Kuribayashi/Kyoei 35 mm f/3.5  

Petri film SLR cameras from the 1960s with M42 lens mounts were often equipped with lenses marked Petri Kuribayashi or Petri Orikkor (sometimes misspelled Orrikor in eBay ads). The 35 mm f/3.5 of this series, in particular, has been discovered for UV photography by Steve Smeed (MFlenses bulletin board, ClubSnap forum) and shown (e.g. by Klaus Schmitt, Photography of the Invisible World blog) to exhibit a higher transmission in the near UV than the Noflexar 35 mm, and a useful transmission down to 320-330 nm. Mounted on a focusing helicoid for use in the macrophotography range on a Micro 4/3 camera, this lens exhibits excellent properties in UV photography, including a high image quality at apertures between f/8 and f/16. These lenses were also branded as Kyoei and other brands (see below).

Figure 1. Kyoei type 1

In the above picture is a very early Acall Kyoei 35 mm f/3.5. Judging from its serial number 35001, where the first two digits may well be the focal length (a practice used in the past by several lens makers including Nikon, and on the Novoflex Noflexar 35 mm f/3.5) it may be the very first specimen that left the factory with the Acall Kyoei brand and in this version. The front element diameter of this lens is 23 mm. This specimen is equipped with a fixed, non-standard 46 mm threaded mount and a removable Exakta adapter. An externally quite similar barrel style was used by Kyoei for lenses mounted on some Petri 35 mm rangefinder cameras from the 1950s and early 1960s. I call this lens Kyoei type 1 in the rest of this discussion.

Kyoei Optical Co. Ltd. is the company, while W. Acall (where W stands for wideangle) seems to be a series or sub-brand (like Nikon's Nikkor and Minolta's Rokkor). However, in some cases (especially on lens shades and cardboard lens boxes) Acall is the only visible branding. The Super Acall branding is also found on other lenses.

Figure 2. Kyoei type 2

So far, I have been unable to obtain any Petri Kuribayashi branded lenses. However, the very same lens design was used in lenses with different brands and/or mounted in different barrels and lens mounts, including M42 and Exakta, and marketed in the same period. The Acall and/or Kyoei branding is common. Above is a W Acall Kyoei (which I call Kyoei type 2) in a barrel identical to the Petri Kuribayashi/Orikkor, except for a small detail - the focus ring is all black instead of "zebra" style. The serial number of this Kyoei type 2 is 36843. I have seen pictures of a Kyoei type 2 specimen marked 35722, which suggest that the original serial numbering of the Kyoei type 1 was inherited by the type 2 until it reached 35999, after which it restarted at 36XXX. Therefore, these type 2 lenses with the "Kuribayashi look" were introduced after the Kyoei type 1. The newer preset and aperture rings are narrower and more protruding, perhaps to make them easier to feel without looking, or to turn with gloves.

The brands used on these lenses are quite varied. The following list includes the brands carried by lenses of these types.

  • Petri Kuribayashi
  • Kuribayashi Orikkor
  • Petri Orikkor
  • Petri Kyoei
  • Acall Kyoei
  • W. Acall Kyoei

It is necessary to add to the above list also the W-Komura 35 mm f/3.5 lens in M39 mount. There is a disagreement among Internet sources as to whether this lens was made by Kyoei, but the picture at this link and several others on the Internet of the same lens model branded W. Acall Kyoei leave no reasonable doubt. In fact, Kyoei-branded specimens of this lens model seem to outnumber the Komura ones. In addition, some of the mechanical details, like the retaining rings of the front element, of the W-Komura 35 mm are the same as in the Kyoei type 2. This lens may also be branded Accura and Telesar.

Kyoei also marketed the type 2 lens in an M39/L39 (Leica rangefinder) mount, in a barrel different than the Komura discussed above.

All lenses on this list are known to be good for UV photography, or are externally identical to lenses that have been tested and found to be good. They all have a front element diameter (as exposed at the lens front) of approximately 23 mm. The filter mount of all specimens I have been able to inspect is 46 mm. All specimens I have seen have a golden colored coating of the front element (not bluish). The last of these features is an important telling sign, since the type of lens coating is a major factor in the UV performance of a lens. The older EL Nikkor series, also usable in the UV and slightly better for this application that the newer N series, also displays golden front elements.

Figure 3. Partly disassembled Kyoei type 2

These lenses have a relatively simple but solid mechanical construction (Figure 3). All optical elements can be exposed and removed from their mounts for thorough cleaning if necessary, with minimal needs to use tools. The diaphragm blades are rather shiny, a fact that may lower contrast in extreme illumination conditions. No lubricant is used in the aperture mechanism, except possibly to dampen the external aperture ring itself. A moderate capillary spreading of lubricant can be observed on some inner parts of the barrel, but is unlikely to cause trouble and is easily cleaned after partial disassembly of the lens.

These lenses were probably produced in the 1960s and possibly early 1970s. See also the Optomax 35 mm f/3.5, which seems to be a rebranded almost-clone. Many 35 mm f/3.5 lenses of other brands were likely produced by Kyoei, including several models (albeit not all) officially branded Soligor and Photax. Given the large number of lens models with slightly different mechanical designs, optical coatings and brand names, it seems Kyoei went wild with small style changes over a span of a few years, providing their customer companies with many slightly different variations on the same basic design. I do not know which company made subsequent models of 35 mm f/3.5 lenses with wider front elements, also commonly available on the second-hand market.

The UV performance of these Kyoei type 1 and 2 lenses is discussed more in detail here.


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