Voigtlander Zoomar

<p>I have recently purchased a Voigtlander Zoomar lens (36-82mm, f/2.8) for the old Bessamatic. It's primarily for show as a collection piece.<br /> <br /> But, I've noticed a slight greenish tint when viewing with this particular lens. Other lenses are fine and thus the Bessamatic is not the issue. <br /> <br /> Is the greenish tint caused by something due to age? Fungus? Or is this due to smoke/fire? I have no clue.<br /> <br /> Is there any means to having this internally cleaned/repaired? I've looked through the lens and see no other form of distortion or fungus. The focusing is excellent and there are no flaws with the mechanical parts of the lens. Shutter operates fine...<br>

If this lens was used in color photography, the hues would be off target. And if B/W, then there would be a contrast issue.</p>

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<p>The Zoomar does not have a colour cast under normal conditions, so it could be evaporated grease on the elements. I would be cautious about having this lens repaired. Getting the optical element centration right is quite tricky and it would take a very good technician with good equipment to make it perform as it should.</p>

<p>I repaired one about twenty years ago as a favour for a friend and it took me three weeks of working on it, testing (collimator, projection, MTF, film), making notes and putting it aside, having another go, before I got to the point where I felt the performance at the centre, long and short ends was balanced up to the point of being reasonable. It is a very old design, a complicated optic with adjustments everywhere. It's a bit soft at the edges wide open at all focal lengths. Chromatic Aberration is an issue. Don't expect it to perform like a modern Canon L zoom!<br>

I was working on lenses like the Taylor Hobson 25-250 at the time and found my inability to adjust out all the errors in this old lens confusing and irritating. It's an interesting collectable, but you could end up spending some real money to get it right.</p>

<p>It's a fascinating lens, and a bit of history too, being the first zoom for a still camera. The yellow -greenish tint that you refer to is actually radioactive decay of the rare earth elements, not sure if they used thorium or lanthanum in the Zoomar.<br>

Lots of manufacturers around that time used this sort of glass, and the decay causes a green-yellow shift in the colour of the glass. Certainly no problem if you shoot B&W, saves on a yellow filter! You can reduce or even eliminate this colour by exposing the lens to strong UV (sunlight) for a few days, I have left mine as it is, I just take B&W.<br>

As Peter has stated, it is a bit soft overall, but not bad really, and at 2.8 is very fast for a Zoom, even by today's standards.</p>

Wow .. quite a rare lens indeed. There's quite a lot on Voigtlander lenses here.

http://www.taunusreiter.de/Cameras/Bessa_RF_histo.html

Some info is in German

<p>Tony, Peter and Chuck, <br /> <br /> Thank you so very much about the information. The tint in the lens is a slight green, noticeable when changing from other glass such as the refit Retina-Xenar f/1.9 lens or the standard Voigtlander Color Skopar f/2.8.<br /> <br /> I bought my first Voigtlander Bessamatic in 1967, having to save up as a young teenager, mowing lawns, selling newspapers and a TV guide route, and shoveling snow out of driveways. It took me nearly a year to buy the layaway camera.<br>

Since that time, I used the Bessamatic and Zoomar lens to shoot all sorts of high school events such as sports, theater, and candids. It's a great camera. It's now a wonderful collector's camera system and delight in remembering the days of old.<br /> <br /> I sold off some of my camera system back in the mid-70's in favor of the Olympus OM system. I kept Bessy, but sold off many of the lenses such as the Zoomar. Now, that I'm much older, I have this inner urge to collect and relive memories through other Voigtlander lenses. Currently, I'm looking for the 350mm lens.<br /> <br /> I've converted the Retina-Reflex mount lenses to the Voigtlander. The Retina-Reflex IV is part of my collection and all lenses between the two makes are interchangeable.<br /> <br /> Again, thank you very much for the information.</p>

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<p>Hey there. I had one of these that was missing the mount. It does indeed have a thorium element that the contamination meter in my lab easily picked by the counts over background.<br>

As the thorium decays, the high energy particles cause defects to form in the matrix of the glass. These defects eventually make the glass take on a yellowy-tea colour. People have found they can "anneal" the defects in the glass by exposing it to UV rays.</p>