Mamiya CWP with 58mm f1.7 (M42)

[Smoli4]

#2


#3


#4

[caspert79]

How is this lens performing?

[Smoli4]

[caspert79]

Looks like a very fine lens.

[vivaldibow]

Looks nice. Yours is the M42 mount; mins is the Exakta mount. From the infinity mark, I looks like from different manufacturers. The M42 version is said to be radioactive.

[Smoli4]

[stevemark]

At least mechanically, your Mamiya 1.7/58mm is completely different from mine:

0) M42 vs Exakta bayonet
1) larger focusing grip than mine
2) focusing scales orange (feet) / white (Meter) instead of orange (feet) and green (m)
3) my lens (obviously the older one) has the typical Mamiya letters (look at the "f" in feet or the "m" for meter), yours has not ordinary letters
4) the aperture scale on your lens is linear (equal distances between the aperture stops); my lens has largely varying distances betweem the different aperture stops (indicating an older design)
5) your lens goes from f1.7 ... f16, mine from f1.7 ... f22
6) diaphragm on my lens is "semi-automatic" (you have to cock it manually after each image taken); yours probably is automatic (?)

I wonder whether both these lenses were made at Mamiya, or just one of these ...

[Smoli4]

[stevemark]

Thank you for your clarifications!

Since there are only two or three examples of the "Mamiya" SLR described in the internet, my camera (including its lens) might well be a pre-production model. The entire aperture mechanism of my lens seems a bit outdated for a 1960 camera. Minolta, for example, was switching to a "fully automatic" aperture system shortly after introducing the SR-2 (1958). Probably Mamiya was well aware of the need to have a fully automatic aperture for their first production SLRs.

S

[blotafton]

Nice rendering I like it.

[stevemark]

[KEO]

[Smoli4]

[Smoli4]

yeah

[aidaho]

[stevemark]

[casualcollector]

Way off topic. I that green object in image #2 a U-Boat?!

[Smoli4]

[KEO]

[eggboy]

This is an interesting thread...and I hope the following makes if MORE interesting.

I've literally just received a Japanese-market-only Pentamatic II with a Yashinon 5.8cm f1.7 lens. This camera/lens combo was only released in Japan for some reason...seems Yashica was flailing about at the time at the beginning of their SLR journey...eventually retreating a bit to lower market/lower specification M42 models...and the Pentamatics were caught in the carnage.

My new to me lens has light fungus, tight focus, and a weird automatic aperture that doesn't work...see the pics below...you can see it has 9 iris blades too, based on the number of pivot pins visible.

THIS 1.7 lens is different than the usual Pentamatic 5.5cm/1.8 lens, that also had a brief run as an M42 model to use up the remaining optical blocks before Yashica went to the Tomioka-sourced 5cm f2 that we (most of us...) know and love.

The current theory is that the weird 5.8cm/1.7 lens....was sourced from Zunow! It's internally different than the 5.5cm and later Tomioka designs.

See the following link that seem to support this:
http://yashicatlr.com/Pentamatic.html#zunow

This page is SUPER-well researched...read down to see the continuation of the lens on the first Exakta-mount Mamiya Prismat (and Sears Tower 32a)....perhaps Zunow, now reorganized as Ace Optical and out of the 35mm lens biz, sold the design/tooling to Mamiya or other lens constructor who updated the cosmetics and mount to M42 for these later versions?

I've seen the Zunow hypothesis in a few other places (Japanese-language sites translated with Google translate) about the 58/1.7 being, at the very least, a Zunow design, if not made by/subcontracted to, Zunow.

Here are two quick pics....literally just started working on this lens today ( 15 March 2023):

[Alun Thomas]

I've seen that information before, but I have to say I'm skeptical about the reasoning they used to establish any connection to Zunow.

Left out in the analysis is that the styling for the Pentamatic version of the 58/1.7 is extremely similar not only to the Mamiya versions of the 58/1.7, but in fact to all other Mamiya SLR lenses made in roughly the same period, including those made for Nikons Nikkorex F. The story loses plausibility if Mamiya also appropriates Zunows styling, but a quick look shows that isn't the case. Mamiyas styling (in terms of focus ring markings/colourings and other factors) was fairly constant across the Pentamatic lens, the lenses for both mount versions of the Prismat SLRs, the Argus camera, and the 35 and 135mm lenses supplied for the Nikkorex.

One other point made regards the use of an underlined 'o' for the serial 'No' prefixing, but this is by no means unique to Zunow lenses, even early Takumar lenses used that up until 1958-60 when they stopped. At that time it was common and a vast number of manufacturers used that, probably for no other reason than that everyone else was too. Then, they all stopped.

Another aspect is that the lens is not used or seen anywhere marked as a Zunow lens. Zunow supplied many lenses for many makers, but one constant factor is that they were all marked with their makers name. Zunow were not shy about letting the world know it was their lens, and in fact neither were camera manufacturers, it was probably a selling point. Not that many other lens makers had the cachet that Zunow did during that period, due to their large aperture rangefinder and slr lens designs.

None of this is to say the lens categorically was not a Zunow design, but it is to say that it's just a theory with next to no supporting evidence, with more evidence existing pointing in a much different direction (Mamiya). Mamiya had had an SLR in development since the early 1950s with several prototypes released, it's not known why it took them so long to release. They would also have developed at least a normal focal length lens during that time and probably had that ready for release. Going on the available evidence that's probably a more likely scenario, that they licenced it to Yashica for use while they prepared their own SLR for release.

Ultimately it can't be fully known, however one observation I'll make is of the existence of people who see certain things everywhere, whether or not they actually are there. Some people find a Tomioka made lens every time they lift up a rock, others Zunow, and I'm sure there's other examples.

[eggboy]

[KEO]