Adjusting rangefinger for Werra Matic (Carl Zeiss Jena)

[deontic]

Hi,

I am the lucky owner of a werra matic for which the rangefinder is somewhat off (around 30%). I have removed the top and found the telemeter adjustment screw shown in this diagram:

https://krg.pagesperso-orange.fr/werra/construction.htm

However, there is also a "blocking screw" according to the diagram (to the right of the adjustment screw). Do you know if I need to loosen the blocking screw before adjusting via the adjustment screw? Both screws are quite hard stuck and I am afraid I may break something if applying too much force....

All the best,
Christen

 

[CharlesDAMorgan]

I can't answer the blocking screw question (although I love my Werra 3) but if the screws are hard stuck, use a very good penetrating oil first and don't try anything until it has had a good chance to soak through. Then, in my experience, breaking the screws is much easier....

 

[deontic]

Thanks Charles. I guess I shall (carefully) drip some penetrating oil on the screws. They really are hard stuck and I would hate to breaking them as the camera seems to be in pristine condition after almost 60 years ��.

 

[deontic]

I finally managed to move the screws. The penetrating oil did the trick. And, importantly, as I had expected - to unscrew the "blocking screw" somewhat, and then adjust the rangefinder screw. The screws are different types and the rangefinder adjustment screw is made of a weaker metal. Due to my somewhat hard treatment of it before unscrewing the "blocking screw" it partly broke. Luckily I was still able to move it around with a precision screwdriver.

Not so lucky, I found that the rangefinder is unbalanced. Thus it was impossible to adjust it so that it was correct both on infinite and 0.8 meters at the same time. This was really a disappointment. Now I have adjusted it to be correct for infinity and it is around 10% off for the 0.8 meter. I guess I have to recalibrate manually before shooting close-ups... If anyone is reading this and know whether this is a common problem for Werras, or indeed any other rangefinders from the period, I would be happy for a short comment!

 

[Sanders McNew]

You might want to consider recalibrating so the RF is accurate up close, and off at infinity. Typically, close focusing is critical but infinity usually falls into the hyperfocus range at most aperture settings.

 

[Muggins]

Sanders (there's a blast from the past - I see you've actually been back for a little while, hope the Rollei still gets an occasional outing!) has a point - it's much easier to make up for errors at the infinity end.

It's a long while since I've done the one Werra rangefinder I adjusted, but I have a feeling that, because of the unique design, it will always be slightly out at one end of the range or the other. I suspect that, unlike the shutter, it was designed for simplicity - you'll have seen how little there is under the top plate - and a little bit "off" here and there was considered acceptable.

Please don't ask what the unique bit is, because I can't remember it!

 

[deontic]

Thanks for the advice, Sanders and Muggins! Makes sense on many levels when I consider it more carefully. In addition to being within hyper-focus range, it appears to be less of a percentage off for longer distances.

The question arises though, when adjusting it more precisely at close range (0.8 meters): from where do I measure 0.8 meters? Is it from the start of the lens? From the center of the lens, or from where the light meets the films? On such short distances that difference will itself amount to around 10%... The logical choice would be the latter, I think, but a second opinion on this matter will be much obliged. All the best, Christen

 

[Sarcophilus Harrisii]

Thanks for the advice, Sanders and Muggins! Makes sense on many levels when I consider it more carefully. In addition to being within hyper-focus range, it appears to be less of a percentage off for longer distances.

The question arises though, when adjusting it more precisely at close range (0.8 meters): from where do I measure 0.8 meters? Is it from the start of the lens? From the center of the lens, or from where the light meets the films? On such short distances that difference will itself amount to around 10%... The logical choice would be the latter, I think, but a second opinion on this matter will be much obliged. All the best, Christen

The convention for camera lenses (SLR, Rangefinder, TLR etc) is usually from the film plane. In the absence of any advice to the contrary in the user manual, I would assume it's that. Diopter lens distances, on the other hand, are usually from the front of the lens.
Cheers,
Brett

 

[deontic]

Thanks, Brett. That is good advice.

I have managed to find several user manuals for various Werras online, but none of the original service manuals (if there were any). It is strange due to the peculiarity of some of the Werra solutions and the fact that they sold quite a few around Europe during their heydays, and I’m sure there would be a demand for local repair.

I had my first film (Ilford Delta 100) taken with the Werra Matic in question back from the developer yesterday, and I’m happy to say that I was not disappointed. I was aware of the rangefinder being slightly off and did manual calculations and the result was quite pleasing to a layman’s eye ��.