manufacturer downstopped lens

AgX · Nov 29, 2015

I found a peculiarity at lenses whilst comparing cameras out of the Agfa Optima Sensor range.

-) Agnatar 40mm 3.5

-) Solitar 40mm 2.8

Both lenses are listed as Tessar types.
Both show exactly the same reflections, in size, position and colour.

However, both front lenses have the same diameter. (I know, front lens diameter is no true indicator for relative aperture, but with a Tessar-type this should be the case.)

Then, at further inspection I realized that the slower lens has a smaller fixed aperture (aside of the diaphragm aperture).

Thus seemingly both lenses are identical except for that installed smaller aperture ring.

Either to yield a bit more DOF (not likely) or to offer a cheaper model (that actually is in production costs identical to the more expensive one).

Do you know other cases where a camera is deliberatedly downgraded (without reducing costs) just for marketing reasons

Fixcinater · Nov 29, 2015

Pentax Super Takumar 55mm f/1.8 vs. 55mm f/2.0 is one that springs to mind.

Nodda Duma · Nov 29, 2015

I bet the slower lenses were assembled from elements that didn't meet the fabrication tolerance requirements for the faster lens assemblies.

summicron1 · Nov 29, 2015

the smaller opening may be to eliminate optical problems that ensue when the lens is wide open.

I've got several lenses where they have very obviously put a much smaller fixed opening in the lens than it was built for -- my Voigtlander 15 comes to mind.

An excellent example is my Canon LTM 25mm lens, a very old lens that, when stopped down a couple stops, is sharp as a tack but wide open (which is about f 4.5, i think) it gets a really interesting glow that is even visible on the negatives, and it is obvious from looking into the lens that even this "widest" stop is less than it was made with originally.

So yes, both lenses may be the same, but open that larger one wide open, it may go wonky on you. Even Leica lenses of high repute only get really really good at f 5.6 or 8.

jcofer · Nov 29, 2015

Supposedly the 50mm f2.0 lens on the Kodak Retina IIIc and the 50mm f2.8 lens on the Retina IIc are the same lens with a restriction on the diaphragm opening mechanism on the IIc.

Xmas · Nov 29, 2015

summicron1 said:
the smaller opening may be to eliminate optical problems that ensue when the lens is wide open.

I've got several lenses where they have very obviously put a much smaller fixed opening in the lens than it was built for -- my Voigtlander 15 comes to mind.

An excellent example is my Canon LTM 25mm lens, a very old lens that, when stopped down a couple stops, is sharp as a tack but wide open (which is about f 4.5, i think) it gets a really interesting glow that is even visible on the negatives, and it is obvious from looking into the lens that even this "widest" stop is less than it was made with originally.

So yes, both lenses may be the same, but open that larger one wide open, it may go wonky on you. Even Leica lenses of high repute only get really really good at f 5.6 or 8.

Some ultra wides are so limited physically it is easier to fit a wider range iris and use a limited range the 28 mm FSU f/6 a similar example. They are ok at f/6.

blockend · Nov 30, 2015

Not a lens, but I believe Pentax Spotmatics with 1/500 maximum shutter speed had the same top speed as the 1/1000 but it wasn't marked on the dial. Nevertheless there was an extra notch that offered the same speed as the more expensive model.

AgX · Nov 30, 2015

Thank you all. That all is very interesting.

In the case of those Agfa lenses I assume it was indeed a marketing thing.

Nodda Duma,
Does the manufacture of Tessar-type lenses could produce so much off-limits samples that it could reason a separate line of cameras (with stopped down lenses)? I find this utmost hard to believe.

georg16nik · Nov 30, 2015

AgX said:
I found a peculiarity at lenses whilst comparing cameras out of the Agfa Optima Sensor range.

-) Agnatar 40mm 3.5

-) Solitar 40mm 2.8

Both lenses are listed as Tessar types.
Both show exactly the same reflections, in size, position and colour.

However, both front lenses have the same diameter. (I know, front lens diameter is no true indicator for relative aperture, but with a Tessar-type this should be the case.)...[].

Given that these are most likely made by 3rd parties somewhere in Asia, then shouldn't be surprising in case they are the same optics - the slower lens simply didn't pass the requirement for the “faster” one.
Could be a small set screw that limits the slit travel @ wide open to ease mfg process.

AgX · Nov 30, 2015

I'm quite sure the cameras were completely manufactured in München.
The only asia-made Agfa cameras in that period were some Super-8 cameras made in Japan by Minolta and SLRs made by Cosina.

Their München camera-plant had at least 3000 employees.

Nodda Duma · Nov 30, 2015

AgX said:
Nodda Duma,
Does the manufacture of Tessar-type lenses could produce so much off-limits samples that it could reason a separate line of cameras (with stopped down lenses)? I find this utmost hard to believe.

When you do a production run, you either tolerance the optical fab and assembly for 100% yield or you loosen up the tolerances and make them cheaper at a lower yield. So then you either scrap the rejects or find a way to use them.

Conversely, you tolerance for 100% yield and some of the assemblies come in so good that you can open up the stop and sell them at a premium. But I think the former is the case (looser tolerances for cheaper at lower yield, stop down the rejects and sell instead of scrap).

Gerald C Koch · Nov 30, 2015

I have never seen this design for camera lenses but it is fairly common with enlarging lenses. I have a couple of Schneiders that have this design. The idea is to limit distortion caused by peripheral rays passing through the lens.

georg16nik · Nov 30, 2015

AgX said:
I'm quite sure the cameras were completely manufactured in München.
The only asia-made Agfa cameras in that period were some Super-8 cameras made in Japan by Minolta.

Their München camera-plant had at least 3000 employees.

Manufactured? Some QA and screws tightening may toke place in München.
Everything else - Coimbra, Portugal and Asia - Chinon, Cosina etc.
There are entire product ranges marked as Agfa made by the above entities as well.

AgX · Nov 30, 2015

3000 people tightening screws...?

georg16nik · Nov 30, 2015

AgX said:
3000 people tightening screws...?

How do you explain the fact that most of these 35mm snap cameras available in cosmetically different shells and diff nameplates share pretty much the same parts.
The Agfa plant München made parts for Chinon, Cosina and other OEM's... or the other way around?

AgX · Nov 30, 2015

None of the Optima range ever came in different shells or brands.
The first model even was the worlds first program-automated camera!

The only cameras Agfa bought in in that period were those from Minolta and Cosina mentioned above.

There is no sense it ridiculing german manufacture. When that plant was closed in 1982, after many, many years in red, it was a spectacular closing in West-Germany due to its size.

John Koehrer · Nov 30, 2015

AgX said:
3000 people tightening screws...?

Screwing around?

georg16nik · Dec 1, 2015

AgX said:
None of the Optima range ever came in different shells or brands.
The first model even was the worlds first program-automated camera!

The only cameras Agfa bought in in that period were those from Minolta and Cosina mentioned above.

There is no sense it ridiculing german manufacture. When that plant was closed in 1982, after many, many years in red, it was a spectacular closing in West-Germany due to its size.

There is no ridiculing of german or other manufacturers.
Take a look at the photos.

AgX · Dec 1, 2015

You are ridiculing again.

The Agfa Optima sensor is a camera of great design. Very similar to a camera praised here at Apug, Makina. (Who copied whom?)
Furthermore it has the best viewer of all finder cameras. A Albada viewer that beats any brightline viewer.

What you did is looking for the rare version with built-in flash that indeed is design desaster.

Concerning manufacture:

As you see the models are not identical.
Furthermore it was not uncommon for a german manufacturer after a model was outdated to sell the tools etc. to an asian manufacturer for production for the overseas market.
There also was copying of german design.

Concerning this very model,
there is a site (the only source I found for one of the photos you presented) that just confirms my general statement on follow-up production for this model.
Dead Link Removed

georg16nik · Dec 1, 2015

There was copying of German design - no doubt about it.
Dead Link Removed talks about the Agfa factory that produced the last Optima sensor cameras but that's not the Agfa factory in München that closed in 1982 but the Agfa factory in Portugal, sold in 1984 to Reflecta, who the made slide projectors and other stuff there.

AgX · Dec 1, 2015

The closure started end of 1982 and run up to the end of 1984. I do not know which products were made in the remaining two years. It could well be part of the Optima Sensor range.

My own collection shows Agfa samples whose origin seemingly is different from what is generally stated on the net. And it may be that part of the camera production was transferrerd abroad even one medium-class chassis generation earlier (cameras of same chassis made completely made in München others assembled abroad).

But I still do not understand why by all means you want to draw a line to a production abroad. As if manufacture quality abroad necessarily would be worse. Even Leica have their cameras basically manufactured in Portugal.

flavio81 · Dec 1, 2015

AgX said:
But I still do not understand why by all means you want to draw a line to a production abroad. As if manufacture quality abroad necessarily would be worse. Even Leica have their cameras basically manufactured in Portugal.

And i owned a Voigtlander VF35 made in singapore which had really, really good build quality.

manufacturer downstopped lens

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