Recieved a 50 1.5C Sonnar ZM today, samples

furcafe said:
There may be an issue w/Zeiss's QC, as posts from back alley, et al. seem to show that not every Sonnar-C front focuses as much as Steve's example.
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Weird to think that it's quality control. Zeiss went to lengths beyond what almost anyone else in the industry does in terms of QC. They installed Zeiss MTF plotters at Cosina so that every lens could be tested & every one is inspected before it leaves the factory.

Bob Shell, formerly of Shutterbug, posted on the CVUG list recently that Zeiss is fanatical about QC & that their insistence on it led to a very stormy working relationsip with Kyocera during their manufacture of the Contax line. He added that he's heard similar reports of complaints from Cosina that Zeiss is unreasonable in their demands for tight tolerances. I could more readily believe QC problems with the ZI despite the Zeiss QC procedures because Zeiss is not a camera manufacturer, but Zeiss knows lenses & optics. No QC is perfect & even tolerances allow for some sample variability. So, there may be something to it, but I wouldn't expect it to be much of an issue.

A side note on this matter . . . In his reports on the Zeiss lenses, Puts said that he found the Zeiss ZM tolerances to be about half way betwee Leica & Cosina's Voigtlander lenses.
 
xayraa33 said:
hmmm... it sounds like the Jupiter 3 in LTM phenomena.
at close focus, at f1.5 , the lens is not focused where the camera's rangefinder says it is.
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And yet, Krosya, we have xayraa33 saying just the opposite in this quote that I've attached. From his experience with a J-3 Sonnar, he says the reports he's hearing in this thread are classic Sonnar behaviour. A lot of this is in the eye of the beholder, or so it seems to me.
 
Krosya said:
The way I look at this - why would you want to have and pay for a 1.5 lens if you can't really use it fully at 1.5?
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You can use it fully at f/1.5. You just have to ask Zeiss to re-adjust it for that aperture. It was reported earlier in this thread that they have said that they will adjust it to the requirements of the user whether it's f/1.5, f/2, etc. It's just that it comes from the factory optimized at f/2.8.
 
Huck Finn said:
And yet, Krosya, we have xayraa33 saying just the opposite in this quote that I've attached. From his experience with a J-3 Sonnar, he says the reports he's hearing in this thread are classic Sonnar behaviour. A lot of this is in the eye of the beholder, or so it seems to me.
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Well, here it could be a whole different issue - as we all know with russian lenses QC was poor and lenses are sol old - someone could have worked on it and damaged it. I may have a well adjusted one.
 
Huck Finn said:
You can use it fully at f/1.5. You just have to ask Zeiss to re-adjust it for that aperture. It was reported earlier in this thread that they have said that they will adjust it to the requirements of the user whether it's f/1.5, f/2, etc. It's just that it comes from the factory optimized at f/2.8.
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I may have missed some posts, but this somehow doesn't make sence to me. Why would they optimize this lens for 2.8? As a user, I buy a fast lens so I can use it wide open, not at 2.8 or any other setting. And whats this whole thing about sending it back to re-optimize? Why would anyone buy a new lens just to send it back? I can see if they optimized it for 1.5 and for those who wanted it to be optimized at 2.8 - they could send it back. Seems a bit backwards to me. When I buy a lens, a new lens that is - I expect for it to work right, right out of the box.
As far as Zeiss QC - that all may be on paper how they are testing everything and sign before it leaves a factory, but in reality it seems different. For example - not ALL Sonnars have this front focus problem, it seems. Joe's looks fine, as well as some other samples I have seen. So, if ZEISS do have that famous QC - ALL their lenses would behaive the same. They would all either be optimized for 2.8 or all would be optimized for 1.5 in case of Sonnar here. Since it's not so - what kind of QC can we even talk about here? To me its inconsistant - one way or another, so QC is faulty, regardless what f-stop Zeiss says this lens is optimized for.
 
I've yet to see any evidence these threads for a Zeiss QC issue. My Sonnar close focuses as does Steve's but ONLY at the closest focus distance. Were any of Joe's shot at 0.9m?
The close focusing is an issue I'm not happy with and am still mulling over returning it and getting a pre-asph summilux. However, I don't think we should accuse Zeiss of shoddy QC with such limited evidence.
Nick
 
LazyHammock said:
I've yet to see any evidence these threads for a Zeiss QC issue. My Sonnar close focuses as does Steve's but ONLY at the closest focus distance. Were any of Joe's shot at 0.9m?
The close focusing is an issue I'm not happy with and am still mulling over returning it and getting a pre-asph summilux. However, I don't think we should accuse Zeiss of shoddy QC with such limited evidence.
Nick
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Ok, I can go with that. You are right we don't have enough to go by, so to be sure, maybe we need a poll, where everyone who can and want test their Sonnar at closest distance wide open, at 2, at 2.8 and we will see what is happening with this issue. Unfortunately, I don't have this lens or I would start a test thread.
So, anyone is a game to do this?
 
Krosya said:
I may have missed some posts, but this somehow doesn't make sence to me.
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My apologies, Krosya, but the post to which I referred was not on this thread but on the thread titled: "3 ZM Lenses Reviewed." Here's the link:

www.rangefinderforum.com/forums/showthread.php?t=35356

See post #11 from Sebastel on the first page. He's the one who said that Zeiss offered to readjust the lens.

See post #88 from me, on page 6, for the official statement from Carl Zeiss AG in Germany with their explanation of the issues that have been discussed here about this lens, titled: "Information About Special Features for Dealers and Users." Or click on the Luminous Landscape link in post #1 for an abbreviated version of this statement in their "update" at the end of the article.

I agree with everything you said about not understanding why they chose f/2.8 & posted the same feelings on that thread. I won't repeat them here.

At least it is useful to know that the adjustment is available. I would guess that anyone buying the lens can request the adjustment in advance if they buy on-line from the Zeiss Shop on their website rather than from a dealer who already has the lens in stock. Ordered in this manner, there would be no need to send the lens back.

Cheers,
Huck
 
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I can't believe so many are ready to let Zeiss off the hook so easily. A lens that front focuses at f1.5 will only be a lens that backfocuses at f2.8 after the adjustment. The amount of shift seems to range from minimal to very notable based on sample. My two lenses showed the most shift in middle distances, and were actually quite usable at .9m.

I'll say it again...Zeiss needs to restate the MTF data on their site. A wide aperture lens that can't focus accurately or predictably at full aperture is pointless. I'm sorry, but I'm frankly amazed how many people are such fervant apologists for Zeiss on such a basic issue. If Nikon did this they would be hung from the lamp posts.
 
I have a follow up question here. So, from what I understand, it's the sonnar design that causes this issue, right? WIll other lenses do that? I have a sonnar type Medium format lens. So, if I focus it wide open on a tripod and than not change anything other than f stop - will it act the same? It's a SLR Medium format camera.
 
The Sonnar design in medium format shouldn't be as much of a problem if the lens is f/2.8 or smaller and minimum focus is held to about 1 meter or so. I think it's only high speed coupled with close focus that invites trouble in the Sonnar design. The Sonnar design apparently doesn't do well if focus is too close as explained here: http://www.nikon.co.jp/main/eng/portfolio/about/history/nikkor/nwords-e.htm#sonnarty
It was for this reason that Nikon went from a Sonnar design to a Xenotar (modified Gauss) design on their famous 105/2.5 thereby improving close up performance allowing minimum focus to be slightly reduced from 1.2 m to 1 m.
 
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Dan States said:
I can't believe so many are ready to let Zeiss off the hook so easily.
I'm sorry, but I'm frankly amazed how many people are such fervant apologists for Zeiss on such a basic issue.
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In my last post I was in no way defending Zeiss over this issue. I personally feel deceived by Zeiss. I bought a f1.5 lens to be able to use it wide open, there was certainly no data out when I purchased the lens that would suggest using it wide open would be a problem.
My only defence of Zeiss was that since this is the way the lens was designed we should not malign the QC process.
Cheers,
Nick
 
I think Zeiss could have been a bit more honest up front in it's description and mentioned somehow in passing a comparison to performance differences/advantages with the Planar. That way, one's expectations are reasonable rather than vague nostalgic comparisons to the "classic" Sonnar. I personally was a little wary of it's close up performance since they conservatively limited close focus to 0.9 m but I wrongly thought it was only in respect to flat field, not significant softness from SA induced focus shift. I was also taken aback by the surprisingly low contrast performance on the published MTF graph at f/1.5 AND f/4. Just speculating, but maybe the SA is the culprit here. This however, may be a big selling point for those looking for an orthodox design with less harsh contrast found in lenses from many decades ago (e.g. first Summicron) but free of internal reflection and flare with those early designs.
 
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Thanks for your link above, Alan. Here's another chapter from that same Nikon site, which discusses the Sonnar design as applied to the 85 mm focal length, but the imaging characteristics are the same as with the 50 mm focal length, as is stated in the article. I'll highlight the following comments:

. . . the closer the lens is focused to the closest focus distance, the softer the image becomes . . . It can be said that the characteristic of this seeming shortcoming is well suited for portraiture or photography of a fixed still subject and the lens delivers an exquisite imaging characteristic.

. . . stopping down the lens to f/5.6~f/8, the lens renders a sharp and high contrast image characteristic peculiar to the Sonnar type. At a maximum aperture or its vicinity, portraiture is suitable and landscape photography is also suited on stopping down; in this way, the lens is of use just like "killing two birds with one stone."
 
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awilder said:
I think Zeiss could have been a bit more honest up front in it's description and mentioned somehow in passing a comparison to performance differences/advantages with the Planar. That way, one's expectations are reasonable rather than vague nostalgic comparisons to the "classic" Sonnar.
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Something like this?

www.rrisonmind.net/entry/The-answer-from-Carl-Zeiss-from-Germany
 
Bottom line, Huck highlights the correct point on the dual use of this lens as does Zeiss in their clarification to dealers on imaging of the lens and it's Softar effect wide open for portraiture. Too bad Zeiss didn't play that up in the initial description, it might have given a more realistic expectation for people deciding about it's purchase.
With all the fixation on image softness wide open at close range, how does the lens perform wide open at infinity and mid-range, say 3 meters? If reasonably sharp, I've got no issue with the lens. If however, softness wide open is substantial as to be reseved as a last resort rather than for useful low light work or subject isolation, then Houston, we've got a problem.
 
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awilder said:
Bottom line, Huck highlights the correct point on the dual use of this lens as does Zeiss in their clarification to dealers on imaging of the lens and it's Softar effect wide open for portaiture. Too bad Zeiss didn't play that up in the initial description, it might have given a more realistic expectation for people deciding about it's purchase.
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Exactly.

With all the fixation on image softness wide open at close range, how does the lens perform wide open at infinity and mid-range, say 3 meters? If reasonably sharp, I've got no issue with the lens. If however, softness wide open is substantial as to be reseved as a last resort rather than for useful low light work or subject isolation, then Houston, we've got a problem.
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Write-ups about the old Sonnars & pictures that accompanied them always seemd to present the Sonnar as a portrait lens, which is what the Nikon links seem to say as well - adding that it has other benefits stopped down where it is very sharp. In the days before advancements in mid-length telephoto lenses as portrait lenses, I'm sure that the softening effects & reduced depth of field at f/1.5 were very attractive. Even after the development of longer portrait lenses at fast speeds, its compact size makes it very attractive as a lens to carry around which can be used for the combination of its special effects wide open & its all-purpose uses at slower speeds.

In general, it does not strike me as an all-purpose low light/available light lens unless you like the look at f/1.5 - which some obvioulsy do. Certainly not a competitor to the Summilux ASPH. It seems to me to be a lens more for special applications, which is still a great thing to have & still a lens that might be quite frequently used by some, depending on the kind of shooting you most often do. Right tool for the right job.
 
A work-around the softness issue for sharper portraiture is to utilize an old trick Leica use to suggest for a more pleasing pespective by framing the subject using the 90 mm framelines when shooting with a 50. This way perspective is improved WRT facial features and the longer subject distance mitigates some of the close focus aberrations although it might be a wash with the extra enlargement or cropping needed.
 
awilder said:
A work-around the softness issue for sharper portraiture is to utilize an old trick Leica use to suggest for a more pleasing pespective by framing the subject using the 90 mm framelines when shooting with a 50. This way perspective is improved WRT facial features and the longer subject distance mitigates some of the close focus aberrations although it might be a wash with the extra enlargement or cropping needed.
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That's a cool idea..! Even for non-close-focus things. I'm not good with a 50, this may certainly help :D
 
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