.5, and a seemingly better finish.[4] The aperture ring is graduated from 2 to 9 on at least some lenses, even those with the second barrel.[5] The lens barrel was probably gradually improved, and the repartition of the first and second barrels do not follow the serial numbers.
The lens rim is black and has the engraving K.O.L. Xebec N°xxxxx F=5cm 1:2 on all the examples observed so far. The earliest known lens reportedly has no.34688; it is said that it was originally not rangefinder-coupled, and that a coupling cam was added to it later.[6] Other lenses have numbers in the 66xxx, 70xxx, 75xxx and 77xxx ranges.[7]
The lens was renamed Sun Xebec 5cm f/2, certainly when Gojō became Sun Kōki after 1945. A single example is known, with no.77818.[8] It has the second barrel, and its aperture scale goes from 2 to 12.5. The engraving on the front rim reads Sun Xebec on one side and 1:2 f=5cm No.xxxxx on the other.
The Sun Sophia 5cm f/2 was certainly an evolution of the Sun Xebec. A single example is known, with no.72715.[9] The barrel has some similarity to the second barrel found on the Xebec, but it looks heavier and more recent. (The lower serial number is unexplained.) The front element is more recessed than on the Xebec, and the optical design was perhaps altered. The front rim is engraved Sophia on one side and 1:2 f=5cm Sun No,xxxxx on the other.
7.3cm and 7.5cm lenses
Prominar 7.5cm f/3.5 and 7.3cm f/3.5
The Prominar 7.5cm f/3.5 and 7.3cm f/3.5 are something of a mystery. The Prominar brand was used by the Kowa company for camera lenses from 1954, and reportedly from the second half of the 1940s on projection lenses (see Kowa). It was not the first use of this brand name, and a Prominar Anastigmat 10.5cm f/4.5 lens is found c.1937 on the Reex, a Japanese folding camera.
The Prominar 7.5cm and 7.3cm lenses observed in Leica screw mount have almost the same barrel as the Sun Sola with similar focal lengths (see below). It is patterned after the early Leitz Elmar 9cm f/4, and has a black and chrome finish. The only chrome plated part is the long focusing ring, covered with very fine mills. The distance scale is engraved in metres and goes down to 1.25m and perhaps closer. The aperture scale is inscribed on the fixed part of the barrel, in front of the diaphragm ring, from 3.5 to 12.5, and depth-of-field indications are given for the same aperture range. The lenses look uncoated from the available pictures. The 7.5cm and 7.3cm only differ by the engraving, which merely reads Prominar F=7.5cm 1:3.5 N°xxxxx or Prominar F=7.3cm 1:3.5 N°xxxxx.
The known numbers are 71963 on a 7.5cm lens, and 72022 on a 7.3cm, just before the 72xxx numbers found on the Sola. All these converging evidences certainly indicate that these Prominar lenses were made by the same company as the K.O.L. and Sun lenses, perhaps in the immediate postwar period, before it reorganized as Sun Kōki.
Sun Sola 7.5cm f/3.5 and 7.3cm f/3.5
The Sun Sola 7.5cm f/3.5 and 7.3cm f/3.5 have almost the same barrel as described above for the Prominar. More pictures are available, showing a distance scale going down to 1m or closer, and the same mtr indication as on the Sun Xebec 5cm f/2. The aperture scale has the same range, from 3.5 to 12.5, but is now inscribed directly on the diaphragm ring.
Early 7.5cm lenses with a black and chrome finish are known with numbers in the 723xx range.[10] The colour pattern is different from the Prominar: the chrome parts are the base of the barrel and the rear portion of the focusing ring, and the rest is black. The front marking is Sun Sola F=7.5cm 1:3.5 N°xxxxx.
Later lenses have an all chrome finish. The front marking is Sun Sola f=7,5cm 1:3,5 No,xxxxx on lens no.72458,[11] and Sun Sola f=7,3cm 1:3,5 No,xxxxx on lens no.72471,[12] showing minor variations coming at a fast pace.
From the available numbers, it appears that these Prominar and Sola 7.5cm and 7.3cm lenses was made in very small quantity, perhaps less than 500 units.
9cm lenses
Sun Xebec Telephoto and Sun Sola 9cm f/4
The black and chrome Sun Xebec Telephoto 9cm f/4 is known from a single example, with number 54337.[13] It has a black and chrome barrel and a knurled focusing ring. The chrome parts are the aperture ring, the bottom part of the focusing ring and the lens mount. The base of the lens is surrounded by a leatherette strip. The word Japan is engraved on the black part of the focusing ring. The distance scale is engraved in feet, apparently down to 3.5ft. The aperture ring is engraved in the international scale, apparently to 16, and depth-of-field indications are given for all the aperture range from 4 to 16. The front rim is black and is engraved SUN OPT. Xebec TELEPHOTO 1:4 f=9cm xxxxx with some triangular mark between the focal length and the serial number.
To be continued
13.5cm lenses
Sun Telephoto 13.5cm f/3.8, rangefinder coupled
The Sun Telephoto 13.5cm f/3.8 exists in a rangefinder coupled version, directly attached to the camera mount. This lens is less common than the Sun Sola 9cm f/4, and the only number known so far is in the 154xx range.[14]
This lens has an all chrome barrel, quite similar to that of the early Sun Sola 9cm f/4, with a tripod attachment at the bottom. The lens head rotates when focusing. The focus ring is quite long and has fine mills in its middle part. It has a distance scale engraved in feet at the rear, perhaps down to 5ft, and the mention Made in Japan towards the front. The aperture ring is immediately to the front. It has two aperture scales graduated from 3.5 to 22, one on each side, whose indexes are on the focus ring. The lens name, features and serial number are inscribed on the side, around the lens rim.
Sun Telephoto 13.5cm f/3.8, for reflex housing
The Sun Telephoto 13.5cm f/3.8 also exists in a short barrel version for a reflex housing, again with 39mm screw mount but with no rangefinder coupling. Its film-to-flange register fits the Accura reflex housing, and certainly also the Leitz PLOOT and Visoflex, and the Kilfitt Kilarscope reflex housings.
The example pictured below has a serial number in the 3xxxx range. Its barrel seems to be made of aluminium or light alloy. The various rings tend to discolour in a somewhat uneven way, perhaps because different alloys were used for the various parts. The focus ring is knurled, and the distance scale is again engraved in feet. The aperture ring has a scale on each side. The name, features and serial number are inscribed at the front, and there are two milled rows further to the front.
  
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| Sun Telephoto 13.5cm f/3.8 short barrel lens on an Accura III reflex housing, alone and with a Leotax S. Pictures by David Murphy. (Image rights) |
Sun Telephoto 13.5cm f/3.5
To be continued
Notes
- ↑ Six elements: advertisement for K.O.L. lenses reproduced in Inoue, p.132, and in Hagiya, p.179 of Sekai no Raika renzu. Made by Gojō: "Kokusan shashinki no genjōchōsa" ("Inquiry into Japanese cameras"), lens item Ja1; Shirai, p.23.
- ↑ First barrel visible on lens no.34688 pictured in Mori, p.101, and on lens no.70067 pictured in HPR, p.260.
- ↑ Mori, p.100.
- ↑ Second barrel visible on lens no.66429 pictured in HPR, pp.258–9, and on the Sun Xebec no.77808 pictured in Mori, p.101.
- ↑ Aperture ring from 2 to 9 confirmed on lens no.34688 (first barrel) pictured in Mori, p.101, and on lens no.66429 (second barrel) pictured in HPR, pp.258–9.
- ↑ Mori, p.100. This lens is pictured and tried on pp.101–3 of the same source, and one of the pictures is reproduced in this page of Akiyama Michio's Red Book Nikkor.
- ↑ Lens numbers reported in Mori, p.97. No.66429 is pictured in HPR, pp.258–9, on the rangefinder Nippon no.14. No.70067 is pictured in HPR, p.260, on the viewfinder Nippon no.1.810010.
- ↑ Lens reported and pictured in Mori, pp.94 and 100–1, pictured and sketched in Shirai, pp.17–8 and 20 (on the rangefinder Nippon no.23001).
- ↑ Lens pictured in HPR, pp.263–4, on the Nicca Peerless Type-3 no.24001.
- ↑ Examples no.72350 and 72381, observed in online auctions or offered by dealers.
- ↑ Example no.72458, sold at auction on February 8, 2008.
- ↑ Example no.72471, sold as lot no.351 of Westlicht auction no.12 (November 17, 2007).
- ↑ Lens offered for sale by a dealer.
- ↑ Example offered for sale by a dealer.
Bibliography
- Hagiya Takeshi (萩谷剛). "Raika to sekai no Raika-yō renzu" (ライカと世界のライカ用レンズ, Leica and other Leica-mount lenses). In Sekai no Raika renzu (世界のライカレンズ, Leica lenses of the world) Part 1. Tokyo: Shashinkogyo Syuppan-sha, 2003. ISBN 4-87956-061-8. Pp.178–88.
- HPR. Leica Copies. London: Classic Collection Publications, 1994. ISBN 1-874485-05-4. Pp.258–60, 263–4 and 413.
- Inoue, Mitsuo (井上光朗). "Shashin renzu no yoake. Renzu-ya Funsenki" (写真レンズの夜明け・レンズ屋奮戦記, Dawn of the photographic lens – Fierce war tales between lens shops). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no.14, October 1989. No ISBN number. Rikō kamera no subete (リコーカメラのすべて, special issue on Ricoh). Pp.128–132. (Contains a reproduction of an advertisement listing the K.O.L. Xebec, same as in Hagiya's article, and information on the Gojō company.)
- "Kokusan shashinki no genjōchōsa" (国産写真機ノ現状調査, Inquiry into Japanese cameras), listing Japanese camera production as of April 1943. Reproduced in Supuringu kamera de ikou: Zen 69 kishu no shōkai to tsukaikata (スプリングカメラでいこう: 全69機種の紹介と使い方, Let's try spring cameras: Presentation and use of 69 machines). Tokyo: Shashinkogyo Syuppan-sha, 2004. ISBN 4-87956-072-3. Pp.180–7. Lens item Ja1.
- Mori Ryōsuke (森亮資). "Sensō ga unda raika kopī-ki 'Nippon'" (戦争が生んだライカ・コピー機「ニッポン(Nippon)」, The 'Nippon' Leica copy, created by the war). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no.58, March 2001. ISBN 4-257-13032-6. Tokushū: Raika bukku '01 Raika kenkyū (特集:ライカブック'01・ライカ研究, Leica book '01: Leica research). Pp.94–103.
- Shirai Tatsuo (白井達男). "Nippon Camera" (ニッポンカメラ). Pp.17–26 of Maboroshi no kamera o otte (幻のカメラを追って, Pursuing phantom cameras). Gendai Kamera Shinsho (現代カメラ新書). Tokyo: Asahi Sonorama, 1982. ISBN 4-257-08077-9. (First published in Kamera Rebyū / Camera Review. no.2, February 1978.)
Links
In English:
- Past sales by Westlicht:
- K.O.L. Xebec 5cm f/2 and (Sun) Xebec 9cm f/4 on a viewfinder Nippon: lot no.312 of auction no.8 (November 27, 2005)
- Sun Sola 7.3cm f/3.5: lot no.351 of auction no.12 (November 17, 2007)
- Sun Sola 9cm f/4: lot no.352 of auction no.12 (November 17, 2007)
- Prominar 7.3cm f/3.5: lot no.282 of auction no.13 (June 7, 2008)
- Past sales by LP Foto:
- Sun Sola 9cm f/4: lot no.303 of auction no.16 (September 8, 2002)
- Sun Telephoto 13.5cm f/3.5: lot no.452 of auction no.31 (November 2, 2008)
- Sun Telephoto 13.5cm f/3.5: lot no.354 of auction no.8 (January 24, 2009) by Rahn
- February 8, 2008 auction by Hammer Down Auction Services at proxibid.com:
- Sun Sola 9cm f/4, lot no.286
- Sun Sola 7.5cm f/3.5, lot no.287
In Japanese:
- Kōgaku Seiki's Nippon camera at Akiyama Michio's Red Book Nikkor, showing a picture of the K.O.L. Xebec and Sun Xebec 5cm f/2 reproduced from Mori's article
- Sun Sola 9cm f/4 in the camera page at Field Cameraman Note
