Petri (Kyoei) 8/500 rare lens

[luisalegria]

I have been looking for this lens for about a year and a half, and I finally found it on ebay. Luckily it went for cheap -







Besides some cosmetic wear and a couple of small fungus spots, its in good shape. Its missing the tripod mount setscrew, a minor issue.

This is one of those preset lenses made by Kyoei, a small lens manufacturer, for Kuribayashi about 1958-1960 as the first set of accessories for the first Kuribayashi Petri SLR, the Petri Penta (or Flex, depending on the market). The Petri Penta had an M42 mount, unlike the bayonet mount cameras that quickly replaced it in the Kuribayashi petri product line.

These were all lenses that were also sold under the Kyoei "Acall" house brand, as well as some other distributors. Under any brand, Kyoei lenses are quite scarce and even rare.

The 500mm seems to be one of those that are harder to find. This lens was illustrated in the original Petri Penta users manual, and is listed in the ihagee.org lens list as an Acall, so it should exist under these two brands at least.

Fit and finish is typical of Kyoei, quite high quality, but there was some effort at reducing weight on this one so it feels less solid than other Kyoei products. Also like other Kyoeis, the hood is exceptionally fine, very large and deep indeed, as it should be.

It is, like many other long focal length lenses of the time, not a telephoto. It has a cemented doublet in front and, also fairly common, an optical flat near the mount, probably to keep dust and moisture out. The advantages of this design are that it is easier to design a sharp lens (emphasizing center sharpness) and maximize contrast/reduce flare. The disadvantage, of course, is that one ends up with a very long lens. And this is indeed a very long lens. I heard many interesting comments while out shooting !

Like many other lenses of this type, the focusing helical is near the mount, a good place to put it from the point of view of reducing weight as the diameter can be narrow. However, it puts it behind the point of balance, making hand-holding quite difficult if not impossible. So to use this I had to do that most terrible thing, carry a tripod. Oh well, needs must. Minimum focus is what one can expect for this sort of lens, 30ft/9.7 m (note that decimal meters are marked, which seems a bit eccentric).

Performance is excellent. This is a very sharp lens wide open (by my standards at least). There is no CA problem, as is common with other long lenses of the time. For a 500mm f/8 it is quite easy to focus and hit the target zone. This is now my best lens >400mm, and the best I have tried in this category. It is even quite competitive with my Komura 400mm (though much harder to use). Kyoei was a high-quality manufacturer and it shows.

Unfortunately I forgot to bring along an extension ring. All at f/8





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[mo]

What a beauty and simply stunning, stunning results.It was worth the wait.....did it come up to what you were expecting as in performance?

[Scheimpflug]

[CarbonR]

Nice performance for a simple doublet