Please teach me about Zeiss Tenax

[MFstooges]

I understand that Tenax I came into production after Tenax II but other than interchangeable lens on the II are there any other features that justify the 10X used market price on the II vs I?

 

[ant!]

The II has a rangefinder, the I not. Also, the II has better lenses (Sonnar, Tessar), better shutter, and more rare.

 

[ph]

I found that the tenaxII delivered sharp enough pictures even if produced at the end of the 1930ies. The winding and distance levers were easy to use when operated a few times and provrided that the little viewfinder window fastened to the lens was clean, distance measurement was easy enough (although not up to M3 standards). A commercial developer surprised me by being able to print the 24x24mm pictures and the 36pictures film roll got 50 exposures

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[MFstooges]

The II has a rangefinder, the I not. Also, the II has better lenses (Sonnar, Tessar), better shutter, and more rare.

So the I is a zone focus camera?

 

[ant!]

So the I is a zone focus camera?

Correct.

 

[MFstooges]

Correct.

So it seems the mechanical design of the Tenax I is about the same as Taxona?

 

[ant!]

So it seems the mechanical design of the Tenax I is about the same as Taxona?

Also correct, the Taxona is just a renamed version after the war, see http://camera-wiki.org/wiki/Tenax_I

 

[JPD]

Interesting information (in German): https://zeissikonveb.de/start/kameras/taxona.html

Scale focusing shouldn't be that difficult with a 37,5mm lens stopped down a little. I have looked at photos taken with the Tenax I/Taxona posted on Flickr, and they seem to often have a problem with vignetting.

 

[MFstooges]

Interesting information (in German): https://zeissikonveb.de/start/kameras/taxona.html

Scale focusing shouldn't be that difficult with a 37,5mm lens stopped down a little. I have looked at photos taken with the Tenax I/Taxona posted on Flickr, and they seem to often have a problem with vignetting.

Did Zeiss cheap out on the lens? I assume with less area recorded on the film they can crop out the vignetting

 

[JPD]

Did Zeiss cheap out on the lens? I assume with less area recorded on the film they can crop out the vignetting

Maybe it's mechanical vignetting at large apertures.

Some examples I found on Flickr:

 

[ph]

I put a classic snap-on sunshade on it since the uncoated glass is not well protected from stray light by its mount.

Lacking a suitable mount I cannot subject the Sonnar to testing on my short mount 24x36 camera in order to judge its illuminated field

Mechanical vignetting does not look as if it might be due to the mount of the Sonnar, although it has a central shutter. I will fish out the negatives and look for darkeneed corners.

However, no reason to believe that Berteles lens construction or Nerwins 24x24 format was chosen to save money on the optics:. Centering the cemented triplet at that time must have required extreme precision and was not a cheap alternative.


p.

 

[MFstooges]

Maybe it's mechanical vignetting at large apertures.

Some examples I found on Flickr:

Upon googling around I found that Taxona has a varian with Tessar 37.5 mm and Novonar 35 mm lenses. The Tenax I is equipped with Novonar lens and the pictures that I found are not very good. The highlight bleeds and causing low contrast image. The sharpness is also not good. However, your sample there seems to be quite sharp so they may come from the Tessar Taxona.
I still don't quite understand why Tenax I needs to have retractable framing window while Taxona can have simpler fix window design.

 

[ph]

I had a close look at my sonnar snaps. No trace of vignetting. BUT I do not normally use lenses wide open in the middel of the day so there may not be any f:2 examples among my pictures with that camera. It is not clear whether the vignetting examples stem from Tenax I with the cheaper lens or from the II version-

p.

 

[JPD]

I had a close look at my sonnar snaps. No trace of vignetting. BUT I do not normally use lenses wide open in the middel of the day so there may not be any f:2 examples among my pictures with that camera. It is not clear whether the vignetting examples stem from Tenax I with the cheaper lens or from the II version-

p.

The Sonnar looks like a normal Sonnar while the Tessar on the postwar Tenax I/Taxona sits much deeper in the mount, so I don't think the Tenax II had the same problems with mechanical vignetting.

Upon googling around I found that Taxona has a varian with Tessar 37.5 mm and Novonar 35 mm lenses. The Tenax I is equipped with Novonar lens and the pictures that I found are not very good. The highlight bleeds and causing low contrast image. The sharpness is also not good. However, your sample there seems to be quite sharp so they may come from the Tessar Taxona.
I still don't quite understand why Tenax I needs to have retractable framing window while Taxona can have simpler fix window design.

On Flickr one member's photos with the Novonar equipped Taxona look like a soft filter was used. Maybe a problem with the second lens element or some oil that has evaporated and "coated" lens surfaces. There are others with much sharper Novonar photos, good enough for small prints for the photo album. The folding Newton finder on the Tenax I made the camera compact, but it fell out of style in the 50s.

One camera with bad finder design is the Super Dollina:

 

[MFstooges]

The Sonnar looks like a normal Sonnar while the Tessar on the postwar Tenax I/Taxona sits much deeper in the mount, so I don't think the Tenax II had the same problems with mechanical vignetting.


On Flickr one member's photos with the Novonar equipped Taxona look like a soft filter was used. Maybe a problem with the second lens element or some oil that has evaporated and "coated" lens surfaces. There are others with much sharper Novonar photos, good enough for small prints for the photo album. The folding Newton finder on the Tenax I made the camera compact, but it fell out of style in the 50s.

One camera with bad finder design is the Super Dollina:

So I acquired a Tenax with Novonar and can confirm the vignetting. Furthermore it seems to have lower contrast when shooting outdoor in bright light except when under the shades or when the sun is behind me. I suspect internal reflection between lens element or could also be something that I did wrong when cleaning the lens. Now between Taxona Tessar 37.5 mm F3.5 vs Robot's Xenon 40mm F1.9 which one has better potential?

 

[JPD]

So I acquired a Tenax with Novonar and can confirm the vignetting. Furthermore it seems to have lower contrast when shooting outdoor in bright light except when under the shades or when the sun is behind me. I suspect internal reflection between lens element or could also be something that I did wrong when cleaning the lens. Now between Taxona Tessar 37.5 mm F3.5 vs Robot's Xenon 40mm F1.9 which one has better potential?

The Taxona with Tessar has the same sunken front element, but I guess the vignetting depends on the aperture used. Some photos on Flickr have vignetting and some don't. The Robot shouldn't have the same problem, but be sure you get a later one that takes normal 135-film.

 

[Sergey Ko]

Tenax I was excellent. I played with it for several films. It was excellent even with Novar lens, but some guy from rangefinder forum said with Tessar is much better.
Here are examples & my camera picture:

 

[MFstooges]

The Taxona with Tessar has the same sunken front element, but I guess the vignetting depends on the aperture used. Some photos on Flickr have vignetting and some don't. The Robot shouldn't have the same problem, but be sure you get a later one that takes normal 135-film.

Oh yeah you're right. Even the newer robot will need special take up cartridge. Such a turn off.

 

[MFstooges]

Tenax I was excellent. I played with it for several films. It was excellent even with Novar lens, but some guy from rangefinder forum said with Tessar is much better.
Here are examples & my camera picture:

Yours don't seem to have vignets. Here are mine.
These are from Ilford FP and I had few of them printed to 8X8 to my satisfaction. Grainy but still acceptable. The greatest thing is that I can get 50-52 frames from 36 exp film.