Quality issues Tessar on Rolleiflex MX-EVS model K4B ?

[jim_rais]

<p align="justify">

I remember reading vaguely somewhere that there are some quality issues regarding Tessar Oberkochen used in the

early MX-EVS model K4B / type 1, but cannot find the article. Can someone explain what kind of quality issues are

those? Ferdi, maybe? Thanks.</p>

[steve salmons]

Are you perhaps thinking of the mismatched Tessars released with some 2.8A Rolleiflexes in 1949? These cameras were subsequently recalled for replacement lenses

[kerkko_kehravuo]

No "issues" at all. A Zeiss Tessar is A Great Performer, always. I love my MX-EVS and when observing it's chromes at light table with a loupe of 15x magnification difference to 2,8F or 2,8GX is rather limited. Maybe I have a good example?

 

Kerkko K.

[photo5]

I had an MX-EVS Type 2 (with the EV system you could uncouple) and the Tessar was very sharp. Steve is right, there were performance issues with the 2.8A Tessar, which is why they switched to the Planar and Xenotar in subsequent models. The Zeiss-Opton Tessar in my Rolleiflex Automat X is just as good as in the MX-EVS, which it should be as it's the same lens just from a different factory.

[photo5]

OK, are you referring to this?

 

http://www.rangefinderforum.com/forums/showthread.php?p=703488

 

Here is the text in case the hosting site ever goes down. It's good information. I've owned one Rolleiflex with the Opton-Tessar and it was sharp as a tack. I've just recently bought another and have yet to process film from it, so I am not sure. The sharpness can be checked with a focusing screen at the film plane, however, before purchase if possible. Here is the post:

 

Originally Posted by Seele

I have a Rolleiflex MX with Zeiss Opton Tessar too and it's been serious headache. Consultation with other collectors and users, after examining the disassembled lens, revealed something very interesting.

 

The short answer: the Zeiss Opton Tessars are fine regarding the glass bits, but the way they were mounted was unbelievably idiotic and prone to failure.

 

The long answer: the Tessar is a four-element lens in three air-spaced groups, with two air-spaced elements at the front and the cemented group at the back. When mounted in a leaf shutter, the front and back cell units are screwed into the shutter body.

 

Looking at the front first: there are many ways to fit two air-spaced elements together and then to the shutter; one main consideration is to keep the distance between the elements constant and the optical axes aligned. In the Zeiss Opton Tessar, the front cell was made to fail: the front-most element is dropped into the cell, resting on a ridge, and then a retainer ring screwed in from the front; no problem here. But the inner cell was dropped into the cell through the back, and then glued into position. When the glue fails, the correct positioning is lost, and you get a big blur on the negative.

 

At the back, the usual arrangement is to drop the cemented doublet into the cell and the cell is spun, as in using a tool to bend the edge of the brass cell so as to grab the doublet in position. An alternative method is to screw in a retainer ring to hold it in position. Here, the doublet was dropped into the cell and then held by glue. That is also a recipe for disaster; on my example the doublet slipped out of position by more than a millimetre; coupled with the issue at the front I did not even get a blur on my negative.

 

Fortunately a local optical specialist had it put right for me... at a price of course.

 

By the way it seems, a significant proportion of Zeiss Opton lenses suffered from this sloppiness and absence of commonsense. At the same time the people at the original Jena works still did things the proper way. For my money, if there are two identical cameras with Tessars, one by Carl Zeiss Jena, and the other Zeiss Opton, you know which one I would pick.