135 Elmarit, a hacksaw, and a 1.25 magnifier

Need I say more.

 

Does anyone know if lens would give correct RF operation with the

eyes removed?

 

I suppose the - linearity - of the lens would remain the same, so I

coiuld always add/subtract some length from the RF tab on the back of

the lens.

Charles,

While, I can see the "logic" of what you are trying to do. I think it would be a GREAT mistake to remove the eyes from a 135mm Elmarit and use just the 1.25 magnifer. Why not use BOTH? I have and it makes focusing easy.

Well, the eyes are a nusance to look through for one. Another problem is Sherry and Dag wont align or clean them, saying its such a PITA to get them re-aligned for both field of view correctness and RF correctness that it takes about 6 hours, trial and error (Sherry's quote). Sherry said even Solms charges up the wazoo to clean/adjust those eyes.

 

Sadly, many fine lenses are out there, but the eyes are either fogged, broken, out of alignment, or otherwise unsuitable. And.. if the eyes were perfect, you then still have the image problem in the viewfinder (sort of tunnel vision effect).

I think the answer is that no, the linearity will not be preserved, so don't try it.

I'm having a hard time following that... why wont the linearity be preserved? I mean the eyes are just magnifiers, no zoom there as you focus.

 

By linearity, I mean tracking of focus from infinity to close. I think it might be "off" as far as overal focus goes, but should track the same.

 

I'd really want to know why its otherwise, if anyone has an explaination.

Charles,<P>Try the Visoflex way instead. I'm trying it myself these days. Adds minimally to a 135/2.8 Elmarit's bulk but promises an SLR style viewfinder/rangefinder with DOF control. Only way to use anything beyond 75, IMHO.

Linearity is not preserved in the same way that the linearity of the 35mm goggled lenses is not. (Which posts you should track down and read). The lens moves correctly to the scale printed on it, but the cam on the back is adjusted to compensate for the magnification of the eyes. With no eyes, there's no linearity. After you saw off your eyes and mess up the lens, however, I'll buy it from you, cheap. :-)

There's no cam, but a tab, that is affixed to the focusing helical which is recessed into the body of the lens.

 

I can see I'm going to have to measure the tab on a lens, and compare it to the tab on a non-eyed lens to see whats going on there. Its still my guess that I can lengthen or shorten the tab, to adjust its overall focus, and have it track effectively, as there really is little difference between using the magnifier on the eyes, or the one on the eyepiece.

 

Sounds like I have homework to do, unless someone can explain the why's of this to me

No, there's a cam--it's on the other end of the tab, buried up inside where you can't see it. Notice how when you focus the lens moves in and out a lot, but the tab only a little bit--that's the effect of the cam. There's always a cam of some sort--it may be disguised as a helical with a different movement (as on the w/a lenses) but it's there--the only lens which can focus with a 1:1 movement of lens to RF roller is the 50mm. Don't be stubborn, now! :-)

Here--read this thread:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=002ecB

 

and try to explain why the same thing doesn't apply to the 135.

A number of people have mentioned the mis-alignment of the "eyes" with the 135mm Elmarit-M. Remember this is with the EARLY versions. The lens was redesigned and the "eyes" and the mount are one piece. I've had one of these newer lenses for years and have NEVER knocked it out of alignment.

Mike, the difference is this - the 35mm has a circular ring, directly connected to the focusing helical of the lens. There are two helicals, one that moves the lens, the other that moves at a different rate to actuate the focus. On the 35mm lens, the length of that ring is off. On the 135mm lens you've got the arm with the tab, similarly connected to a focusing helical, but much easier to adjust since it doesn't move in a circle as you focus.

 

Here's the concept - all Leica lenses must convert the amount of movement the lens requires to be in focus into the amount of movement a 50mm lens requires to focus, since that is the amount of movement the RF arm is calibrated for. Its a simple ratio in the thread pitch of the two helicals in the lens. While the eyes can alter the overall focusing equation, for example 50mm/135mm+2mm, the equation remains linear and the offset, I really believe, can be compensated for easily in the case of the 135mm lens. I say easily, because its a simple tab, not a rotating ring, and on a simple tab, its length can be mechanically adjusted in and out without too much hoopla.

Well, try it. I'll give you $100 for the glass after you're through, if it's in good shape. :-)

I'm getting a 2nd opinion on this from another source, but... it looks like a go. Mike I'll let you know how the operation goes.

Charlie,

I agree with Lutz. Find a short focusing mount for the 135 F2.8(the same mount will work for any of the older 90MM Summicrons) and use the visoflex. Slightly bulky but the results can be outstanding.