Jump to content
Sign in to follow this  
guy

35mm Summilux - do I dare?

Recommended Posts

Advertisement (gone after registration)

BTW, some of the current Zeiss designs show very mild focus shift as well. One example is the 35/2.0 Biogon. That said, the degree to which many lenses shift focus can tend to have minimal impact on most photography, especially hand-held work.

 

Cheers,

 

Sean

Share this post


Link to post
Share on other sites
BTW, some of the current Zeiss designs show very mild focus shift as well. One example is the 35/2.0 Biogon. That said, the degree to which many lenses shift focus can tend to have minimal impact on most photography, especially hand-held work.

 

Cheers,

 

Sean

 

Sean,

 

Did you by any chance test more than one CZ 35B? If so was there any sample variation that seems to be present in some Leica lenses? I am guessing that due to both the robust design, traditional very tight CZ QC and Cosina manufacturing practices, there may be minimal sample variation, hence the absence of complaints on CZ lenses. They do what they say on the tin.

 

Wilson

Share this post


Link to post
Share on other sites

The Leica lenses which have the most problems are faster than most Zeiss lenses, ie. the 35 Lux Asph and 50 Lux Asph. The fastest Zeiss lens, and the only one faster than f/2, is the 50/1.5, which is a soft-focus lens, with deliberately uncorrected spherical abberation. It seems that Zeiss is avoiding the whole issue, perhaps deliberately.

Share this post


Link to post
Share on other sites
The Leica lenses which have the most problems are faster than most Zeiss lenses, ie. the 35 Lux Asph and 50 Lux Asph. The fastest Zeiss lens, and the only one faster than f/2, is the 50/1.5, which is a soft-focus lens, with deliberately uncorrected spherical abberation. It seems that Zeiss is avoiding the whole issue, perhaps deliberately.

 

Carsten,

 

I suspect you might be right about deliberate CZ design decisions. However I was not just thinking of aperture shift. Their are a number of complaints about basic back and front focus errors on every new lens from the 21 Elmarit to the 75 Summicron. I think I am right in saying I have not yet seen a complaint on a CZ lens of manufacturing/adjusting errors. For someone like Sean who sees often more than one sample, I was interested to see if my surmise was borne out in practice and there really is no sample variation in the CZ lenses. If this is the case, it is a big plus point for them. Their best may not be as good as the Leica best but their standard, you get it every time lens, may be as good as the Leica average, if you see what I am getting at.

 

Wilson

Share this post


Link to post
Share on other sites

There have been some problems with Zeiss lenses also, but much more rarely than Leica, you are right there. However, if you remove the fast Leica lenses, and start at f/2 or f/2.8, then the comparison is less lopsided. The focusing problems have overwhelmingly been with the 35 Lux Asph, 50 Lux Asph, and Noctilux, with a few others also being represented, but much less frequently. I am not sure if Zeiss is doing better overall. It could be. I don't think the difference is that great though.

Share this post


Link to post
Share on other sites

Wilson, you're probably tired of my input on the topic, but here goes:

 

Zeiss designs are less sophisticated than Leica designs. EP mentioned that in his Zeiss reviews and now mentions it again in the article on the Summarits. As such, they can stand more slop in assembly than the Leica counterparts.

 

Leica lenses pull all the stops--special glasses, aspheric elements and very stressed designs. One minor error in assembly has a major effect.

 

Example from Puts: If you design two comparable lenses, but one uses six elements and the other uses only four to reach the same level of correction, then in the 4-element lens, each element has a bigger job. If something is just a little off in the 6-element lens, there are five other elements to cover the slop; but with only four elements, each one must carry its full load.

 

The focus problems (my belief, I don't think Carsten buys this to the degree I do) have come in final assembly. The optics work as designed, but a slight error in setting the lens in its mount (not getting the shim right to get proper lens-to-sensor distance) has made part of the design (intentional focus shift) visible and problematic.

 

[i make that argument without having seen the new LFI, which will likely lead to a more refined argument when it arrives.]

 

As Carsten said, the problematic designs have for the most part been Leica's highest-speed and most state-of-the-art lenses, where a very slight error in assembly will have noticeable detrimental effect. So far, the only Zeiss lens that pulls out all the stops is the 15/2.8. In general, their lenses are good, conservative designs--similar to what Leica is now attempting in the new Summarits.

 

In other words, it's _because_ of the extreme sophistication of the Leica designs that some samples misbehave. Similarly, because the Zeiss designs are simpler and more tolerant (and slower), they tend to give fewer 'problems.'

 

Remember, in the 50/1.5 Sonnar-C, Zeiss even advises users that the lens suffers from severe focus shift with changes in aperture by design. So now, you can't complain of focus shift since the manufacturer has said it's supposed to work that way.

 

--HC

Share this post


Link to post
Share on other sites

Advertisement (gone after registration)

Howard,

 

You are saying absolutely nothing I disagree with. I think the point I was trying to make was that Leica may have designed lenses that are beyond the abilities of a regular production line/human beings to make to the standard which will consistently produce the stunning results they should be capapble of. Zeiss have, it would seem, analysed the production capabilities of their facility and designed lenses to suit.

 

I don't know if you are old enough to remember when Angenieux zoom lenses first came out for SLR's in the early 1960's. Angenieux had been making them successfully and individually by hand for 35mm movie cameras (BNC etc - the King and I was filmed with them on the suggestion of Yul Brynner, a keen Leica man). However when they tried to transfer this technology and scale up production for 35mm still cameras, the results were pretty disappointing. My uncle had one, which he was very proud of, on his Voigtlander SLR. I recall my father, somewhat cruelly, being very disparaging over the results and comparing them very unfavourably with the results from his Contarex/Planar 55/1.4. They were eye-wateringly expensive. Some similarities to the production scenario for the Luxes, both Summi and Nocti?

 

Wilson

Share this post


Link to post
Share on other sites

Wilson--Thanks for the response. I usually think we're pretty much on the same page, so I may tend to read more into your comments when I think I see a difference between us.

 

The Puts article on the Summarits certainly repeats what you say. And I like his comment that Leica were never great innovators, but were excellent improvers. And with the Summarits, he feels, Leica has begun to accept the Zeiss design philosophy--more power to them!

 

Ah, yes, Angenieux! I didn't know the Yul Brynner story (or that he was a Leica enthusiast), but I remember the company's attempt to enter the 35mm market. At one time Leica also offered an Angenieux 45-90 for the R, as I'm sure you know, and at a price high even for Leica at the time.

 

The parallel to the Summiluxes and Noctiluxes is well taken.

 

And today it seems that in some cases, zooms outperform primes. And Leica is introducing a new line of less expeensive lenses! Things do change, as Heraclitus and the Buddha both told us!

 

--HC

Share this post


Link to post
Share on other sites
Sean,

 

Did you by any chance test more than one CZ 35B? If so was there any sample variation that seems to be present in some Leica lenses? I am guessing that due to both the robust design, traditional very tight CZ QC and Cosina manufacturing practices, there may be minimal sample variation, hence the absence of complaints on CZ lenses. They do what they say on the tin.

 

Wilson

 

Hi Wilson,

 

I've worked with three or four samples of that lens but only done focus shift testing on one sample.

 

Cheers,

 

Sean

Share this post


Link to post
Share on other sites
The Leica lenses which have the most problems are faster than most Zeiss lenses, ie. the 35 Lux Asph and 50 Lux Asph. The fastest Zeiss lens, and the only one faster than f/2, is the 50/1.5, which is a soft-focus lens, with deliberately uncorrected spherical abberation. It seems that Zeiss is avoiding the whole issue, perhaps deliberately.

 

And yet...the following all focus correctly and show no noticeable focus shift:

 

50/1.5 Nokton

35/1.2 Nokton

35/1.7 Ultron

 

So its possible. <G>

 

Cheers,

 

Sean

Share this post


Link to post
Share on other sites
Carsten,

 

I suspect you might be right about deliberate CZ design decisions. However I was not just thinking of aperture shift. Their are a number of complaints about basic back and front focus errors on every new lens from the 21 Elmarit to the 75 Summicron. I think I am right in saying I have not yet seen a complaint on a CZ lens of manufacturing/adjusting errors. For someone like Sean who sees often more than one sample, I was interested to see if my surmise was borne out in practice and there really is no sample variation in the CZ lenses. If this is the case, it is a big plus point for them. Their best may not be as good as the Leica best but their standard, you get it every time lens, may be as good as the Leica average, if you see what I am getting at.

 

Wilson

 

Hi Wilson,

 

The CV lenses can have sample variation problems for sure but I don't see those problems as often as I'd expect, given how inexpensive the lenses are. Also, a bad copy of a CV lens (when I see them) might be de-centered, soft in the corners, etc. but I don't yet recall testing a CV lens that didn't focus correctly on the M8. I'm sure its possible, I just haven't encountered that yet.

 

As far as Zeiss goes...the preproduction 85/2 I just tested was way off focus on the M8 *but* its not a full production lens and so it may not be indicative of a general problem. The Cosina Zeiss lenses (if we might call them that) have all focused correctly (to the best of my memory).

 

Cheers,

 

Sean

Share this post


Link to post
Share on other sites
Sean,

 

Did you by any chance test more than one CZ 35B? If so was there any sample variation that seems to be present in some Leica lenses? I am guessing that due to both the robust design, traditional very tight CZ QC and Cosina manufacturing practices, there may be minimal sample variation, hence the absence of complaints on CZ lenses. They do what they say on the tin.

 

Wilson

 

BTW, before we get confused...

 

CZ is Contax Zeiss

CV is Cosina Voigtlander

 

Some people also write VC but that's incorrect because the parent company is Cosina and they simply license the Voigtlander name.

 

I'm fairly sure you meant CV.

 

Cheers,

 

Sean

Share this post


Link to post
Share on other sites
BTW, before we get confused...

 

CZ is Contax Zeiss

CV is Cosina Voigtlander

 

Some people also write VC but that's incorrect because the parent company is Cosina and they simply license the Voigtlander name.

 

I'm fairly sure you meant CV.

 

Cheers,

 

Sean

 

Sean,

 

I actually did mean CZ = Carl Zeiss but I was talking about Cosina manufacturing practices because, as I am sure you know, they make all the CZ lenses other than the 85/2 and the 15/2.8. On the assumption that CZ have carried on the same practices as they had at Kyocera, the QC inspection team, although Japanese nationals, are Zeiss employees. I believe that was a source of considerable friction at Kyocera because of the high rejection rate of the N mount lenses. I agree with one of your comments above, the CV 35/1.2 is a tour de force at the price. Mine is spot on with the tests I did both on wine bottles and the Nikon chart. It is beautifully made and I love the sun hood. I wish that Leica had done something similar with the Noctilux rather than that pathetic wobbly plastic thing. I don't know how CV do it for the price.

 

Wilson

Share this post


Link to post
Share on other sites
Some people also write VC but that's incorrect because the parent company is Cosina and they simply license the Voigtlander name.

 

Perhaps they write VC for the heroism of Cosina in releasing those original 15mm and 25mm lenses all those years ago.

Share this post


Link to post
Share on other sites
And yet...the following all focus correctly and show no noticeable focus shift:

 

50/1.5 Nokton

35/1.2 Nokton

35/1.7 Ultron

 

So its possible. <G>

 

Cheers,

 

Sean

 

So do my 50 Lux Asph, 35 Lux Asph, 75 Lux and the Noctilux I tried! We do need more samples to test variation. Besides, at the least the first two of those are closer to the previous generation of Leica lenses in design and performance.

Share this post


Link to post
Share on other sites
So do my 50 Lux Asph, 35 Lux Asph, 75 Lux and the Noctilux I tried! We do need more samples to test variation. Besides, at the least the first two of those are closer to the previous generation of Leica lenses in design and performance.

 

Carsten,

 

It may be that due to the differences in pricing between Leica, CZ and CV lenses, people's expectations are different. In other words if you buy a relatively cheap CV lens and it is not perfect, you are prepared to live with it. However if you buy a €5,000 Noctilux and it is not perfect, you are horrified and shout from the roof tops.

 

Wilson

Share this post


Link to post
Share on other sites

wlaidlaw wrote: I think I am right in saying I have not yet seen a complaint on a CZ lens of manufacturing/adjusting errors.

 

Well, just for the record, I recently bought a 25 mm ZM lens and it front focuses visibly wide open. Stopping down introduces some focus shift that reduces the ff. The rest I've corrected by carefully filing off the cam

So I'm afraid the Zeiss lenses have problems too.

Share this post


Link to post
Share on other sites
wlaidlaw wrote: I think I am right in saying I have not yet seen a complaint on a CZ lens of manufacturing/adjusting errors.

 

Well, just for the record, I recently bought a 25 mm ZM lens and it front focuses visibly wide open. Stopping down introduces some focus shift that reduces the ff. The rest I've corrected by carefully filing off the cam

So I'm afraid the Zeiss lenses have problems too.

 

Arne,

 

As a matter of interest, why did you attack the lens yourself rather than getting it corrected under guarantee. Was it because like me, you had bought from HK or Japan and it was impractical to return it. I would also say that filing the cam is a rather irreversible action. If the lens follows previous CZ practice, the optical cell is adjustable relative to the focus barrel and I would assume also to the focus ramp/cam. CZ does not use shims to adjust the ZM mounts or there were certainly none on the two I have taken apart. However, any adjustment would have to be done on a jig, while the lens is in an optical bench, so not exactly home mechanics.

 

I would have been surprised if there were no reported problems on CZ lenses - that would be just too much to hope for but yours is certainly the first post of a focus problem I have seen.

 

Wilson

Share this post


Link to post
Share on other sites

Wilson,

You're right, it was bought (not by me) from a shop in Japan. As for the adjustment, I was curious to see if I could do it.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue., Read more about our Privacy Policy