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Chinon and Tomioka?
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PostPosted: Fri Oct 18, 2013 9:10 am    Post subject: Reply with quote

Fujinonuser wrote:
Again, the Cosinon Tomioka 1.2 / 55mm lens was totally made by Tomioka.

The Porst Color Reflex MC Auto 1.4 / 55mm M42 with the characteristic "window" in the aperture ring is just as sharp and has the same high definition as the Chinon Tomioka 1.4 / 55mm. If you compare the color histograms for both lenses, though, you will notice a difference in color transmission. This has been noted before and there are illustrations around. One may ask how many optical plants had the tools and the capacities for such high-quality lenses. If you look at the Porst 1.4 / 55mm sideways, it very much reminds me of an early Zeiss or Rollei Planar. There are also Chinon 1:1.4 55mm multi-coated lenses with diamond marker that were manufactured according to the Tomioka design.

The Porst 1.4 / 55mm lenses must be clearly distinguished from Chinon 1.4 / 50mm PK lenses, which are also very sharp, but shorter, and use radioactive lens elements that tend to yellow. They were apparently made by Cosina.


Agree about Cosinon Tomioka M42 1.2/55mm. At the time COSINA didn't know how to make such lenses. COSINA took much from Tomioka. As case of 1.4/55mm, at first they built body only and inserted Tomioka optical block. Completely flat rear optical block is identical among many lenses (Rikenons excluded). It's easy to adjust coating properties and reflection during production to differentiate brands. Later COSINA made whole lens. PK series for sure.

When you mention PK 1.4/50mm: I believe you're wrong when contributing CHINON to COSINA: differences are even bigger then with M42. CHINONS continue the smoothest focusing grease from MC M42 1.4/55mm CHINONS. They kept completely flat rear. Whereas clumsier PK COSINA body doesn't. Please check this comparison: http://forum.mflenses.com/pentax-pk-bayonet-1-4-50mm-alternatives-chinon-cosina-ricoh-t60018,start,15.html

Who made CHINON PK 1.4/50mm if not CHINON himself? Please give me alternative i have none.


PostPosted: Fri Oct 18, 2013 9:14 am    Post subject: Reply with quote

I firmly would like to remind everybody here to

a) stay close to the topic and
b) refrain from impolite language.

Thank you!


PostPosted: Fri Oct 18, 2013 11:57 am    Post subject: Reply with quote

Pancolart wrote:
Who made CHINON PK 1.4/50mm if not CHINON himself? Please give me alternative i have none.


When this topic was discussed before, it was established that Chinon didn't make their own lenses. Due to the common use of the word Chinon, good luck finding the former discussion with a search. Sad

There were over 20 optical companies in Japan, so there are surely several alternatives.

My apologies if this point has already been made, but I still think it bears re-iterating: with brands like Chinon, we are almost certainly looking at glass from different sources put into barrels from a common source. Maybe Cosina made all the barrels (it was a prime part of their business) and the glass came from a variety of sources. That would explain why there are some good lenses and some bad lenses that share similar barrel stylings, it would also explain why there are Tomioka lenses that look like Cosina and Chinon ones but differ in performance and inner details.

This barrel style with the twin thin chrome bands is very common:



Chinon and Tomioka lenses often appear with this barrel style, but it's also seen with many other brandings such as Prinzflex, Optomax, Super Travenar, Mirage, Kestrel etc; therefore I think it's reasonable to assume that there was a foundry producing these barrels in vast quantity and supplying them to many companies. There is a wide range of qualities of glass to be found in these barrels, from really poor to rather good. The engravings on these barrels vary a lot too, but the physical style remains constant.


PostPosted: Sun Oct 20, 2013 10:34 am    Post subject: Reply with quote

Let's take to the record that Tomioka -- at least with the 1.2 / 55mm lens -- manufactured a lens that was sold as a Cosinon.

Many of the tubes with leatherette grip and double silver ring seem to have been manufactured by Chinon who have never been attributed as having operated a glass foundry. Other light-weight tubes with very thin letters seem to have been manufactured by Cosina. Strangeley enough they look similar to the Yashinon tubes. All full metal tubes with knurled grip seem to have been made by Cosina. The tubes with the window in the aperture ring seem to have been made by Cosina.

As to the Porst and Revuenon 1.4 / 55mm multicoated lenses I repeat that they have left the factory as sharp as the older Tomioka lenses. It has been noted and shown in a sample pic here that some of these lenses have a green front element whereas most have a purple or rather magenta front coating. This reminds me of the Porst Ozunon lenses for the Fujica FX bayonet. They also have a green front element.

The color tansmission of the older Tomioka lenses is different from the newer multicoated Tomioka lenses. I will insert here two histograms for comparision that had been posted to the internet. I'm not the copyright holder nor have I made these histograms, but you may easily comfirm these histograms if you own both lenses (the copyright holder is kindly asked to contact me and ask to withdraw these pictures or post a link to the original URL that unfortunately I have lost).

Older Tomioka Rikenon lens (there are differences between Chinon Tomioka and some Rikenon Tomioka as we know):

Multicoated Yashinon Porst lens:


PostPosted: Sun Oct 20, 2013 10:42 am    Post subject: Reply with quote

As to the glass used, we must definitely distinguish between 55mm and 50mm lenses. The 1.4 / 50mm lens is a completely different design with different glass and different coatings.

The Chinon (and Agfa) multicoated 1.4 / 50mm PK lens is a very sharp lens, although the copies that I have tried have a radioactive lens element that tends to yellow with age. I have not compared it to a Cosinon 1.4 / 50mm (if there is such a lens), but I would venture to guess that the Chinon is Cosina-made. The Chinon serial number characteristically starts with the letter "C".

Please mind that only the very early Cosinon lenses, that were designed by Cosina themselves, have a bad reputation. Since 1973 or so, their capacity to produce excellent lenses has improved dramatically. At a time, they manufactured many lenses sold as Tokina, Soligor, Vivitar and others. They now have a high-priced section of digital lenses under the licenced Voigtländer brand.


PostPosted: Sun Oct 20, 2013 11:04 am    Post subject: Reply with quote

As to the question who manufactured (some !) of the Rikenon 1.4 / 55mm lenses in Tomioka design, we are open to guess work as we do not have printed sources like in all other Tomioka cases.

I would guess that the Rikenon 1.4 / 55mm M42 lenses with flat rear element have optical glass furnished by Tomioka. I may be wrong but I had the personal impression that these Rikenon lenses had a greater black share in their colors, that is to say, their colors did not look as bright as those taken with a Tomioka lens in the same light setting, but that may also result from a different coating.

It is well known that Tokina produced some lenses with different focal-lengths for Ricoh (as also for Mamiya) and therefore it is quite possible that those 1.4 / 55mm Rikenon lenses were manufactured by Tokina on the Tomioka Planar design. They may also have furnished the full-metal tubes with knurled grip.

The later Ricoh MC PK lenses are said to have been manufactured by Asahi (Pentax) according to a Mflenses member who is an expert on Rikenon lenses. I cannot comment on that information. In my opinion the Rikenon coating is different from the SMC Pentax coating. The Rikenon lens is more contrasty than the 2.0 / 55mm SMC Takumar (that I owned) with its mild coloring. Ricoh originated as a Japanese governmental research organization and has its headquarters and production facilities within the Tokyo area as have Tokina and Asahi Pentax. Tokina glass was furnished by Hoya.

I have compared the Rikenon 1.7 / 55mm to the EBC Fujinon 1.6 / 50mm for FX bayonet. Both feature about the same length and compact design. The rear element of the EBC Fujinon is wider than the Rikenon and the Fujinon shows a better gradation, better definition in the lights and colors, than the Rikenon that has greater overall contrast.


PostPosted: Sun Oct 20, 2013 11:12 am    Post subject: Reply with quote

***The later Ricoh MC PK lenses are said to have been manufactured by Asahi (Pentax)***

So would my Rikenon XR 28mm f2.8 be made by Pentax Question


PostPosted: Tue Oct 22, 2013 8:48 pm    Post subject: Reply with quote

Excalibur wrote:
***The later Ricoh MC PK lenses are said to have been manufactured by Asahi (Pentax)***
So would my Rikenon XR 28mm f2.8 be made by Pentax Question


I cannot comment on that, but a member of MFlenses who is a Rikenon collector is convinced of it. Asahi Pentax has recently become a part of the Ricoh Imaging Corporation, while Tokina is now owned by the Hoya glass foundry. Remember that Tokina sold a lot of Cosina-constructed and -manufactured lenses under their own brand in the 1990s. It is possible that some of the Rikenon 1.4 / 55mm lenses like those with a convex rear element were made by Tokina according to the Tomioka Planar design. Tokina is known to have manufactured some of the Pentax PK zoom lenses. So we have here a family of production facilities, sharing lens designs and manufacturing glass from different foundries with different levels of perfection.


PostPosted: Thu Oct 24, 2013 12:36 pm    Post subject: Why own a Tomioka lens? Reply with quote

Although the Tomioka Planar design of the 1.4 / 55mm lens was employed by different lens manufacturers besides Tomioka themselves with different coatings to a high standard of perfection, the Tomioka-made lenses stand out because of the purity and luminosity of the glass used and surface finish applied. It is an established fact that Tomioka manufactured some of the Zeiss Contax as well as Yashinon lenses that share peculiar qualities (sharpness, luminosity). Some of the early Zeiss Planar lens tubes and glass surface finishings look very similar to some of the Chinon or Porst multicoated standard lenses.


PostPosted: Thu Oct 24, 2013 12:41 pm    Post subject: Reply with quote

I don't quite understand, are you saying that Tomioka lenses are of a higher standard than other third-party makers? The three or four Tomioka made lenses I have owned were rather less than great, so does that mean Tomioka didn't always make great glass, or does it mean they were actually made by someone else?


PostPosted: Mon Oct 28, 2013 1:51 pm    Post subject: Reply with quote

Quote:
The three or four Tomioka made lenses I have owned were rather less than great


I think that you can only make statements with reference to a particular focal-length lens of a certain lens manufacturer. One can never say that "all" lenses of a certain lens manufacturer are superior in comparison to what?

On the other hand, "all" SMC Pentax lenses share certain imaging qualities that you will look for when chosing an SMC Pentax lens. The same holds true of Tomioka lenses. Lenses with the Tomioka brand were definitely made by Tomioka. Some Chinon, Revuenon, Rikenon and Mamiya lenses can clearly be identified as Tomioka-made.

In optical theory, the quality of a lens is very strictly defined by the relative absence of second-order and third-order optical errors. With aesthetics in mind, there are many other criteria that define the quality of a certain lens, its color characteristics, its signature, etc. Given that, a "cheap" third-party lens may be preferable to a high-priced brand lens. I was quite disappointed by the Nikkor Micro and SMC Pentax macro lenses as compared to the EBC Fujinon macro lens. But if you opt for bristling sharpness in the center of the image, you would probably chose the Tomioka Yashinon lens with its monster tube.