Voigtländer Bessa "E-messer" - how do I adjust the rangefinder?

[abeku]

Hi!

I recently picked up a prewar Bessa with a Scopar lens, also known as the "E-messer". The lens is a great performer but after a few rolls I can conclude that the rangefinder needs a minor adjustment to focus right.
Does anyone of you having any experience of doing this with a E-messer? I even cannot really figure out how to remove the top lid!
Hints and suggestions are welcome, thanks!

 

[Rol_Lei Nut]

Are you sure it's the rangefinder and not the focus collimation?
When the focus is set to infinity, is the image sharp at full aperture? Does the rangefinder not agree with infinity?

My E-M Bessa is missing the cover over the distance scale (with the DOF scales): Clearly visible are two screws holding an adjustment cam - though I suspect that is for the focus collimation.

Most such cameras require removing the leatherette to access the screws holding the top on. You could try removing the small leatherette patches on the front & back first - if you're lucky that will uncover an access hole to a RF adjustment screw (or one could be under the top leatherette).

If no-one has no more precise information, I hope this helps.

 

[abeku]

Thanks for prompt reply. To be honest, I haven't thought of the focus collimation. I need to do some test additional tests to sort it out.
So the distance scale is removable? Can it be pulled out by using a fine screwdriver or does it need to be removed in an other way?

 

[elekm]

As I understand, you have to remove the leather covering to access the screws to adjust the rangefinder. The Skopar lens (a Tessar design) should be very sharp.

 

[Samuel Hotton]

Abeku, you do not have to take anything off except the leatherette on the very top of the camera. The screws are on the top left side. IF the rangefinder is working correctly, but the focus is still out, then you perhaps will have to shim the lens.
Sam H.

 

[Rol_Lei Nut]

So the distance scale is removable? Can it be pulled out by using a fine screwdriver or does it need to be removed in an other way?

On mine it looks like it was glued on (it was already missing when I got it), so gentle prying is probably needed..

Despite another post, those two screws I mentioned are *very probably* for collimating the focus and should be LOTS easier than playing around with lens shims.

 

[Rol_Lei Nut]

So the distance scale is removable? Can it be pulled out by using a fine screwdriver or does it need to be removed in an other way?

Please note, I was talking about the inside scale - the depth of field scale, NOT the distance scale itself.

Pedantically repeated: The inside part of the focussing ring, which is exactly the size of a 50 Euro Cent coin (hey, maybe that's what I'll use to cover it!) is the glued on removable part.

 

[abeku]

Thanks gentlemen, your comments have been most helpful! I'll post later about the progress I'll make. It's nice to know to that there are some other Bessa users out there!

 

[abeku]

So... I have removed the DOF scale and the distance scale and loosened the screws in order to set the focus at infinity (by using a ground glass and a loupe). After that I checked the camera, mounted on a tripod, by aiming at various objects in my garden. I noticed that the most severe error occurs on the a distance of 3m/9ft, where the focus on the ground glass is about 05m/2ft behind where I set the focus by using the rangefinder. Perhaps I'm too picky and this is the accuracy one should expect from such an old rangefinder? How do I shim the lens?

 

[Samuel Hotton]

I would first check to insure that the measurement scale on the focus knob matches the rangefinder at near and far distances. For the close distance use a measuring tape for accuracy and for infinity make sure the distance is over 105 meters. IF the distance scale matches the rangefinder image, and IF the groundglass image is still focusing behind the target then you must shim the lens forward. First you must make sure the scale and rangefinder match by using the two adjustment screws on the top of the camera under the leatherette on the left hand side. If these match and you decide to shim the lens, you will NEED a special tool to remove the lens retaining ring found inside the camera body. IF you DO NOT have this tool DO NOT use a pair of scissors or two screwdrivers you stand a GREAT risk of cutting/tearing the bellows or slipping and scratching the lens. The ring is unscrewed counter clockwise, the lens is removed from the front. Washers can be cut from milk carton, paper, brass shim stock, beer cans to acheive the thickness required to fit over the back of the lens mount to move the lens physically forward in the required amount to bring it into focus to match the scale and rangefinder. It is a trial and error process that requires time and patience to get it correct and NOT damage the camera. I've had to add .034 inch of shims to bring mine into focus. Yes the Bessa CAN focus sharply WIDE OPEN and at MINIMUM distances, it only requires a gentle touch, great patience and the CORRECT tool for removing the lens flange.
I hope this helps,
Sam H.

 

[Rol_Lei Nut]

Accuracy *should* be at least very good, if not absolute, certainly much better than what you are getting.

Many different types of rangefinder adjustments exist.
Some have separate (though interacting) adjustments for infinity and close range.
Unfortunately I've never opened the E-M Bessa up (I'm very slowly restoring it, fine adjustments are still way in the future).

Try:
http://www.kyphoto.com/cgi-bin/forum/discus.cgi
Lots of very competent repair people there