Old Thambar f=9 cm 1:2,2 found -> cleaning?

[stevemark]

Advertisement (gone after registration)

Hello to everybody

 

I'm new at the leica forum - up to now my only practical experience with Leicas was my mothers "Leica III", equipped with a simple Elmar 3.5/ 50mm. I did use it at the age of 15 in school ... to take pictures of the girls . - That's how i came into photography. At the age of 17 i changed to Minolta (Leitz was simply too expensive for me), and i never used the Leica III any more.

 

Some days ago, however, i found a Thambar 9 cm 1:2,2 at a local "garage sale". When i saw it, i thought it might be nice as a portrait lens, even though there was some fungus inside. Otherwise the glass was without any damage. I decided to buy it, since it was just about 100$.

 

Now my question: Does anyone here know how to dismantle / clean the Thambar? Before starting the work, i'd like to collect as much information as possible ...

 

Thanks for any help, drawings (eg lens cross-section) and suggestions.

 

Stephan

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[Geolux]

Stephan:

Congratulations to you . Finding a Thambar Lens is most fortuitous. They are exquisitely rare. The $100.00 you say you paid is just a pittance compared with the more realistic value of several thousand dollars, assuming the lens is complete and in decent condition. For the moment, don't worry about the fungus. Fungus mostly affects the optical performance of very short focal length lenses. Again, this depends on the extent of the fungus. Many decades ago, one of the lens workers at Leitz told me that dismantling the optics of a Thambar is exceptionally difficult, and in some cases, impossible, because, during manufacture, the metal mount is "spun around the glass, meaning that the metal is actually bent and formed around the glass. Your lens is most likely not coated, although a few were coated years after manufacture. I would strongly urge you to try using the lens without trying to remove the fungus.

 

The Thambar Lens is a 90mm f/2.2-2.3 screw mount lens. The complete lens consists of the lens and focusing mount, a separate screw-in glass disk with a mirrored spot in the cneter, and a hood. It is important to understand that the screw in glass disk is NOT a diffusion disk. It is actually a screw-in attachable central stop. You will note the lens has two different aperture scales, one in white and the other in red. The scale beginning with f/2.3 is used when the central stop is screwed in place.

 

The Thambar Lens is a variable or adjustable softness lens that provides a "sunny" appearance" in the final result. The "sunny appearance" is due to the flare of highlights into the shadows caused by the deliberately engineered spherical aberration in the periphery of the lens. The central stop cannot be used below f/6.3, where the critically sharp part of the lens begins.To some extent, results seem to be dependent on the type of film used. My experience seemed to result in slightly more flare when Tri-X film was used, as opposed to slower films. Also, my experience is that better results are obtained in black and white, rather than color, although this can be just a personal preference.

 

There is much more about this lens, but for the moment, I strongly suggest that you do not try to take the lens apart. If the focusing mount is very stiff, it might pay to have the mount cleaned and relubricated. However, make sure the person doing such work is highly competent and experienced. Just use it and see what happens. You might be pleasantly surprised.

 

I have owned several Thambar Lenses, and to this day, I still have one that is in superb condition, and I occasionally trot it out and use it for real photography. I use it with a screw-bayonet 90mm adapter on an old M camera, and yes, I still use the very old Leitz reloadable brass film cassettes.

 

Again, congratulations, and enjoy a wonderful lens

 

George

[jc_braconi]

Now my question: Does anyone here know how to dismantle / clean the Thambar? Before starting the work, i'd like to collect as much information as possible ...

 

Thanks for any help, drawings (eg lens cross-section) and suggestions.

 

Stephan

 

If you really need to dismount the focusing mount to clean and lubricate take care to refer the two parts when they come separated. as it is a multiple thin threads.

I found one with a thin, home made "washer", because the owner was not able to find the good threads.

(Using a M8 it is more easy to use a try and error system).

Edited May 27, 2011 by jc_braconi

[robert_parker]

I'm pleased to say so far I haven't had a lens with fungus (though I had one false alarm where it transpired I was looking at a bit of 'separation' in the lens elements ) but when researching it I found that increasingly there are techniques being developed which do not involve the dismantling of the lens, for instance using UV light, sunlight, or even radiation .

 

In England, the weekly magazine Amateur Photographer has produced a short but infromative article on this in their Saturday 21st May 2011 issue, which is likely to be still available.

 

I would nevertheless agree with Geolux's highly informed comment that dismantling a lens of this type is best left to a highly skilled repairer or technician

[stevemark]

Stephan:

Congratulations to you . Finding a Thambar Lens is most fortuitous. They are exquisitely rare. The $100.00 you say you paid is just a pittance compared with the more realistic value of several thousand dollars, assuming the lens is complete and in decent condition.

I knew the lens name and the "Thambars" place in lens history - but I didn't know its rarity when i bought the lens, to be honest ... Since i am quite interested in lens history and portrait lenses in particular, i just had the idea to compare the Thambar with two other classics, namely the Zeiss Sonnar 2/8.5 cm and the Zeiss Biotar 1.5/75mm. Should be a nice small project, but i don't the two other lenses yet ... Anyway, i am certainly happy about the Thambar (which had the spot filter, but no lens hood included). Apart from the SLIGHT fungus there is also a little haze (but definately nothing dramatic), and a few very tiny scratches/cleaning marks. The lens certainly is not in perfect state, but definately quite usable.

 

 

For the moment, don't worry about the fungus. Fungus mostly affects the optical performance of very short focal length lenses. Again, this depends on the extent of the fungus. Many decades ago, one of the lens workers at Leitz told me that dismantling the optics of a Thambar is exceptionally difficult, and in some cases, impossible, because, during manufacture, the metal mount is "spun around the glass, meaning that the metal is actually bent and formed around the glass. Your lens is most likely not coated, although a few were coated years after manufacture. I would strongly urge you to try using the lens without trying to remove the fungus.

Thanks a lot for this information! Sounds reasonable .

 

The Thambar Lens is a 90mm f/2.2-2.3 screw mount lens. The complete lens consists of the lens and focusing mount, a separate screw-in glass disk with a mirrored spot in the center, and a hood. It is important to understand that the screw in glass disk is NOT a diffusion disk. It is actually a screw-in attachable central stop. You will note the lens has two different aperture scales, one in white and the other in red. The scale beginning with f/2.3 is used when the central stop is screwed in place.

Yes, i knew that before - i always was interested in portrait lenses with residual spherical aberrations ... that's why i knew the Thambar name ... BTW lens and focusing mount are both marked with a hand-written (in fact: hand-scratched) tiny "19750 FR54" (only visible when separating lens and focusing mount) - any hint what this could mean?

 

The Thambar Lens is a variable or adjustable softness lens that provides a "sunny" appearance" in the final result. The "sunny appearance" is due to the flare of highlights into the shadows caused by the deliberately engineered spherical aberration in the periphery of the lens. The central stop cannot be used below f/6.3, where the critically sharp part of the lens begins.To some extent, results seem to be dependent on the type of film used. My experience seemed to result in slightly more flare when Tri-X film was used, as opposed to slower films. Also, my experience is that better results are obtained in black and white, rather than color, although this can be just a personal preference.

Thanks a lot for these practical hints. That's pretty much what I expected from my personal experience as well, using Tri X and lenses such the Minolta MC 1.7/85mm, the Minolta AF 1.4/85mm for portraits, e. g. of the Dalai Lama some years ago.

 

There is much more about this lens, but for the moment, I strongly suggest that you do not try to take the lens apart. If the focusing mount is very stiff, it might pay to have the mount cleaned and relubricated. However, make sure the person doing such work is highly competent and experienced. Just use it and see what happens. You might be pleasantly surprised.

Thanks again - yes, i will not dimantle the lens body; the focus mount works reasonably well and doesn't need immediate attention. And yes, I certainly will use the lens. At first I'll mount it to my Alpha 900 and use it for some macro / flowers; these images should give me a general idea of how the lens works and reacts to certain situations.

I have owned several Thambar Lenses, and to this day, I still have one that is in superb condition, and I occasionally trot it out and use it for real photography. I use it with a screw-bayonet 90mm adapter on an old M camera, and yes, I still use the very old Leitz reloadable brass film cassettes.

Congratulations as well ... yes, the M-adapter was included as well, but no M-Leica ... and some weeks ago i found one of these ancient brass cassettes as well.

 

And yes, there was a near-perfect Leica IIIf with a perfect, coated Summitar 2/50mm as well, at the same place. I bought it, since the original Lica III of my mother is in a - sad to say - nearly unusuable shape.

 

Again, congratulations, and enjoy a wonderful lens

 

George

Thanks again for you help; I certainly will post some images, but expect a few days delay until i have really time to do things properly.

 

Stephan

[stevemark]

...

but when researching it I found that increasingly there are techniques being developed which do not involve the dismantling of the lens, for instance using UV light, sunlight, or even radiation .

 

In England, the weekly magazine Amateur Photographer has produced a short but infromative article on this in their Saturday 21st May 2011 issue, which is likely to be still available.

 

I would nevertheless agree with Geolux's highly informed comment that dismantling a lens of this type is best left to a highly skilled repairer or technician

 

Since i am analytical chemist myself, fungus for me i a sign that there is "some food" for mould. Actually spores are nearly ubiquitous, mould can't grow simply "on air and water". Actually lubricants (composed of fats and special soaps, e. g. lithium or barium soaps) "separate" over time, and the fats move along the surfaces, including glass surfaces. This will cause "haze" and may later cause "fungus" if the soap is not too toxic for the spores to grow.

 

Therefore i think that "killing" the fungus with UV or gamma radiation would just be a temporary solution. More important would be the removal of the thin fat/soap layer on the glass surfaces! This removes the "haze" as well as the potential "food source" for the fungus. The optical performance of a lens will increase remarkably when the haze is removed; contrast is raising dramatically, and purple fringing is reduced visibly. I did it recently with a Zeiss Biotar 2/58mm (M42)...

 

Stephan

[stevemark]

Advertisement (gone after registration)

One of the first images using the Thambar on my Sony A900 - the lens was used wide open, but without the center-spot filter. The "weird" bokeh and the strong spherical aberrations create a look which really is unique. I am sure it cannot be reproduced with any other lens. The later "soft" lenses have sperical aberrations as well, but a much "better" (calmer) bokeh. The simple "softeners" (either softars froms Zeiss or the Minolta ones) are quite different as well, let alone software based manipulations.

 

I have added two additional photos of the same flower, one taken with the Minolta/Sony AF 2.8/100mm Macro, the other with bokeh-optimized Minolta/Sony 2.8[T4.5]/135mm STF ("Smooth Trans Focus"). The STF gives an extraordinary smooth and 3D-looking background blur; it is a hidden jewel for wedding- and portrait photographers.

 

I will certainly go on using the Thambar

 

Stephan

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Guest #12]

...The "weird" bokeh and the strong spherical aberrations create a look which really is unique. I am sure it cannot be reproduced with any other lens...

 

Thanks for the sample; I hope you can maybe share some portraits in the future.

 

I think you can get the same effect from the Rodenstock Imagon of the same era.

 

I wish I had found that lens!

[stevemark]

Thanks for the sample; I hope you can maybe share some portraits in the future.

I will certainly do some portrait work - since I have no M9, i'll have to use the IIIf. I'll compare the Thambar 2.2/90mm with the Sonnar 2/85mm and - maybe - the Biotar 1.5/75mm. All three lenses were calculated in the 1930's, and it's certainy interesting to see these well respected constructions unified in a small historical "shooting".

 

 

I think you can get the same effect from the Rodenstock Imagon of the same era.

Really? I mean the strange visual effects of the Thambar come from the combination of

1) soft characteristics / under-corrected spherical aberrations

2) the "bad" Bokeh (backgrond-blurring as circle, similar to a mirror lens)

 

Modern "soft lenses" such as the Minolta MD 2.8/85mm SoftFocus and the Minolta 2.8/100mm SoftFocus have

1) variable soft charateristics

2) a "good" bokeh

 

The result is quite different from the Thambar - for practical use I clearly prefer the Minoltas, but the Thambar results are very unique and usefuls in some situations ...

 

I wish I had found that lens!

Yeah, it came to me as REAL surprise ... the first time in my life that such a thing happened

 

Greez, Steve

 

BTW the Minolta-images shown above are NOT from the Minolta Soft-focus lenses - that's another story NOT shown here! The 135mm SFT shown above just has a perfect bokeh due to its patented "Apodisation Filter" (essentially a lens with gradual darkening towards the edges)

Edited June 6, 2011 by stevemark

[davidlockeroy]

Hi... The images shared are very nice. I will also try with the same model of the camera and will post my pictures.

[jaapv]

In the latest LFI there is a rather nice article on the Thambar. The value is put at about 4000$ btw...

[kanzlr]

very interesting samples. thanks.

 

And the STF is amazing. There is a guy who converts them to AiS for use on Nikon bodies...almost bought the STF just for conversion...but I think I am better off just getting a cheap used A900 for the STF

[thrid]

Congrats, that is a rare and very expensive lens you found. I would advise against working on it yourself and would send it to a professional. Where are you located?

[pico]

Wow, what a find! Congratulations.

 

Soft focus lenses are a specialty unto themselves with many different characteristics. I'm pleased to meet another person who appreciates that. I've a couple Imagons, pre-1900 soft-focus (and variable aberation) lenses, and a couple fast lenses that have interesting qualities.

 

Here's one that at least one gentleman here really does not like, but I do.

http://www.digoliardi.net/pampas-grass-1-web.jpg

 

Unfortunately, I blew the focus by a millimeter or two.

 

Oh, and that Summitar if it is coated and has a round aperture (10 blades), then it's probably a real keeper, too.

[luigi bertolotti]

It's really a lens which can give VERY unusual pics...

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[jpattison]

Luigi,

Do you have the centre spot filter?

 

If so, could you please show the same subject taken with and without it, at f2.2?

 

Thanks,

John

[luigi bertolotti]

Luigi,

Do you have the centre spot filter?

 

If so, could you please show the same subject taken with and without it, at f2.2?

 

Thanks,

John

 

Yes, taken with spotfilter on, not fully wide open (f 2,4) : I haven't a couple of pics with filter on+off... probably (have to find those set of pics...) have some couple in very different settings (wide open filter on + closed around 11 filter off)

[M9reno]

See:

 

LeicaShop Vintage Cameras | Leica | Leica Schraubobjektive | Thambar 2,2/90 | Thambar 2,2/9cm | german

 

Thambar for sale: price 4,500 Euros. "Two small fungus spots on front lens element". (Perhaps this says something about the difficulty of repairing this lens? Also, I was under the impression that fungus spreads easily to other equipment - presumably not a concern in this case?)

 

Congratulations on your find ans best wishes!

[Advertisement]

Hallo,

Look here: Interesting Leica gear

[dkCambridgeshire]

See:

 

LeicaShop Vintage Cameras | Leica | Leica Schraubobjektive | Thambar 2,2/90 | Thambar 2,2/9cm | german

 

Thambar for sale: price 4,500 Euros. "Two small fungus spots on front lens element". (Perhaps this says something about the difficulty of repairing this lens? Also, I was under the impression that fungus spreads easily to other equipment - presumably not a concern in this case?)

 

Congratulations on your find ans best wishes!

 

If that was the case the dealer would not have the lens included with his stock. There's a lot of 'old wives' tales' circulating about lens fungus. Fungus spores are everywhere so can attack any lens which offers the right habitat.

 

Some lenses are very difficult to dismantle or the lens elements are very difficult to separate. Dismantling a Thambar might be extremely difficult. I was considering buying one which needed internal cleaning but a respected lens technician advised against attempting dismantling for fear of damaging the lens elements. IIRC this was something to do with the way the lens elements are mounted which makes dismantling risky. And this might be why a dealer may not attempt to have a Thambar cleaned.

 

I doubt if 'fungus' in a Thambar lens would have much of a detrimental effect on performance - in fact if the fungus gets worse it might even add something to the already soft image!

 

And from what i have read about the subject, the fungus can be killed by exposure to UV light - it will not 'disappear' but it will be stopped in its tracks and cease to do further damage.

 

dunk

 

dunk

[someonenameddavid]

I tried looking this up on the wiki, to no avail: what lens formula is the Thambar? Is it a Tessar-type?

 

David