TRI-ELMAR-M 28-35-50 mm

[martinis]

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I was always under the impression that it is a true zoom design and stays in focus throughout although of course you can only be sure of the angle of view at the three set focal lengths.

[thrid]

This rattled something in the back of my mind and I checked Erwin Puts' Leica Lens Manual...

 

Apparently the Tri-Elmar 28/35/50 is a zoom lens after all.

 

The reason why the focal lengths are out of order is necessitated by the need to mechanically select the proper framelines.

With the WATE this obviously is not a problem, since it relies on an external viewfinder for framing, instead of the internal RF unit.

 

 

Quote:

http://www.imx.nl/photo/downloads/files/llcforweb.pdf

 

"From its optical design the Tri-Elmar is a true zoom lens. A zoom lens alters the

focal length of the optical system and thus changes the magnification of the

image when you take pictures from a fixed standpoint. The designer accomplishes

this by employing two groups of lens elements, a back and a front cell. When

both groups are shifted relative to each other and relative to the film plane

the focal length is changed. The front group also moves axially for the

adjustment of the distance setting. The demands on the mechanical engineering

are extremely high. The Leica M employs a mechanical linkage to bring in the

correct frame masks when changing lenses. So the "zoom lens" must have a

mechanical linkage too, in order to activate the correct frames when changing

focal length. And this lens must be designed such that at the three focal

positions the accurate focal length must be set. The designer has to take into

account the demands of all M bodies, including the M3. Every M body has a

coupling arrangement between the lens and the appropriate frame in the

viewfinder. These frames are spring actuated with different tensions and the

sequence is 35, 50, 28. As can be seem from the illustrations, the two cells

move over a bigger distance when going from the 50 to the 28 position than when

going from the 35 position to the 50 position. The relative movement between the

two cells and with respect to the film plane is mechanically compensated by

cams with different curves. The change from 50 to 35 and from 50 to 28 requires

the same distance on the focal-length setting ring, but the internal movements

are quite different, where the shorter distance requires a steeper curve. This

results in different forces to overcome and these forces need to be linked to

the tensions of the frame actuating springs. If we then think about the required

precision as the lens needs to stay accurately focused when changing focal

length, we can appreciate the quality of the precision mechanical engineering

involved in the Tri-Elmar. Every one of the three focal positions is

individually tuned to a very high degree of accuracy when the lens is mounted.

It may be noted that the Tri-Elmar is the lens where the art and tradition of

precision mechanical engineering and mounting is at its current zenith."

 

Also see here:

 

Tri-Elmar

TriElmar 4/28-35-50mm asph

 

WATE

TriElmar 4/16-18-21 asph.

[luigi bertolotti]

"Reasonable" hardy applies to the price one has to pay for a Tri Elmar... ... anyway there is one for sale at Tamarkin - USA, another (1st version) at Schouten - Holland, another at Photo Arsenal - Germany....

[Guest stanjan0]

Andy, I just read your explanation of why the MATE was stopped and it sounds like you have the real info. Thats why I'm sending you this message, I'm looking for the 28-35-50mm f/4 Tri-Elmar and so far all I have come up with is damaged or not so great lens, I thought perhaps you might be of help in this respect and I would give you a finders fee if you got me the right one. Version 2 or 3 are the best types all though I have never seen a version 3 for sale, thanking you in advance. I am 79 years old living in Florida USA. Stanley Janovici

[Guest stanjan0]

Luigi, the one at Tamarkin has a squeaking at f/4 as I was recently in email contact with the owner and he said it couldn't be repaired.

[skueh]

stanjan0,

Too bad you are in Florida. If you are in Southern California, you can borrow mine for a day or two.

[wizard]

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Andy, I just read your explanation of why the MATE was stopped and it sounds like you have the real info. Thats why I'm sending you this message, I'm looking for the 28-35-50mm f/4 Tri-Elmar and so far all I have come up with is damaged or not so great lens, I thought perhaps you might be of help in this respect and I would give you a finders fee if you got me the right one. Version 2 or 3 are the best types all though I have never seen a version 3 for sale, thanking you in advance. I am 79 years old living in Florida USA. Stanley Janovici

 

Stanley,

 

I'd sure like to help, but the only MATE I have access to is my own one, and that's definitely not for sale, as it is one of my most used lenses. Just for your information, there is no version 3 MATE, to the best of my knowledge.

 

Good luck in finding a MATE, preferably a version 2, they do pop up every once in a while.

 

Cheers,

 

Andy