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12-22-2015, 06:00 PM   #1
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Seen on ebay: a lens raises questions about design intentions.

"Lens, Cosina 55mm f2.8 M42 Mount"

In an era where lenses of this focal length were commonly up to two stops faster, when film speeds were low and every stop was precious... WHY? What exactly did they get in exchange for this compromise?

Of course the same thing applies even more to the Industar 50/3.5. The gain there is its remarkable compactness, but it comes at the expense of both speed and handling (it's a very fiddly lens to use, as those who have it know only too well).

The Takumar 50/4.0 macro is similar, but that was optimised as a flat field copy lens to be used from a stand, where the camera is rigidly held, remotely triggered, lighting can be optimised, and considerations of camera shake and shutter speed are irrelevant.

12-22-2015, 06:23 PM   #2
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QuoteOriginally posted by pathdoc Quote
What exactly did they get in exchange for this compromise?
I dunno...cheap price? When I bought my Ricoh Singlex TLS back in 1970 there were three kit options, 55/2.8, 50/1.7, and 55/1.4. The 55/2.8 was no additional cost while there was extra expense for either of the other two. I suspect that Cosina followed a similar market strategy.

BTW...while fast 50s (f/2.0 and wider) have been pretty much the norm for the last 50 years, the other three focal lengths common in a "three lens kit" (28mm, 35mm, 135mm) were typically f/2.8 or f/3.5 and nobody thought much about it. I have no qualms shooting ISO 100 film with my S-M-C Takumar 28/3.5 or Vivitar 135/2.8 or Vivitar 200/3.5.




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12-22-2015, 06:42 PM   #3
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QuoteOriginally posted by stevebrot Quote
BTW...while fast 50s (f/2.0 and wider) have been pretty much the norm for the last 50 years, the other three focal lengths common in a "three lens kit" (28mm, 35mm, 135mm) were typically f/2.8 or f/3.5 and nobody thought much about it.
True, and that's why I restricted terms of reference to the 50-55-58mm type lenses. Your cost example is a good one, but even so, two extra stops seems a lot to lose when even the slowest Pentax kit fifty is f2.0.
12-22-2015, 07:25 PM   #4
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QuoteOriginally posted by pathdoc Quote
True, and that's why I restricted terms of reference to the 50-55-58mm type lenses. Your cost example is a good one, but even so, two extra stops seems a lot to lose when even the slowest Pentax kit fifty is f2.0.
Most people bought f/1.8 or f/2.0 kits. That is a 1.3 and 1 stop difference from f/2.8 respectively. The price to upgrade was minimal (typically less than $20) and the faster lenses options were generally superior in all regards. As a result, the Cosinon 55/2.8 you reference is sort of rare. I have been involved with photography since the late 1960s and can't remember ever seeing a Japanese SLR in the flesh with a f/2.8 kit lens. They were definitely available (duh, most makers offered them), but I have never seen one.


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12-22-2015, 07:30 PM   #5
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The design intention is to keep the cost down. The slower the lens the less glass you have to put on it - smaller lens, less elements. To someone stepping up from a fixed lens budget rangefinder camera with a typical 50mm f/3.5 lens they would feel right at home with one of theses lenses. For someone stepping up from a point-and-shoot with fixed focus, aperture and shutter speed one of these lenses would be an unbelievable upgrade. If you're shooting on sunny days where the "Sunny 16" rule applies you seldom need anything wider the f/3.5. People buying these lenses were probably taking "snapshots" under these conditions a good percentage of the time.
12-22-2015, 09:17 PM   #6
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By way of another example, Ricoh had a f2.2 in their line up at one stage.
12-23-2015, 01:31 AM   #7
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etc.

QuoteOriginally posted by southlander Quote
By way of another example, Ricoh had a f2.2 in their line up at one stage.

And Vivitar also sold a 55mm f2.8 kit lens.


QuoteOriginally posted by Not a Number Quote
The design intention is to keep the cost down. The slower the lens the less glass you have to put on it - smaller lens, less elements. . .
QuoteOriginally posted by stevebrot Quote
I dunno...cheap price? When I bought my Ricoh Singlex TLS back in 1970 there were three kit options, 55/2.8, 50/1.7, and 55/1.4. The 55/2.8 was no additional cost while there was extra expense for either of the other two. I suspect that Cosina followed a similar market strategy. . .


Years ago, Sears sold rebadged Ricoh cameras and lenses. Here are some figures from their 1970 Fall / Winter catalog:


TLS camera with 55mm f/1.4 lens (7 element) $179.50
TLS camera with 55mm f/1.8 lens (6 element) $149.50
TLS camera with 55mm f/2.8 lens (4 element) $119.50
12-23-2015, 03:25 AM   #8
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A couple of weeks ago, there was an eBay offer of a "Pentax 2.8/50mm", in K-mount.

I wondered where this came from, but the pictures showed the offer was real
The lens looked as K or M series, with a slightly smaller front lens than the 2/50, and the colour of the coatings did not look as SMC.
The front ring did not say "110" or "Macro". It went for not much money.

It is neither in our lens data base nor mentioned by Bojidar, and also Google does not show anything. Perhaps a prototype?

12-23-2015, 04:42 AM   #9
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That would almost have been worth snapping up just to have it and examine it. Unless of course the price was astronomical.
12-23-2015, 07:11 AM   #10
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QuoteOriginally posted by RKKS08 Quote
A couple of weeks ago, there was an eBay offer of a "Pentax 2.8/50mm", in K-mount.
You can search recent closed listings on Ebay. It could be this auction. Advertised as a 50/2.8, but actually a 50/2. Didn't sell, AFAICT.
12-23-2015, 08:50 AM   #11
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Industar

I believe the Industar was first designed as a tessar type four element COLLAPSIBLE lens intended for the Russian made Leica like cameras. It was supposed to look like a Leica Elmar. This was an LTM lens. Therefore it had to be very narrow. The glass, mount, slide mechanism, and lens body all had to fit into a 39mm wide opening. The lens was later adapted to a rigid form for Zenit SLRs retaining its heritage.

Industar-22 - Camera-wiki.org - The free camera encyclopedia
12-23-2015, 09:19 AM   #12
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QuoteOriginally posted by lmd91343 Quote
The lens was later adapted to a rigid form for Zenit SLRs retaining its heritage.
As this link from the original article you quoted tends to support. Thanks for that.

BTW, what's an LTM lens?
12-23-2015, 10:08 AM   #13
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QuoteOriginally posted by pathdoc Quote
As this link from the original article you quoted tends to support. Thanks for that.

BTW, what's an LTM lens?
Leica Thread Mount

It is thirty nine millimeters in diameter.

I have I-10, I-22, and I-50 lenses.
12-23-2015, 11:02 AM   #14
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QuoteOriginally posted by lmd91343 Quote
Leica Thread Mount
OK, thanks. I've seen M39 a lot but hardly ever LTM. (I was thinking "Leica-type mirrorless", to be honest, but I wanted to be sure.)
12-23-2015, 11:25 AM   #15
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QuoteOriginally posted by pathdoc Quote
OK, thanks. I've seen M39 a lot but hardly ever LTM. (I was thinking "Leica-type mirrorless", to be honest, but I wanted to be sure.)
LTM differentiates it from FED (39mm x 1mm), Zenit M39 (45.2mm focal flange for SLRs) and Canon J-mount (24 TPI threads).

LTM is 39mm x .977mm with 26 TPI threads and focal flange of 28.8mm.
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