Sample Variation in Lenses

[rob_w]

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Ming Thein has written a thought-provoking and worrying piece on this topic over at Quality control, sample variation and what it means for photographers – Ming Thein | Photographer

 

I was surprised to see his experience with Leica lenses given as the chosen example. In the subsequent discussion a number of correspondents came forward with examples of Leica quality variation.

 

In my own experience, all Leica lenses I have used have performed to a high standard. Being hand-made I expect they receive sufficient individual attention to produce a high quality product. I have often read complaints of sample variation between lenses from other manufacturers, but do not recall seeing the same complaint about Leica sample variation, at least not on this forum.

 

Is my perception right: what is the experience of forum members ... does Ming Thein make a fair point ... should his target be other manufacturers, even more so ... is 'guaranteed quality' the core of Leica's brand proposition ... if so, how do they maintain it ... if Ming Thein is right, how do we ensure we are buying the quality we expect?

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[Jeff S]

I actually read a number of complaints about Leica QC (camera and lens), and on different individual experiences, on the forum, but to your more general question, lens sample variation is a fact of life, even with very expensive lenses.

 

You might want to read this lensrentals article, particularly the section titled 'The Single Copy Phenomenon'. Following is an excerpt…

 

"If you’ve ever read anything I wrote, you probably already know this. If not, here’s an absolute reality you need to digest. Every copy of lens X is just a little bit different from every other copy. Every copy of camera Z is just a little bit different from every other copy. There are manufacturing tolerances for such complex devices that are unavoidable at any price.

 

If you can’t accept it, you definitely need to stop pixel peeping. You’ll go insane. If you want to say, “For $2,000 every lens should be perfect” then you are very naive. We have $50,000 cinema zooms and they are all slightly different, too. In fact, at the very highest levels, technicians will hand calibrate each $50,000 lens to the $100,000 camera because there is still variation."

 

Roger at lensrentals rents Leica lenses, so these are ones he has tested and is quite familiar with. The brand isn't exempt from reality. Now, whether this affects image quality as a practical matter is up to the user.

 

Unless you've done, or had someone else do, tests using your own lens, then you may not know exactly how it performs relative to others. But, variation in lens tests is another rabbit hole, as this article describes.

 

So, as long as you're happy with your results, that's what matters.

 

Jeff

[Jeff S]

And here is another article from Roger on lens variation, even more to the point.

 

Jeff

[DMJ]

In my experience Leica are good at sorting out problems. They are a bit slow but the result is ok.

[Jeff S]

They are a bit slow but the result is ok.

 

Not always, for me , using Leica NJ. And others have discussed issues with Solms on occasion, having to send product in multiple times for various problems, including sample variation and dissatisfaction with the 'flagship' 50 APO Summicron-M (see thread on central veiling flare, for instance).

 

Jeff

[rob_w]

I found the article pretty troubling but seem to be alone with that concern.

 

Of course I know there is sample variation in all manufactured goods including camera lenses. But Ming Thein is not talking about product variation within acceptable final tolerances. He is talking about needing to replace several Leica lenses which were not good enough.

 

Maybe I should have titled this thread: "Sample variation -- are Leica the worst?"

[jankap]

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Thanks for starting the thread.

Some remarks in the article are unclear.

1. There is no good or bad. The problem is not digital, it is analog. Perhaps it follows a Gauss

distribution.

2. The comparison Nikon with Sony is apples and oranges.

The Nikon focusses via a mirror. The Sony focusses with the sensor.

The Nikon has the same problem as a rangefinder camera, namely separate ways of focussing and

picture taking .

 

I did not read further.

Perhaps the problems with Leica are the known (see forum) rangefinder adjustment problems.

 

I seldom take photos of documents (ima test charts), to be honest I never do. So how do I know my lens is worse than the aimed quality?

 

My dealer will not have 8 samples of for instance a SEM 21. And I don´t think, he will lend me them for a weekend. And if yes what do I do? Taking photos of brick walls with 8 lenses? My methods will be inferior in comparison with those of QC of the manufacturer. So what would I measure then?

 

A proposal: Lens rentals could offer a service to imatest lenses for private photographers. In that case I became a diagram of my lens used with an adjusted camera of lens rentals. For a certain fee + shipping + handling.

Jan

[Rick in CO]

I found the article pretty troubling but seem to be alone with that concern.

 

Of course I know there is sample variation in all manufactured goods including camera lenses. But Ming Thein is not talking about product variation within acceptable final tolerances. He is talking about needing to replace several Leica lenses which were not good enough.

 

Maybe I should have titled this thread: "Sample variation -- are Leica the worst?"

 

This is why one should immediately take some test pictures with any lens purchased - second hand or brand new. I don't think you can brand "Leica the worst", as all manufacturers have the same issue. Leica is probably better than most (an opinion). As probably is Zeiss. Linhof actually tested the lenses they sold with their cameras before they inscribed their logo on them. The return rates I don't exactly remember, (the info is out there somewhere in the etherea) but was fairly significant for Rodenstock and Schneider, minimal for Zeiss. I have had a mediocre 50 Summicron, and a so-so 135 Elmarit which, after fine tuning adjustment is very very good. It may be that calibration to your camera is the key. Linhof and Rollei hand tuned the lenses to their cameras. Leica offers the same service, if desired. Both Leica and Zeiss forums have threads on the use of lenses designed for film cameras being "variable" on flat (planar?) digital sensors. Along that line of thought Ming Thein agrees with Roger Cicala on the use of adapted lenses - introducing just more potential for variability. The Leica user should also read Erwin Put's articles on the subject of sample variation. Basically, in the real world, one should never buy any lens without a return promise. One never knows the life of that used lens has seen but a new lens is expected to be good. How does one know if a lens is good? Take a lot of pictures until you're satisfied. Or, look up Roger Cicala's Lens Rentals articles on testing lenses and knock yourself out. There is a lot of opinion out there on which testing paradigm is more relevant to "real world" results, one must simply satisfy themselves.

[pico]

Linhof actually tested the lenses they sold with their cameras before they inscribed their logo on them.

 

What evidence have you to support that claim?

.

[hanexp]

What evidence have you to support that claim?

.

 

It's been many years but the memory I have is that the regional Sinar rep told me that the Rodenstock and Schneider lenses stamped "Sinar" were tested by Sinar. Too long ago but I never would have wanted to return any of the three Sinar stamped lenses I owned for image quality issues.

[semi-ambivalent]

I think something that might come out of this is that, with increasing pixel density in digital cameras, the problem becomes, not the resolution of a particular optical formula, but the mechanical assembly of that formula into a physical lens to be sold for $X. At some point even the robots will not be able to maintain consistent specs. Leica has the luxury of charging thousands of dollars for a lens, Zeiss too, it appears. The others are not so lucky and the stakes are getting higher. At what point does the digital world stop selling resolution to get you to buy the next rev? What do you mount on your 50MP FF camera? A $20k cinema lens? Or do you finally say the hell with it, and go back to taking pictures rather than reading spec sheets? Digital pixel density is not going to stop at FF 36MP.

 

I shoot film so I don't have a dog in this fight, but there's a reckoning coming for the market, and it's going to be very interesting to watch it play out.

 

thanks,

s-a

[jankap]

What evidence have you to support that claim?

.

 

It would be stupid to sell products of somebody else under your name without any check.

If that comes out, the OEM will sell his crap to you.

Jan

[pgk]

OK so here's my take on this. Sample variation is inevitable. Its just something that we have to accept. Sure you can tighten tolerances - but this increases cost (I remember discussing this topic with a lens designer friend who said that he suspected that we would hit a MPixel point which would require tighter tolerance in lens manufacture and this would increase costs substantially).

 

However. Leica M lenses are mechanical and hand-built and can be adjusted as evidenced by many threads on this forum. Having taken apart (wrecked) lenses from several manufacturers (I retain useful parts such as small screws and mounts) I can honestly say that some (perhaps many) modern lenses seem to rely on a lot of molded plastic components to reduce their production cost and I cannot see how these lenses can be easily adjusted - firstly because I imagine that the production process is designed to place the lenses performance within a predicted tolerance and I can't see anything which ;looks easily adjustable, and secondly, because it would almost certainly not be economic to use a technician's time to do so. So whilst there will be variation in all lens production, at least with a mechanical, hand-built lens this can be potentially adjusted to optimise performance and the lens improved.

 

Given that I am using 50 year old lenses on my M9 I see little reason to think that sample variation in M lenses is truly a huge problem and even these can be adjusted (most anyway) to perform better if needed, and many can be coded to boot;).

[NJH]

I just accept that I will have to buy and sell a lot of lenses to get a set I really like. My copy of the CV 90 APO Lanthar is a case in point, it cost me very little but seems to be a really superb copy. On the other hand all 3 CV lenses I have had have been really good, the other 2 being the 21 and 25 Skopars.

 

I wouldn't waste any time or thought on doing studio type comparison test shots, like dpreview. This will drive you crazy. At one time I think I had 5 of the m4/3 lens range, two of those the Panasonic zooms including the oft mentioned 100-300 which I felt was complete junk. I set up a comparison test indoors to test my favourite lens in that format, the Oly 45 against the Panasonic 14 and 20 pancakes. I didn't like either of those Pansonic lenses much, very harsh rendering. Well you can guess what happened the Oly came last on both centre and corner resolution, the 14 and 20 almost identical. The difference was sizeable. I never published my test notes and images on the m4/3 forums because i was so disillusioned by the results, I really loved the images coming out of that little 45 but it was plain soft in direct controlled comparison.

 

If you like the images you are getting out of a lens and it works for you in the final production form of your photographs then you keep that lens, if it doesn't you move it on and try something else and that is all there is to it in my opinion.

[Rick in CO]

What evidence have you to support that claim?

.

 

Linhof catalogs stress this information, as have other independent sources throughout the years. The lenses and shutters that pass testing get inscribed with the Linhof logo. If you visit the Linhof factory in Munchen, as I have, and they are not too busy, you might get a tour of their facilities including the testing lab.

[Jeff S]

What do you mount on your 50MP FF camera? A $20k cinema lens?

 

Post # 2…..not even a $50,000 lens on a $100,000 camera evades the lens variation issue.

 

Jeff

[semi-ambivalent]

Post # 2…..not even a $50,000 lens on a $100,000 camera evades the lens variation issue.

 

Jeff

 

Exactly, but it does buy one some time. So $ buy a solution but only for so long before the mass-market peasants revolt, and while many might spring for an APO Summicron I doubt enough will to keep production cash positive. Mass-production works only because there is mass consumption. Once a technology level, like phones, does everything needed by most of its users the equation begins to fail. Then something else must be included to keep or re-start the upgrade cycle. It won't be $15k Summiluxes. (Really, not picking on Leica here. My F3s used to be $2500. Now they're what, $125?)

 

thanks,

s-a

[250swb]

Linhof catalogs stress this information, as have other independent sources throughout the years. The lenses and shutters that pass testing get inscribed with the Linhof logo. .

 

It is true that Linhof test lenses, but a 'good' Linhof branded lens is no better or worse than the ones supplied by the OEM, it is just a marketing ploy to justify an increase in price. The lenses have already gone through the quality control of the OEM, so it is simply double checking the performance. Of course when it comes to Leica it is the customer who does the second test, but in a lot of years buying Leica lenses I have only had one that was out of adjustment so I'm always a bit sceptical of horror stories coming to light along with the inevitable extrapolation of ill founded conclusions concocted from just a few figures.

 

Steve

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Hallo,

Look here: Leica M

[pico]

It is true that Linhof test lenses, but a 'good' Linhof branded lens is no better or worse than the ones supplied by the OEM, it is just a marketing ploy to justify an increase in price.

 

 

How about an authoritative source?

 

 

 

 

Sent from my Etcha-sketch.

[250swb]

How about an authoritative source?

 

 

 

 

Sent from my Etcha-sketch.

 

About what? Linhof testing lenses, or OEM being as good? I'm not a mind reader. It would help if you have a 'theory' you interjected with it instead of asking everybody else to prove your idea for you.

 

But to try and short circuit your general scepticism I go on my own experience with large format lenses over thirty years and those from many other users of large format cameras. An OEM Schneider is no better or worse than the Linhof branded version, it is the same lens, otherwise how could Schneider get away with marketing an inferior product that is identical to a Linhof badged product? And then there is the experience of using them, in which, there is no difference, just the smoke and mirrors of marketing name plates. Prove me wrong.

 

Steve