Carl Zeiss Jena Sonnar 50/1.5 LTM focus shift

[anindyo]

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Hello,

 

Could anyone using CZ Jena Sonnar 50/1.5 share your experience regarding focus shift?

I got mine in less perfect condition: stiff focus ring and focus shift, unable to focus at infinity wide open. Use it with Leica LTM to M adapter on M8.

 

I brought it to local repairman, but he could only make the focus ring turns a bit smoother. Thus I am wondering, is focus shift just a "normal" behavior of this lens?

Have been digging internet about this issue but seems most people talked about the sonnar ZM version.

 

Thanks.

[Guest Her Berger]

Same to me. I had a brandnew ZM 1,5/50, completely out of range on my M9.
It's a great lens, indeed, works fine adapted on Fuji X pro with LiveView.
Traded it for a 2,8/25 ZM for my M8.2
 

[DwF]

I just got one of these  (for M9) and mine seems to be calibrated at f2.8  I will probably send it in to calibrate for wide open after I live with it a bit.  I find that so far I have been able to "move in" and get focus where I need it for shooting f1.5-2.5. This pic was a grab shot, taken wide-open, while my the way home with the lens. I've taken a couple of casual portraits and so far like the way it renders on the M9. 

[elmars]

The focus shift of the Sonnar is well known. You can have it calibrated on f 2,8 or f 1,5. The newer ones are calibrateted on f 2,8 I think. So You have to adjust the focus manually in an estimated degree if You use the apertures from 1,5 to 2,8. This is possible, but I did not like it, so I sold the lens and am now satified with the Summilux asph (the pre-asph has Focus shift too, but not as much as the Sonnar).

 

Focussing to infinity should be no Problem.

 

Elmar

[Ecar]

I think there is some confusion here: the OP seems to have issues with a CZJ Sonnar in LTM, which is a lens made around WWII, unlike the CZ Sonnar ZM, which is current.

 

All Sonnars do indeed suffer from some degree of focus shift, whether they are vintage or more recent. However, there is no reason why they shouldn't focus to infinity.

 

Also, in the case of the CZJ 50/1.5 LTM, the used market is rife with soviet-era fakes, ie essentially "re-branded" Russian Jupiter-3 lenses. There were relatively few genuine Zeiss lenses made in LTM, the majority being in Contax mount. For anyone interested, the history of the Zeiss brand and manufacturing is worth reading. A picture of the lens could give some indications as to whether the OP's lens is likely to be a genuine one or not. 

[anindyo]

Hi all,

 

Thanks for sharing. I think I have to live with this focus shift issue. I love its rendering and can adapt with aiming slightly out of focus backward on my M8.2. Practically, f1.5 is only used occasionally.

 

What confuse me is that this lens fails to focus at infinity, confirmed using Fuji XE-1. Focus peaking started to appear at f2.8. Will return it to the repairman and see whether he can solve this.

 

@Ecar

Based on internet, mine seems to be original, that's why I feel reluctant every time I was thinking of selling it. Not so sure though, since I'm just newbie.

It use "." instead of "," for the numbers, letter "m", and red T (image below).

 

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[duckrider]

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Hi all,

 

 

What confuse me is that this lens fails to focus at infinity, confirmed using Fuji XE-1. Focus peaking started to appear at f2.8. Will return it to the repairman and see whether he can solve this.

 

Did You check out if the adapter is the reason? These are often too thick some 1/100 mm to get into infinity! Must not nessecerily be the lens.

Thomas

[Ecar]

It definitely looks like it's a proper, battered wartime one.

Bear in mind that the LTM versions were essentially factory-converted Contax mounts. AFAIC, I prefer to buy these (I have a few, both f/1.5 and f/2) and use Amedeo Muscelli's excellent adapters. The post-war Zeiss-Optons, in particular, are to die for... 

In any event, if your lens doesn't reach infinity, chances are the whole focus range is off.

Whilst your LTM to M adapter could be part of the issue, I'd say that it needs a trip to a competent repairman.

If you are located in Europe, I'd send it (along with the adapter) to Will van Manen in the Netherlands. He's a pleasure to deal with and has been able to fix pretty much any lens I've thrown at him.

[menos I M6]

Please be careful not mixing up informations.

 

To the OP with his CZJ 5cm f1.5 Sonnar:

 

This Sonnar design is known for it's large focus shift due to it's optical design.

It also is a lens design with very low contrast at all apertures compared to modern lenses of today.

 

This lens can be set up in different ways, depending on how a user wants to use it most.

Most popular nowadays to set up these vintage lenses is to calibrate it for wide open use (f1.5) close up as it is a lovely portrait lens and delivers a very unique rendering.

 

When this lens is setup to focus spot on on a Leica M rangefinder at close focus (1 - 2 m range), it is absolutely normal that it does not focus to infinity.

The optical design of this lens does not permit that unfortunately.

 

The behavior you describe sounds perfectly normal for such a lens.

Depth of field when shooting at infinity will catch up to render objects at infinity sharp at around f2.8 to f4.

Best used is this lens for critical shots at infinity (landscape, etc) at ~f5.6

 

Another reason why you may see difficulty focussing this lens (especially wide open f1.5 - f2) with electronic viewfinder cameras and focus peaking is it's nature of very low contrast.

This lens is best used on a Leica rangefinder.

 

Make sure to post some photographs here on the forum in this thread:

http://www.l-camera-forum.com/topic/186858-the-view-through-older-glass/

 

Cheers

[Ecar]

You are quite right, Dirk. There was some confusion about the lens type - and now there is some confusion about what the issue actually is...

 

To the OP: despite the stiff focus, does the lens "reach" infinity (ie, do the images overlap perfectly in the rangefinder patch at infinity, irrespective of whether the resulting picture is in focus or not)?

[menos I M6]

Now I also see the photograph of the actual lens in question :-(

It does indeed not look like a genuine CZJ LTM lens.

 

Please be aware that as earlier posts have suggested the time around WW2 was not only very chaotic in terms of the production of lenses but that the circumstances how the Eastern German Carl Zeiss Jena facilities where raided of stock, machines, even employees and a long time after that (into the late 1940's) with a transition of lenses produced from Carl Zeiss stock and more and more Russian produced items, culminating in Russian only lenses.

 

To top this off unfortunately there is a huge market around hacked Frankenstein lenses (made of different mixed components), many of which made up to look like CZJ lenses, sold by unscrupulous sellers as "genuine" Carl Zeiss Jena, where in fact they are not.

 

There are also a few specialists around who know these lenses very well and who have over time resurrected a number of lenses.

 

All in all it is now very, very difficult to find a genuine matching numbers wartime Carl Zeiss Jena lens. The one in the picture above is unfortunately not one of them.

 

A few pointers:

- "C" in Carl Zeiss Jena beauty ring should have more closed ends, not as open as it is

- "s" in Carl Zeiss Jena beauty ring should be more curved

- "r" in Nr in the beauty ring should have a distinct stem from the straight line of the "r" and the bow of the "r" should point towards 5'o'clock (downwards) not to 3'0'clock (to the right)

 

Some differences to the genuine wartime sample I have in the body (pointing towards a Russian body used here in the picture):

- lens in picture has:

- dot as aperture index (CZJ LTM does have a line as an index mark)

- dot as comma in all numbers (CZJ has comma ",")

- missing second screw in focus ring at close focus

- lens focusses much closer than 1m (this could be an indication of a wrong assembly, probably explaining focus issues), genuine lens stops at a little under 1m mark

- distance scale markings are different from CZJ markings

 

Also - the markings in the lens' aperture ring and aperture index ring should have realistically a corresponding equivalent mark on the filter ring of the lens (maybe even a bent filter ring).

If it does not it could be a an indicator of a lens body used with a different optical cell.

 

The lens in question should be examined by a specialist. There are some indicators even in the inner construction and markings of these lenses which make it easy for them to determine the origin of the lens.

Such lenses can have a value when the lens is technically ok and the paid price matches the origin of the lens fairly (CZJ optical cell vs Jupiter optical cell; used lens mount, …).

 

In my opinion, a good, well sorted Jupiter is a better user than a bad or damaged genuine CZJ, but it surely should be reflected in the price one paid, especially at current going rates of genuine lenses.

[anindyo]

about adapter:

I don't think it's the issue. I can focus my summar properly with it.

 

@Ecar:

so, is the Contax version more problem-free? I am currently thinking of sell mine and get the contax version + amedeo adapter. But, who want to buy a lens with problem?

 

The lens can reach infinity/very long distance as indicated by rangefinder patch, but the resulting picture is blurry. Turn the focus ring a bit more at maximum (slightly more past infinity mark), the picture is slightly better but still appears out of focus.

 

 

@Dirk:

Thanks for enlighten me with lots of new information.  

I just had a chat with my repairman and his explanation about infinity focus at wide-open is pretty much in agreement with yours. Many online discussions about Sonnar that I read mentioned focus shift, but I can't remember anyone pointed focus problem at infinity. Feel better knowing that it may be just a normal behavior.

 

I'm aware that the really genuine one is very hard to find, so I decided to take a gamble. It was priced much cheaper than secondhand Sonnar ZM anyway. But, if focus shift is already part of Sonnar character, overall this lens isn't that bad, is it?

 

Below some samples from random walk around with this lens on M8.2, as I remember at f2. Hopefully, despite its flaws, it still renders the original Sonnar look   

 

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Now I'm contemplating whether to keep this lens or get the contax version + adapter...

[Ecar]

Based on your explanations, I think that the focus shift inherent in the Sonnar design is probably made worse by a lens that cannot be properly adjusted.

The battering (or perhaps "butchering"...) that it has gone through may indeed mean, as Dirk suggested, that it was assembled from different components that cannot be made to work together.

A J-3 can, to some extent, be adjusted (or at least improved) by "shimming", ie adding shims to slightly adjust the position of the optical cell inside the mount to compensate for a native focal length that is slightly off the Leica standard. Depending on the original construction of the lens, this can sometimes not be done. FWIW, I have two J-3, only one of which could be calibrated satisfactorily.

Regarding Contax mount sonnars, I have never come across a fake. This doesn't mean they don't exist, but it's safe to assume that if there are any, it's likely a small number. Again, I'd recommend a later Zeiss-Opton (cleaner image, due to better coatings I guess) over a CJZ. 

Bear in mind that the Amedeo adapter itself is rather expensive (although his most recent, 50mm-only version is somewhat cheaper). 

 

Nice pictures, btw.

[menos I M6]

Nice pictures with the lens in question. I am a big fan of Sonnar lenses and in my opinion any good sample of a Sonnar is a great one, no question the heritage.

 

One thing with classic German and Russian Sonnar 50mm lenses to be aware of is that there are many different variations, both from the German factory and from the chaotic years of Russian production from German stock, mixed with Russian components and later entirely Russian parts.

 

During that time there where different standards these lenses where made for (in general the standard we like to use today to adapt these lenses to Leica digital cameras was an exception - both the lenses designated for the Contax cameras and later lenses made to be used on Russian cameras differ from that specific standard).

 

There are some lenses, made for Contax mount that can be modified, some cannot (the focal length does differ and on the samples that cannot be modified to spec there is simply not enough adjustability to the focal length possible in the optical cell).

The same is true for Jupiter J-3 lenses.

Some samples can be successfully modified, some cannot.

 

In order to modify a Sonnar lens not designed to be used for the Leica rangefinder it is most often not enough to simply adjust the distance of the optical cell to the film plane (often simply called "shimming", as this is often done simply by varying shims between optical cell and focus mount).

It is in most cases also necessary to alter the focal length of the optical cell by moving the rear group.

 

The reason why genuine Carl Zeiss Jena lenses in Leica LTM mount are so pricey lies not only in the fact that these where produced in smaller numbers than Contax mount lenses (and especially later Jupiter-3 lenses), but in the fact that these lenses are made in the factory with both a different focal length and a matching lens mount, calibrated to the Leica rangefinder coupling.

 

During production of these lenses something very similar was done as in later Leitz lens production - optical cells were manufactured and tested.

Optical cells that fell into different focal lengths were sorted and marked designated to be best used for the respective standards.

Parallel focus mounts would be produced and likewise measured and then matched to best fitting optical cells.

 

This is how it came to be that all genuine Carl Zeiss Jena Sonnar lenses in LTM mount have matching serial numbers in front beauty ring, internal of optical cell and focus mount.

Lenses missing this match have been modified outside of the regular factory production.

 

If I were looking nowadays for a genuine lens, the first place I would look would be the small community of collectors and users - every now and then a lens will change hands. One has to be patient.

It took me several years (and a few misfortunes myself) to find a good sample.

 

Ebay or alike are NOT good sources for such lenses, only exception being sales from reputed dealers.

 

Still today the easiest way to get to a classic Sonnar look is simply finding one of the Japanese Sonnar lenses from Nikon or Canon, made in the 1950's.

These (although also not without their specific issues) are generally very, very nice lenses - my personal favorite here the Nikkor 5cm f1.4 LTM.

They do render entirely differently though from a genuine pre war or wartime Carl Zeiss Jena Sonnar (different optical design, different glass types and especially entirely different coatings).

The Japanese manufacturers also took design routes to improve the Sonnar design with further optical corrections (a compromise, reducing some of the characteristics of the Carl Zeiss Jena Sonnar rendering, specifically how sharp detail, contrast and smoothness are concerned).

 

For these reasons, a good copy of a CZJ Sonnar is something very special - a really good and well sorted J-3 is no slouch either though.

I think the Amedeo adapters are fantastic - their main purpose though is to be able to use lenses from different systems on a Leica M.

It is not really a good solution to buy an Amedeo adapter and a Contax mount Sonnar just to use it on a Leica M - except of course that Contax mount Sonnar comes with a good working Contax camera body ;-)

 

A LTM Sonnar has the advantage of being compact and light (especially the wartime aluminum bodies lenses) and have aperture and focus control on the body without rotating the entire lens.

 

Lenses that are faked most often are war time Carl Zeiss Jena Sonnar 5cm f1.5 as there is so much Russian parts and lenses on the market that can very easily clobbered into a lookalike lens.

I feel tough that this market has settled a bit as people have found that good copies of the Russian made J-3 are very nice users as well, having elevated prices on those lenses on the market.

Until just a few years ago one could buy a solid J-3 for no more than 50 USD - those times are long, long over now.

[farnz]

I have several war-time Sonnars (some CZJ from the Russian factory in Jena and some Zeiss Opton from the German factory in Oberochen) and I agree with everything that Dirk has written above.  If you decide to find a Contax mount Sonnar and an Amadeo adaptor make sure that you get the adaptor for Contax lenses and not the one for Nikkor lenses because the Nikkors and Contax's had a slightly different pitch in the focussing helicoid.  Nikkor lenses will fit the Contax adaptor and vice versa but your focussing will always be slightly off and you might (wrongly) start to doubt your technique.  The Amadeo Contax adaptors are engraved with a "C" and the Nikkor adaptors with a "N" but you have to look closely to find it.  If you buy directly from Amadeo in Venezuela he sometimes has difficulty with government officials holding onto his exports for a while for no particular reason so you need to be ready to wait patiently.

 

If you do manage to find a good, genuine 50/1.5 or 50/2 CZJ Sonnar or Zeiss Opton Sonnar then the rewards are worthwhile and the lenses will offer a low contrast, high acutance signature with vivid colours and smooth, even bokeh that's not available in another lens.   Canon and Nikkor copied the Sonnar and made very good lenses but I prefer the signature of the bona fide Zeiss lenses (YMMV).

 

Pete.