Hey early birds, here is a can of worms. Are the M mount lens that are interchangeable between Leica, Konica Hexar, Voigtlander and Minolta the CL and CLE in fact optically compatible? Do we risk image degradation if we use Hexars on Leica M's, Leicas on the Hexar RF and anything but Minolta lenses on the CL and CLE? Should Voigtlander lens only be used on Voigtlander cameras?

In his review of the Hexar 35/2 Erwin Puts tells us: "The inevitable question of course is how this Hexar lens compares to the last non aspherical Summicron. In my view the Hexanon is the better lens overall." Having opened up a big can of worms with that, he goes on to open up even a bigger can:

"But you cannot use the Hexanon lens on a Leica body: a collimator check showed that the Hexanon lens has a focus plane that differs from the Leica lens by 0.09mm. Is that important?

"The discussion on the Lug about the Hexar body/Leica lens compatibility dismissed small differences in the area of less that half a mm as irrelevant, because some uses could not detect any difference when comparing different lens/body combinations.

"The truth is this: I did a test on the bench and focused carefully on maximum image quality. Then I used a micrometer to defocus by 0.03mm (which is quite small). In the image the loss of contrast was very evident, but resolution at least at the lower frequencies (around 40 lp/mm) did not suffer. What did suffer was the edge sharpness.

"If you were to do your own testing and looking at the negatives with an 8-times magnifier, you would not see any drop in resolution (beyond the detection capability of the eye at that magnification). But at a larger magnification you begin to see it quite clearly."

Regarding "the system view" he concludes:

"I am a strong believer that engineers design tools with a specific background and integrate components that do match as smoothly as possible to the character of the tool.

"No one would buy a Mercedes Benz and will retrofit it with a BMW engine, even if it would fit technically. The characters are too different. So I am proposing that you should use Konica lenses on a Konica body, Leica lenses on a Leica body and Voigtlander lenses on a Voigtlander body.

"My argument is not just brand loyalty, but the view that bodies and lenses are designed with a certain set of specifications and engineering parameters. Mixing them may be possible but do you get the best of both worlds?"

This has been kicked around before. Can we have a definitive discussion on this? Stephen Gandy, Tom Abrahamsson, Erwin Puts and any other gurus out there--please help us out!

-- Alex Shishin (shishin@suma.kobe-wu.ac.jp), January 22, 2002

Answers

I am no Guru but it makes no sense to me to use third party lenses on Leica cameras if you have any choice in the matter. Regardless of arguments about optical quality, the fact is that Leica goes to considerable trouble to ensure compatibility between its lenses and Leica camera bodies. A third party manufacturer does not. If the combination works, then fine, you're lucky, but there's no guarantee of this and you have no recourse if it doesn't.

-- Ray Moth (ray_moth@yahoo.com), January 22, 2002.

..but resolution at least at the lower frequencies (around 40 lp/mm) did not suffer

This means that all of us who shoot handheld w. 400 iso film, will not notice.
The definitive answer is that: Puts has established that there is a 0.09mm difference and that it does make a difference, AND most users claim that they work perfectly well together in practical use.
You just have to choose your own religion.

-- Niels H. S. Nielsen (nhsn@ruc.dk), January 22, 2002.

defocusing by 0.03mm? with a micrometer?

as most m-users shoot handheld, one should use a micrometer to measure how much we are rocking for- and backwards just by breathing and heart pounding. i'd guess it is more than that.

i'd presume most RF users would buy leica lenses, but the cost is a major concern of course.

-- stefan randlkofer (geesbert@yahoo.com), January 22, 2002.

Look at what Stephen Gandy wrote yesterday (21/01/02) about Hexar RF on the way out ?

-- Lucien (Lucien_vd@yahoo.fr), January 22, 2002.

There's a problem between the test and the way real life works. Erwin notes a loss in resolution on a flat subject with a focus error, but a real photographer would simply notice that while the image is still sharp, he didn't put the focus quite where he wanted to. Since in spite of efforts to the contrary, there's bound to be a little focus error in most pictures under casual circumstances, then the lens owner is left uncertain if the lens or himself is the problem. I think that's why a lot of people who claim the Hexar issue is a non- issue: except under lab circumstances, most people just aren't careful and critical enough to make an informed judgement as to whether the Hexar/Leica pair is actually working as it should, since the results come out about as nearly in focus as their usual stuff.

-- Michael Darnton (mdarnton@hotmail.com), January 22, 2002.

The back focus incompatibility has been thrashed out several times on the Leica Users Group. The back focus of a Leica is 27.95mm from bayonet surface to film pressure plate. The tolerance is +/- 0.02mm. The back focus with film in the camera is 27.8mm (+/- 0.02mm). For the Konica the back focus from bayonet mount to film pressure plate is 28mm (+/- 0.03mm). The source for the Konica numbers is the camera repair manual, and for the Leica numbers a repair instruction note from Solms. Confusion has been caused by comparing the back focus of the Leica with film in it (the 28.7mm number is in many books as the back focus number) with the Konica without film in it. Most Konica users mix and match Leica lenses without a problem but a few report focussing problems. It would be prudent to try a Hexar body with a wide aperture Leica lens before buying - but for the most part users in real picture taking situations have no compatibility problems.

-- Howard Cummer (cummer@netvigator.com), January 22, 2002.

In line 5 I have written 28.7mm - that should be 27.8 - my numerical dyslexia kicked in! Sorry.

-- Howard Cummer (cummer@netvigator.com), January 22, 2002.

One Leica-User has a Hexar RF that he regularly uses his Noctilux on wide open. He has no problems with focus.

-- John Collier (jbcollier@powersurfr.com), January 22, 2002.

Changing topics slightly, I use a Leica Tri Elmar on my Hexar almost exclusively and a sweeter combination would be hard to imagine. Aperture preferred, auto winding and with three focal lengths at the twist of a wrist. The optic is very very good and I have absolutely no focusing problems at all - perhaps partially explained by the slow F4.0 aperture and perhaps that my combination of gear is within the range of compatibility.

-- Howard Cummer (cummer@netvigator.com), January 22, 2002.

"..but resolution at least at the lower frequencies (around 40 lp/mm) did not suffer"

But that's begging the question, isn't it? It just means that despite the lower resolution, if the subject details are coarse enough, the lens can still find them. Like saying "at lower resolution, the lens can resolve."

-- Bob Fleischman (RFXMAIL@prodigy.net), January 22, 2002.

I know this is not a novel point, but... Konica themselves has claimed the incompatibility exists. Many argue that this is because they were afraid of a patent infringement suit by Leica. However, we know this is not the case, as the M mount itself was used and would have been enough to generate said suit. Alternatively, Bessa has come out with an M mount on their T without complaint bu Leica. So, it appears Leica is not about to sue anybody. In fact, cross manufacture of M-compatible products can only help Leica in the long run. (Remember the Sony Beta vs VHS tape debacle?) If Konica was smart, it would re-calibrate their lenses and body to match that of Leica specifications in a new "L" series!

For the most part, I shoot with Leica M's because I like the glass -- and I think that is why most of us put up with the lack of technical sophistication in the M line. But, if you want to use another lens, by all means go ahead! It is unlikely you will see any resolution differences hand-held anyway. Hence, it is only the other less objective qualities of the Leica glass that will not be present in your images...

:) Cheers,

-- Jack Flesher (jbflesher@msn.com), January 22, 2002.

Alex,

I am a happy user of the Hexanon 2/50. A very fine lens which fits my M2 very well. In practical terms I did not notice an incompability until now - shooting slides and bw. Under my 10x loupe all negs / slides were accurately focused and sharp as far as hand held shots can be.
I do not use a Summicron because I just cannot afford one - they cost about 3 times as much in a similar (ex++) condition. In general I like to have manufacturers lenses on my camera, but then if I cannot afford them why should I use no lens at all ? My first 50 was a $30 russian sonnar copy which was working fine on my M2; I'd rather shoot with that combo than with my old Canonet. In my eyes it is mostly a mental trick that prohibits you from using 'foreign' lenses with your high quality Leica body, but then you weren't able to use the relabeled Zeiss-Hologon or the Schneider-Angulon as well ...
Even if some lenses are not qa'ed according to Leica spec's, I don't see the necessarity herein. As long as my results are superb and I cannot see the difference I have no need to have an original lens. Though this is a point everybody has to make out for oneself - that's why lots of people still don't use the cheap 40 c-summicrons and 90 c- elamrs on their M. In my eyes a personal taste.

Kai

-- Kai Blanke (kai.blanke@iname.com), January 22, 2002.

Alex,

Good grief!!!

I use Leica's with my Hexar. And I used Konica Hexanon lenses on my M6. (When I had it)

When my family and I view our slides we use a projector and screen, not a 10X loupe. And we have never noticed "the edges." Or run screaming from the rooms due to the poor quality from the mismatch of equipment.

And when I take these pictures I never use a bench, or micrometer for focusing. Nor do I often use a tripod, nor hold my breath, nor time my shot's between heart beats. Any my pets and kids seldom hold perfectly still, or hold their breaths, or pulses. And sometimes I use Agfa, Ilford, Fuji, Konica, and Kodak. And I've never used Leica film. (Not yet anyways)

But then, I'm a mixed race mud person. My gramma was from Norway, and all the rest were from other european countries like UK, Germany, et.al. And I married a gal from a similar genetic concoction. And our kids are thusly mixed up. My dog is a purebread Englishman (I think thats were golden retrievers were cooked up) And Kitty's geneology traces from Siam.

Should Japanese only use camera's from Japan? And those from Portugal, Canada, and Germany are to use Leicas? Or maybe we ought have Irwin take all our pictures for us? What about the poor Aussie's? As Randy Newman sings, "they got surfin' too..." What are the poor Aussies gonna do for a camera? ("Don't want to hurt no Kangaroo...) I worry so for Australia.

And I think you get the gist of how ridiculous I find this topic...

-- David Smith (dssmith3@rmci.net), January 22, 2002.

I agree with David and find this post obsurd too. So should those M users with 15mm Voigtlanders not use them cause its not Leica? My CL is made in Japan by Minolta and my 40mm Summicron Made by Leitz Wetzlar so should i not use these together? Funny no M was given 40mm framelines! Should I not use modern Voigtlander lenses on my Leica IIIF and stick with the fogged, non multicoated flare prone old leica lenses if i want the best images I can get? An M body takes better pictures with an alternate lens that you can afford than having no lens at all because you couldnt afford the Leica one. Its price, size, weight, focal length availability that lets you select what suits you best. No one brand offers everything.

-- Joel Matherson (joel_2000@hotmail.com), January 22, 2002.

you got it Alex!

-- r watson (al1231234@hotmail.com), January 22, 2002.

And if you are concerned about the compatibility of lenses, just ship them to me: I'd take each uncompatible M-mount or LSM-lens before you throw them away ;-)

To get more serious: If this is really a problem for you, you need to have each lens calibrated to your body or just use a fixed lens camera where problems like these don't occur. Even Leica lenses may not fit 100%, though their QC is not too bad.

-- Kai Blanke (kai.blanke@iname.com), January 22, 2002.

I use whatever lenses take my fancy on whatever body that is handy. My selection includes Russian copies of Zeiss glass,a 50/3,5 from a Shanghai 58,Voigtlander/Cosina glass, a Macro-Switar 50/1,9 with a Alpa to Leica screw-mount adapter, a Pentax 43/1,9, Leica glass from F1 Noctilux to M-mount 50/3,5 Elmar and this is the selection for "normal" focal lengths only! There is rarely a problem with back- focus and film-plane distances. A couple of the Russian lenses showed softening of edges and that could have been traced to this, but it could also have been sloppy assembly. I tried the Hexar RF but decided that it did nothing for me as a camera. The finder is too fuzzy although it is a nice 0,58 magnification. I used it with both a Noctilux and a 35/1,4 Aspheric and could not detect any focus problem that could be blamed on the camera. The two Bessa-T's that I have both focusses the F1 and the 1,4's in the correct plane, even the 90/2A-A will work on those bodies. When we are looking at tolerances of +/- 0,03 mm we need to check filmthickness and filmflatness too as this would influence the values. My approach is that I try the combination, if it works I keep it, if it doesn't get rid of it! I use the Nokton 50/1,5 on my M's because it is a better lens than either of the two Summilux 50/1,4's that I have. There is nothing wrong in using non-Leica glass on your M's. If it makes the pursuit of images more interesting, go for it! Tom A

-- Tom Abrahamsson (TTAbrahams@aol.com), January 22, 2002.

From the tests, I would conclude that sticking with same-brand lenses is the best choice for taking photos of resolution charts or making measurements on an optical bench.

When I've convinced myself that my ability to focus accurately (and I'm pretty damned accurate!) is so good and consistent that a < 0.1mm variation at the film plane will have a noticeable effect on my photos, maybe I'll feel that mixing and matching is unwise.

-- Mike Dixon (mike@mikedixonphotography.com), January 22, 2002.

I have yet to use a Konica lens on my Hexar; and like everyone else here I've been happy (or at least not unhappy) with what I've gotten when I think I have shot well. Like everyone here, I carry a mixed bag into the field--Leica, Voightland, Minolta, Canon RF, Nikon RF lens which I randomly match with my Hexar, Leica M's, Leica L's, Canon RF's, CLE's, CL, Bessa T and Bessa L. And like everyone else here, I've reached the practical conclusion that the world of the field is different from that of the bench. Somehow our lenses--with their aberations, their flares, their soft corners, their minute bubbles, and their minute mismatches--muddle through (as do we).

This brings up the question of the true value of bench tests. I'm not being a wise guy here. I think that Erwin Puts and others do extremely valuable work for us. But what does it all mean in the end?

For me, it is important to know the intrinsic limitations of materials that I use. It is not something that I am obsessed with; but it is I keep at the back of my mind. And it helps. I wouldn't do architectural shots with a zoom lens because I know many zooms have linear distortion that is above that of prime lenses. If I ever do put a Hexar 35/2 on my M-6 I'll make it a point of not shooting a flat surface where edge quality is important (say if I have to shoot a painting or something).

I agree with everyone, and (with all due respect) disagree with Erwin's last statement regarding strictly not mixing brands. I don't think it is quite like retrofitting a BMW engine into a Mercedes Benz.

This said, I have, thanks Erwin, been made more conscious of what I do with my equipment. My Leitz 28/2.8 rocked slighly on my Bessa T. At first I thought OH POOH--but now I don't use that lens with that particular camera. (None of my other Leica lenses rock on the T, except in the current slang-metaphorical sense of the word.)

I remember years ago I was at a camera where I was trying a Leica 20/ 2.8 on my CLE and the Leica rep. said that I needed to turn the lens a fraction toward infinity because of the slight focal plane differences between Minolta and Leica. Well, when I use my Leica 28/2.8, Summichron 50/2 I don't do that--I usually don't have time as a street photographer--I always keep it in the back of my mind (as one might the location of an emergency stair case).

This brings up a few interesting questions: (1) Cannot depth of view make up for the slight differences intrinsic to different makers' camera bodies? (2) Does not wear and tear on both lenses and bodies create "mismatches" over the years?

By the way, I've found a "match made in Heaven" in using the Hexar RF with my old Leica 135/2.8 (Voightlander round grip attached to the lens's tripod socket). I especially like a motor when I'm shooting telephoto. The Leica M motor is a problem because you have to put that goggle-eye lens on before loading and then you cannot take it off until you'vre finished the roll. The Abrahamsson Rapidwinder is much better in this regard. Still, I find the combo a bit awkward, especially with the round grip--a problem of not having enough hands. So the Hexar is ideal. And though I've shot wide open I've had good results. But then, perhaps, remembering what that Leica rep. told me years ago, I unconsciously do move the focusing collar just a hair toward infinity.

-- Alex Shishin (shishin@pp.iij4-u.or.jp), January 22, 2002.

Opps! Do notice errors in above in the form of missing words (I'm wriing before breakfast). I met the Leica representative in a Camera STORE--I wasn't miniturized and did not meet little Leica representatives inside a Leica camera. Also, to clarify, I've used Leica lenses (28/2.8; 50/2, 35/3.5) on my CLE with no apparent problems. I also use a Minolta 90/3.5 on my Leicas. Focusing it is easier than on the CLE's smaller finder. In 100% of those shots edge sharpness is not an issue. But thanks to this discussion I'll keep in mind that it might some day be. Thanks all!

-- Alex Shishin (shishin@pp.iij4-u.or.jp), January 22, 2002.

Geewhiz, c'mon everyone. Stick your V'lander on the Leicas and Russkies on the V'ander Bessas! I hope that we can find a better thing to talk about :)

Never had a problem focusing a M or LSM compatible lens to each other. I think that we should continue to enjoy shooting without worrying about a mere .00000009 mm differential. I think that handholding the shots already quiver out that difference already :)

-- Alfie Wang (leica_phile@hotmail.com), January 22, 2002.

A discrepancy of 0.09mm in the focusing plane can be of critical importance if it means that when the lense is focused at infinity its plane of focus is before the film plane. Since any image past the infinity point of focus of any lense is quite distorted. So, it is important to know whether 0.09mm is negative or positive in relation to the Leica M 27.8mm lens to film plane registration.

-- Jacinto Lirola (jacinto@snet.net), January 24, 2002.

I've shot with V'landers on Leica, V'landers on a Hexar, a Hexanon 50 on Leica, and Leica lenses (21/35/90) on a Hexar. In all cases, when focused on infinity the rangefinders lined up and the sharpest part of the picture was in the far distance. With 15mm, 21mm, 25mm, and a 50mm at f/2, if there was a back-focus inconsistency it would have shown up clearly. (And before you mention depth-of-field, remember that wide- angles move only a tiny distance to focus from infinity down to 1m - .09mm is a mcuh bigger percentage error for a super-wide than for a 50mm)

What Konica said was they wouldn't warrant Leica lenses would work on the RF. Well, Nikon won't warrant that Sigmas/Tamrons/Vivitars will work on their bodies either. It's just self-preservation in a litigious society (and also helps sell your own lenses!)

The Hexar (due to the .6 finder and slightly sloppy RF optics) is not reliable (IMHO) with anything longer than a 50, including Konica's own 90. And some of them came out of the factory with misaligned RFs, which will give poor results with ANY lens at ANY distance.

So I'm sure some folks got bad results mixing and matching - I just wouldn't bet the farm on 'optical incompatibiliy' being the reason.

-- Andy Piper (apidens@denver.infi.net), January 25, 2002.

This is a really good discussion! Importantly, we are getting really good (albeit informal) field feedback. Looking back at Erwin Puts's bench test, from which I quoted above, I have serious misgivings that I should have had from the beginning. What I think I'm seeing seems so obvious now that I wonder if I'm misreading something.

Anyway, correct me if I'm lost at sea, but here goes.

Erwin Puts writes: "The truth is this: I did a test on the bench and focused carefully on maximum image quality. Then I used a micrometer to defocus by 0.03mm (which is quite small). In the image the loss of contrast was very evident, but resolution at least at the lower frequencies (around 40 lp/mm) did not suffer. What did suffer was the edge sharpness. " My question: What camera did he use? I deduce that if he had to "defocus by 0.03mm" he was using a Hexar RF. What hits me (duh!) is that if his purpose was to warn us not to use Hexar lens on our Leicas, etc. he should have used the 35/ 2 Hexar on a Leica and focused to the correct Leica focus and then compared his results with those of the same lens focused correctly on the Hexar RF. Then he should have taken the 35/2 Hexar and tried it on a Voigtlander Bessa T.

This seems so obvious to me that I wonder again if I am not missing something.

Any thoughts???

It would be nice if we could use Hexar lenses on Leica and Voigtlanders without anxiety.

-- Alex Shishin (shishin@pp.iij4-u.or.jp), January 26, 2002.