M-42 normals. Different but the same? Again!

casualcollector

December 11, 2012: I dredged this post up from the past as kin to Pancolart's current "Tomioka Myth" thread.

Original post from 2008.
I sat down this afternoon with eight different 50 and 55mm lenses. All eight were M-42 mount, Japanese lenses, of four brands from five camera manufacturers. I had thought that after a bit of examination I'd find some significant variations and have some definite conclusions as to who manufactured which. At first I thought I was going to divide them up between two manufacturers. Mamiya/Sekor’s subsidiary Setagaya Koki (origin of the Sekor half of the name) and Yashica’s Tomioka. I thought there would be noticable differences between the two makers. Now, I’m not so sure!

The lenses. Two Mamiya /Sekor 55mm f-1.8. One black and silver from the TL era, the other all black from the DTL era. 55mm f-1.8 Sears (Rikenon). 55mm f-1.4 Sears (Chinon) from a Sears ES-2000. 50mm f-1.8 Vivitar (Cosina). 50mm f-1.7 Yashinon DX. 50mm f-1.4 Yashinon DX. 50mm f-1.4 Sears (Rikenon).
I had assumed that the Mamiya and Rikenon lenses would all be from Setagaya Koki, The Yashinons, Chinon and Cosina from Tomioka.

Right away, the Mamiya and Rikenon 55/1.8s appeared to be the same lens with differences in the knurling of the focus and aperture rings. All three lenses had an A-M switch at the lower right. The mounting flanges and rear optic groups showed minor differences. Probably just running changes as production evolved over time. The all black Mamiya-Sekor had a more elaborate depth of field scale. The glass looked identical among the three. I was expecting the 50/1.7 Yashinon to be different, and it was. Aperture and focus scales were viewed through openings in a shroud between the focus and aperture rings. On the Mamiya and Rikenon lenses the scales are in full view. Beyond these cosmetic differences I found some similarities among the Mamiya and Yashica units. The lenses are nearly the same in size. Only about a millimeter of difference in any dimension. Relative location of aperture and focus rings is identical. The focus rings look the same except that foot/meter scales are reversed. The A-M switch is in the same, lower right, location. I couldn’t find any significant difference in the mounting flanges. Though the Mamiya and Rikenon lenses are labeled 55mm and the Yashinon as 50mm The glass and coating look much alike. The only difference I can see is that the rear element of the Yashinon extends further back from the mounting face than on the Mamiya and Rikenon lenses. One small oddity, the Mamiya 55s have half stop clicked aperture rings, the Rikenon 55 and Yashinon 50 are clicked at full stops! For as much as I was thinking these lenses came from two different makers, they sure look like they came out of the same factory.

The Vivitar (Cosina) 50mm f-1.8 is a slightly smaller lens. About three millimeters shorter and with a 49mm filter ring vs the 52mm of the others. The focus ring is a bit narrower with a rubber grip, the aperture ring a bit wider than the others. On this lens you view the depth of field scale through a cutout area of the aperture ring. The location of focus and aperture rings, location of A-M switch, mounting flange details, distance scales are all very nearly the same as the other group of lenses. The glass looks the same as the Yashinon optics, though the front element appears smaller in diameter. Oh, half stop clicks on the aperture ring. Overall, this lens looks like a member of the same family as the above four.

I really started this little examination not fully believing that Tomioka, who seems to get all the credit for these lenses, really produced them all. It seems odd that one manufacturer would supply lenses of 50 and 55mm focal length with f-1.7 and f-1.8 maximum apertures. I think it makes more economic sense to make them all to one specification. The differences among these lenses could be accounted for as changes in manufacturing techniques over approximately seven to ten years from oldest to newest. Or maybe they were made in different plants from the same plans. The f-1.4 lenses get a bit more interesting but this post is more than long enough for now.

What do you think?

Bill

luisalegria · Expire: 2018-01-18

Very interesting comparison.

I'm inclined to think that they are all in fact from Tomioka. The Yashica is the interesting one, but its clear that Yashica was going for a distinctive and unified look for this series, so they probably paid more for substantially different cosmetics.

The minor differences in specification are not unbelievable, as these things may not be entirely accurate, and can be "tweaked" a bit. I recall articles where the "true" focal length was measured and it was never exactly on. I can believe that the same can happen with aperture. Perhaps the thing is really f/1.75, and one vendor calls it 1.8 and the other goes for 1.7 ?

You have prompted me to pull out my 1.) Auto Mamiya-Sekor 55/1.8, 2) Auto Sears 55/1.8 (came with a Sears/Ricoh TLS, so the same as Ricoh Rikenon) and 3. Auto Sears-Sekor SX 55/1.8 (clearly came with Sears-branded Mamiya SX). These are obviously exactly the same lens, with cosmetic, production and feature differences - like the SX lacking an m/f switch, but even so.

The optics look the same, front and rear element diameters are identical, dimensions are the same, locations and spacing of rings, etc. likewise, even the coating looks to be the same golden color.

estudleon · Joined: 15 May 2008 Posts: 3754 Location: Argentina

Interesant question!! Can you send the lenses images? It can help to whom doesn't have them.

Rino.

casualcollector · Posted: Sun Sep 07, 2008 6:48 pm Post subject:

For you, Rino.

All from the front.

All from the back.

Mamiya/Sekor 55/1.8 black and silver.

Mamiya/Sekor 55/1.8 black.

Sears(Rikenon) 55/1.8.

Vivitar(Cosina) 50/1.8.

Yashinon 50/1.7.

Bill

rick_oleson · Posted: Sun Sep 07, 2008 6:56 pm Post subject:

Have you disassembled the lenses? If they are essentially the same lens with different badges, the internal mechanical details should be nearly identical... if they are from different manufacturers you will surely find a lot of detail differences in internal construction.

patrickh · Expire: 2011-11-18

Bill

Thanks for the hard work and those pictures are going to help a lot of us

patrickh

casualcollector · Posted: Sun Sep 07, 2008 7:17 pm Post subject:

Hi Rick! Good to see you here

The name and filter ring have come off one of the Mamiya and Sears badged lenses fairly easily. They look the same. The Vivitar and Yashinon have not been as cooperative as yet. The front end came off the 50/1.4 Yashinon quite easily and it is a ringer for what's in the front end of the Mamiya and Riken lenses. All have 6 bladed irises with the tips of the blades visible through the front. The Vivitar and Yashinon have a subtle curve to the blade tips that the Mamiya and Riken lenses don't. They appear to be later lenses and that could be an evolutionary change.

Two other M42 lenses have the blade tips visible through the rear. One is a 55/1.4 Sears from a Chinon supplied camera. This is generally considered a Tomioka lens but differs in several respects from the 50/1.4 Yashinon. The other is a 55/1.8 Petri. Obviously not from the Mamiya or Yashica camps.

I have to get some money off to you someday soon for your tech notes CDs. Need to learn better how to get these things back together!

Bill

peterqd · Expire: 2014-01-04

Thanks for this interesting topic Bill, and your long message! Smile

I don't have any of these lenses myself but I'd like to chip in if I may.

The barrel of the Sears lens resembles a Takumar. Were these lenses sold with Spotmatics in USA? If so, they may have been made by Asahi and rebranded - just a thought.

And does the Vivitar have a serial number? Usually the first two numbers of the serial indicate the manufacturer, have a look at this site:
http://www.cameraquest.com/VivLensManuf.htm
(Apologies if that's how you got the Cosina reference)

orly_andico · Joined: 02 Jul 2008 Posts: 253 Location: Philippines

while the barrel of the Sears resembles a Takumar, the Takumar's had the focusing scale in a little "window" (kinda like the Yashinon) -- this is true up to the K-mount SMC 50/2 "M" but the 50/2 "A" doesn't have the little window anymore.

peterqd · Expire: 2014-01-04

LucisPictor · Expire: 2013-12-03

koji · Expire: 2012-12-27

Hi Guys,,

I do not believe all those lenses were made by Tomioka factory,
they could not possibly made them all, IMHO.

But think those companies collaborated each other, quite well known fact
is the Chinon lenses were made by Tomioka, but often made by Cosina.

If you know that these companies are located very close each other
in NAGANO prefecture in Japan. They are literally within shouting distance
except Cosina where it resides in the same prefecture but a little off.

Mr.K once told our group (called Normal_lens_party) that
PORST 55/1.2 was Tomioka designed, but from the beginning Cosina
made them all, but later stage Cosina started producing PORST 55/1.2
by their optical design (YES, Cosina designed, not typo). That is why
PORST 55/1.2 has wildly different reviews depending on WHICH one.

So when you pick PORST 55/1.2, check the serial numbers starting 00
which were Tomioka designed, but later ones serial started 9 I think.
The serial 00xxxx model has less than 50cm MFD, aperture blades 8.

And also RIKENON P&XR 55/1.2 and Cosina 55/1.2 all these have
different optics than PORST 55/1.2 early type.

What I wanted say is not who made what, but those companies helped
each other to make lenses and also try to survive after the WWII.

End of short story.
Have a nice day.

koji · Expire: 2012-12-27

Addenda:

Why is it like that those companies in the same prefecture?
Nagano prefecture is in mountainous country and has cleaner air
to make precision mechanics, that is the main reason. And
this prefecture has the highest education level in Japan, since
feudal age the lords encouraged the population to spend
money for the education, this prefecture cannot produce rice
well (due to high elevation), they had to produce cash crop
such as silk, cloth, and paper (washi=japanese paper).

Cosina: Nakano-shi (northern part of Nagano)
Chinon: Chino-shi
Seiko: Suwa-shi
Tomioka: Shimo_Suwa-shi

The last three area (city) are located in central Nagano prefecture.

Seiko (watch maker) was originally called SUWA-SEIKO-SHA,
which is one of biggest privately owned companies. The Hattori
family has a famous building in Ginza Tokyo with a clock tower
on the top. Seiko still produces shutter for cameras but more
famous for EPSON printers. Oh yes they makes watches too. Very Happy

Farside · Expire: 2013-12-27

Thanks, Koji. Much appreciated; I like to know a bit about the background of makers.

luisalegria · Expire: 2018-01-18

Very interesting information Koji.

What do you know about Tokina ?

Did they subcontract production/license designs to or from others ? Because it seems to me they must have made huge numbers of lenses very quickly.

koji · Expire: 2012-12-27

Hi Luis,

According to my friend, who is THE Yashica collector in Japan, the most of
tele-photo lenses are made by Tokina for Yashica ML-line tele-photo,
possibly for DSB's. I do not know about ML-zoom lenses, except ML
28-50/4 zoom were made by Yashica (ie, Tomioka in this case).

I do not know other things much, even the story I wrote in here is
from the books and my friend who are knowledgeable about Rikenon
55/1.2 et al.

The photo was at RICOH camera factory when I was grade 5 or 6,
1955~1956 the most of those optical companies were operating
in this kind of wood building in the back ground. Shocked

We went a school trip to the factory inside Tokyo, I think.

The economy was getting better those days, mainly due to Korean
war. (Can you find me in this photo?)

estudleon · Joined: 15 May 2008 Posts: 3754 Location: Argentina

http://www.tlr-cameras.com/Japanese/Tomioka%20Lenses.html

http://www.tomioka.de

I only know this.

Rino.

casualcollector · Posted: Tue Sep 09, 2008 11:24 pm Post subject:

Koji,

I find your posts interesting and reinforcing some of my assumptions. Having learned that Yashica, Chinon and Cosina were all in Nagano prefecture, I assumed there was some cooperation among the three.

On a much older version of the Chinon web site, the history stated that the company went onto business making lens components. It leads to the thought that Tomioka may have been the facility that shaped the glass elements and Chinon made mounting and barrel components. Assembly could have taken place at either location or at another. Perhaps Mamiya placed orders for glass components with Tomioka, then had Chinon manufacture barrels with Mamiya specified styling and finish for assembly in Tokyo, all based on a Tomioka prototype.

I am told that Japanese manufacturing was less integrated than American or European in the 50s and 60s. Small shops, often one person or family shops would produce one component for many manufacturers.

Just before I moved away from Vermont I spent two weeks working in a friend's machine shop. He specialized in producing gears and remanufacturing gear cutting equipment. The project I worked on was cutting the sprocket teeth on the clutch housing/primary drive gear for a popular American motorcycle. It was not a project for the motorcycle manufacturer but for an aftermarket supplier. As such, we were a sub-contractor to a sub-contractor who was supplying a specific component to the designer/seller for use in the final product!

Bill

luisalegria · Expire: 2018-01-18

Hi Koji,

Nice picture !

You were the guy in the sweater and baseball cap ?

koji · Expire: 2012-12-27

No sir. hehe

Katastrofo · Expire: 2013-11-19

Koji, you're the boy in the white shirt, front row, in the middle, looking
right at the camera?

I've enjoyed this thread immensely, thanks for sharing your knowledge. It
seems these different companies formed their own perhaps informal,
horizontal keiretsu, in order to survive, very interesting!

My tours in Japan:

MCAS Iwakuni 1988-1993
Sasebo 1997-1999

You could have all four car windows rolled down, a roll of yen notes on the
front seat, key in the ignition, leave it for two weeks, and all would still
be there upon your return.

koji · Expire: 2012-12-27

No sir again.

Katastrofo, you must have visited as a military duty.
Or a military person, weren't you?

ChrisLilley · Joined: 01 Jan 2008 Posts: 1767 Location: Nice, France

Koji,

Many thanks for the informative posts, very interesting reading.

By Mr K. I assume you mean Kobayashi-san?

koji · Expire: 2012-12-27

Yes, sir. Mr. K is Mr. Kobayashi.

Katastrofo · Expire: 2013-11-19