Kuribayashi Petri C.C. Orikkor 2/50

[leemik]

[edri]

Thanks for the info.

[D. P.]

[Oldhand]

[kds315*]

I, too, have that lens, shoulg dig it out I guess..

[wolfhansen]

Some first shots of the lens with my A7II & KECAY M42/E-Mount Helicoid


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[papasito]

Really very good pics.

IT's very rare thing that in your best 10 lenses thread, nobody puts this lens among those best ones.

For my eyes is by far more sharp than the helios 44 and with the same pleasent bokeh.

I don't know if the orikkor ones are the same 7 elements than the last bayonet Petri version without orikkor word ar the front ring.

[Mos6502]

Nice to see this thread still going. I haven't used mine in a while, but since I first posted, the M42 blog has done an interesting review of this lens: https://spiral-m42.blogspot.com/2017/05/petri-camera-co-high-speed-petri-part-3.html

I think I'm going to give mine some use next time I load up one of my M42 cameras.

[macheck]

Is this lens radioactive? the ad presented in this thread says it contains "rare earth"

[tomasg]

Very nice images, it reminds me a bit a MOG Domiron. Here is another nice link:

http://pakira3.sakura.ne.jp/wp/?p=77220

[Mos6502]

"Rare earth" describes a number of minerals, not all of which are radioactive. I don't know what glass Petri used though, but it could be any number minerals.

As for the link above, thanks! I think most of the Petri lenses give a rather Meyer-esque look, but this one in particular is a little more unique than most of them, I don't really know of another lens quite like it.

[macheck]

My question concerning radioactivity was for those who have this lens and are able to measure it.

[Mos6502]

Sorry for attempting to answer.

[macheck]

Mos6502 sorry, nothing personal, but this lens was produced for a short period of time and was more complicated than next model, it gives an assumption that it might be rad one, if you have one it would be nice to have a check.

[wolfhansen]

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[Mos6502]

Macheck, I do have this lens (I started this thread after all) but no way to measure if it is radioactive. I suspect that the reason for its complexity just has to do with the state of lens technology at the time. It is easy to forget that creating a fast 50 that would clear an SLR mirror was still a big deal in the 1950s, and very few actual 50mm lenses existed in speeds higher than f/2.8, most companies settling on a slightly longer focal length of 55 or 58mm. This lens was most likely designed in-house by Petri, and the "excess" complexity of the design is probably just the result of inexperience in producing this sort of lens, as Petri had never made an SLR, nor a lens for one, before. It should be noted that Nikon's original 2/50 for the F was also a seven element design, before it was revised, becoming a conventional six elements in four groups design. So even the big names had some trouble with this.


However, as seen above, Nikon's approach was a little less original than Petri's.

Wolfhansen, thank you for the photos! Nice examples of exaggerated OOF rendering of the Orikkor - it makes me think of how painters, imitating photographs, would render a background.

[papasito]

Summicron M 2/50 till 1969 had not any problem with the seven elements lenses.

The Nikon 2/50 remind me a bit of the Ultron/planar (Icarex/Rollei mounts)

[Macca]

Another aspect of the lens worth mentioning is that it is clearly not an f2 lens in terms of light gathering and displays the same shutter speeds as some f1.4 lenses! I need to test it against some of my others more "scientifically" but it`s very notable in general use.

[Alun Thomas]

The second generation of Petri lenses, the first to use the Petri mount, seems to have a 50/2 with the same layout, at least for the early models. (Those in the facebook group: Photography with Classic Lenses will already have seen posts regarding it, it has also been the subject of conjecture on Japanese Petri fan websites.)


In this photo I tried to get some reflections to show the similarity. The 3 bright and one small pinpoint light on the right hand side of the lens is the rear group, and the three pinpoint lights on the left are the forward group.


Lenses swapped sides when I wasn't looking....


The left hand element is from the Petri Auto, the right hand one is from the M42 Orikkor lens


Another attempt at photographing the reflections, not entirely successfully. The three bright point lights on the upper right of each lens are from the triple cemented element. There is then a less bright point light, on the right lens (Orikkor) it is to the left of the three larger reflections from my desk lamp. On the left lens the dimmer point light is discernable in the midst of the reflections from the desk lamp.

Oddly enough the Petri manual for the Penta V2 camera this lens came with (https://www.butkus.org/chinon/petri/petri_penta_v2/petri_penta_v2.htm) shows the lens as a more conventional 6/4 type. Perhaps they were, once they used all the elements they had made for the original Penta. But it makes for an interesting find, and a possibly even rarer lens. I have not been specifically looking for it, but in several years of ebay trawling have only come across two, and know of one other belonging to a member of the facebook group mentioned.

[Blazer0ne]

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[Alun Thomas]

Most likely yes, although admittedly I did not try, as I was concerned greatly with not getting them mixed up.

[kds315*]

[Blazer0ne]

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[Alun Thomas]

I went back and unscrewed the rear groups. They are not interchangeable the thread sizes are ever so slightly different. I then removed the triple cemented elements - they are the same dimensionally and can be each fitted into the carrier for the other lens.


The Orikkor group is on the left. It is slightly different and has an extra ring screwd onto the main carrier, a small graduated anti-reflective baffle, which the later lens does not have.



Orikkor on the left again. More differences here, the smooth part at the top is not flat black more of a metallic dark brown. Also has a groove around the diameter the later lens does not have.

The later auto aperture lens is five bladed, with somewhat rounded blades.

My copy of the auto lens has a serial 56527. The lens belonging to the other facebook group member was earlier, in the 52000s.

A couple of links to the Japanese fan site where the possibility of the 7/4 structure is discussed:
https://translate.google.com/translate?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=ja&sp=nmt4&tl=en&u=https://w.atwiki.jp/petri/pages/64.html
https://translate.google.com/translate?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=ja&sp=nmt4&tl=en&u=https://w.atwiki.jp/petri/pages/224.html

[Blazer0ne]

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