I've added a new topic to the FAQ concerning the issue of whether the Hexar RF is compatible with Leica M lenses:

http://nemeng. com/leica/010ba.shtml

Of particular interest is the full text of a recent letter from Mr Herbert Keppler (from US Popular Photography magazine) which confirms Erwin Puts claims that the Hexar RF back-focus is slightly too long, and hence incompatible with Leica M lenses.

More food for thought (and bickering and arguing and …)

-- Andrew Nemeth (azn@nemeng.com), May 17, 2002

Answers

thanks for sharing /pat

-- pat (modlabs@yahoo.com), May 17, 2002.

How can we ever thank you for this, Andrew...

-- Paul Chefurka (paul@chefurka.com), May 17, 2002.

I think quite a few joint Leica / Hexar RF users who do proper tests now all this already. But we are not media GODS so no body takes any notice of our postings. The point I want to know is a point made by Dante that the difference in focus point was corrected on newer RF bodies, so that RF matches the Leica back focus. If this is correct than in the future there has to be 2 sets of Hexanon lenses for the RF to cover the old and new back focus distance RF bodies.. Any comments ??

-- sait (akkirman@clear.net.nz), May 17, 2002.

Hello,

I guess that confirm's it! All the pictures I have ever taken and ever will take with my Hexar RF and all the leica lenses I use are CERTIFIED INCOMPATIBLE PHOTOGRAPHS.

No argurment here. No bickering. It is absolutely IMPOSSIBLE to take a CERTIFIED COMPATIBLE PHOTOGRAPH with this combination.

So don't anybody do it. Don't ever even think about using the 50mm f2.0 summicron on the Hexar RF. If you will do, the picture will be INCOMPATIBLE. There will only be 22 lines per millimeter. If you had taken the picture with an M3 or Voigtlander, you will have a CERTIFIED COMPATIBLE "57" lines per millimeter.

I'm starting right now erasing all the extra lines in all my pictures. This will take a while; because thirty lines per millimeter per lots of pictures will take a very long time. But its worth it. If anyone ever found out that my pictures were CERTIFIED INCOMPATIBLE PICUTURES, I would be drummed from the corps.

O the humanity! O the shame! Horror, O the Horror!

-- David Smith (dssmith3@rmci.net), May 17, 2002.

1) Thanks for the link, Andrew. As usual nemeng.com is the place to be.

2)...BUT. This raises the following question.

My 90mm lens moves about 7 mm to focus from infinity down to 1m.

My 35mm lens moves about 1.5 mm to focus from infinity down to 1m.

A big (1mm) back-focus incompatability should have far more effect on the 35 (focusing it at 1 meter when the RF sez infinity or vice versa) than on the 90 (where a 1mm error is only the 'distance' of infinity to 30 feet or so).

So how come my Hexar RF(s) worked fine with a 35mm (and even a 21 - where 1mm is the ENTIRE focus travel) and yet was consistently OFF with the 90?

Oh, well...

-- Andy Piper (apidens@denver.infi.net), May 17, 2002.

This is very interesting; but only a couple of samples of data points...

I wonder if the Hexar designers made it slightly off on purpose,,,,Just like how the Germans made the pitch of the LSM not 1 mm but 1/26 of an inch; to throw off the copycats...

-- Kelly Flanigan (zorki3c@netscape.net), May 17, 2002.

With due respect to Mr. Keppler, I think there is a flaw someplace in the measuring. He reports a 1.1mm offset, or about .043-.044 of an inch. That is enough to make the 90mm lens when set to infinity, actually focus at 25 feet, and DOF to infinity would be at about f/45 using hyperfocal.

Actual results don't support this.

Erwin suggests about .2mm or .008-.009 off the mark. This is more like it.

I wonder however, if the quality control has just gone to crap over at Konica...

-- Charles (cbarcellona@telocity.com), May 17, 2002.

I forgot to also mention - nobody yet has told us HOW they measured the backfocus, which is a very hard thing to accurately measure. My experiments years ago show that the actual backfocus is theoretical, not some actual mechanical point, and film is neither flat nor evenly bowed.

This is sort of like headspacing a rimless cartridge, its not easily done with ordinary tools, and even the proper gauges are often off by a bunch. Refer to the print of a gauge to see why... they're a #@$#@$ to make!

-- Charles (cbarcellona@telocity.com), May 17, 2002.

I also wonder why they didn't measure the resolution with the lens set to infinity as opposed to 8 feet. That would have taken one more variable out of the equation, and made the effect easier to measure as well. A wide angle lens wide open set to infinity ought to demonstrate the problem (if it exists) pretty conclusively. If I get the time I'll try that experiment.

A whole millimeter seems like an awful lot. If that were true, all images focussed at infinity would be noticeably fuzzy, and that's just not the case.

-- Paul Chefurka (paul@chefurka.com), May 17, 2002.

I guess all those pictures I took with my Leica 35/2 wide open at close focus aren't really in focus like they look.

-- Pete Su (psu@kvdpsu.org), May 17, 2002.

The standard deviation of the lens flange to film rails on all my seven Russian LTM clones is about .002 inch from the 28.80mm Leica standard...I have a 1.000 00" gage block to check my Mitutoyo equipment..several of them are on the money; and some are .001 &.002" off..One is .005 off....I would believe that the HEXAR might be built to higher standards than some of these 25 to 100 dollar EBAY Russian gems I have.......Being 1 mm off is a gross error; maybe an idot ran the test; or someone with no testing/measurement skills.....This is old technology stuff; Henry Ford used JO blocks and measured to .0001 inch in the 1920's......Kelly

-- Kelly Flanigan (zorki3c@netscape.net), May 17, 2002.

Remeber Kelly, that the rails may, or may not be, the backfocus distance. The inner rails hold the edges of the film, but depending on the rail geometery and the backplate, the _actual_ backfocus may be somewhat different. I've never measured the rail to flange distance on any of my M's, but if I were to make that measurment, it would be with height gauge on the rail, with the flange held against a surface plate.

BTW, on any of your dial calipers, you ought to check them at 12,3,6 and 9 o'clock dial points. I've found none that were OTN (on-the-nuts) at all 4 points, but have found many that were OTN on all but one point.

There are laser reflective devices for low pressure measurements. I wish I still had access to that sort of equipment, but.. I don't.

-- Charles (cbarcellona@telocity.com), May 17, 2002.

Must be that my Schneider APO loupe knows whether a slide was taken with the Hexar or Leica and automatically adjusts itself so they both look tack sharp to my eye. I mean, Erwin and Herb Keppler can't be wrong.

-- Jay (infinitydt@aol.com), May 17, 2002.

Charles; My measurements were from the inner rails were the film touches to the lens flange.. The Zorki 3C, 4 & 6 of mine have 2 sets of rails; the FED 2 (two from Anya); FED 3 ; & FED 5B of mine have just one set of rails...The motor drive Leningrad has 2 sets of rails.. The FED 2 models are so basic that one can place a calipier directly across the lens flange and film rails...

-- Kelly Flanigan (zorki3c@netscape.net), May 18, 2002.

Jay; Is that the special collector version of the Loupe; the Jason Schneider Model? ; with the Zorki option?

-- Kelly Flanigan (zorki3c@netscape.net), May 18, 2002.

Andrew,

I think the question of Hexar RF back focus is largely settled through experience.

The measurements allegedly “proving” this problem are totally irrelevant as amply demonstrated by the difference existing between them as Puts found a much different value and “Popular Photography” published a value which (on the contrary to Puts’ one) will imply you can never have an in focus shot when set at infinity whatever the lens used at whatever available aperture on a Leica lens (someone mentioned here f/45 as the widest possible aperture to obtain anything sharp at infinity).

Moreover to compare valuably the measures, they should have been done according to the manufacturer’s reference points in both case. Who knows which are this reference points ?

Then the testers should have measured the distance on a randomly selected batch of both bodies and averaged their measures (just to establish more or less the tolerances used by each manufacturer and be more convincing).

As there are different types of film support depending not only of the maker but even in the range of each maker, the behavior of the film is likely to be different under the same pressure from the pressure plate and the shape of the rails. This induce a margin of error which should be tolerable and as far as I know, this has not be made public by any manufacturer.

As far as I’m concerned I’m using the Hexar RF with two Leica lenses: 35mm f/2 Summicron (old generation made in Canada) and 135mm f/4 Tele-Elmar and an Hexanon-M lens: 90mm f/2.8 M. In NO CIRCUMSTANCES, whatever the distance and fully open one of these lenses failed to be in focus when properly handled (verification done under a 8x magnifier and negatives blown to 30 x 40 cm…

For me it is a much better way to test than any erratic pseudo- scientific measurement which is done without clear references.

In most cases, the focusing problems of early Hexar RF batches was traced to an improper rangefinder alignment which is easily corrected by any good shop.

Now, as to the tolerances which must be admitted, I think we have to remember what Leitz itself admitted when they issued converting rings from LTM to M mount for their LTM lenses. Nobody ever complained the LTM lenses didn’t focus properly with these converters and I’m sure the tolerance of manufacturing of these rings are certainly superior to what Puts indicates as the back focus problem for the Hexar RF. Nobody has said the present V-Länder lenses which need both to be mounted on a Leica M and now on the Bessas T and R2 (and Hexar RF) with such a converter doesn’t focus accurately.

Add to this the influence of dilatation and contraction due to the changes in temperature and I’m sure you will understand the alleged back focus issue is nothing more than a bullshit.

What is absolutely certain is some people might have a real interest spreading this kind of tales. In fact, both Leica and Konica. Konica (who tells in the instruction booklet the compatibility is guaranteed only with their lenses) because as far as it is known a fair amount of their lenses are staying on the shelves taking dust at least in Japan (the users buying Leica – or V-länder – lenses instead) and Leica, more over with their new model, because a sizeable number of customers may think twice before buying a grossly overpriced M7 which offers very few to convince the average customer to spend twice the price of the Hexar RF.

The fact Erwin’s measurements are much less divergent from what he thinks to be Leica norm is also a demonstration. I have no doubt of Erwin’s sincerity and independence (on the contrary to what was said here and there) but the measurements he took are insufficiently demonstrative nonetheless as only a very precise laser device used in accordance to both manufacturers official procedure and averaged on more than one sample of each body should have approached a kind of objectivity. And even then, the difference is very, very small… As to “Popular Photography”, knowing to well the influence of the advertisers on a publication and taking into account the absurd value published (which will be probably rectified in small characters in a future issue to give it a tad more credibility) I think we are facing a deliberate intoxication.

Finally, Leica fundamentalists (which means for me something different from Leica fans) might like it or not, we have a SFRF Leica lens compatible camera priced less than half an M7 which is despite some shortcomings (compensated by some advantages) and limitations (two lenses from Leica range are liable to induce focusing errors at full aperture due to the finder magnification, but no more than the 0.58 version) is a valuable alternative to the Leica M7 body. I understand this is a shock to them but this is it… As long as they will sleep at Solms and keep their largely obsolete way of assembling their cameras with the associated high costs and grossly overpriced retail prices, the only way now to maintain sales others than the ones generated by “special series” and collectors- investors interest is to pretend their camera bodies are still the only game in town. As long the Hexar RF owners will prefer the superior Leica lenses to the M-Hexanon ones, Konica will have interest to pretend their bodies are not Leica compatible. This is the true origin of these allegations. Remember also Erwin Puts revealed publicly for the first time what both manufacturers denied : there were actually negotiations between the two manufacturers and they failed to reach an agreement… I sincerely doubt Konica then altered the design of both their body and lenses just to make them incompatible…

Friendly.

François P. WEILL

-- François P. WEILL (frpawe@wanadoo.fr), May 18, 2002.

WELL! All my training at art school and 20 years of shooting never prepared me for this techno-licious discussion. So, all you nerds, answer me this: Can I, or can I not, focus a Leica 21mm/2.8 Asph lens on a Hexar body? I've already lost confidence in the loading abilities of the Hexar (previous thread). Then Francois spent 1000 words convincing me to give the Hexar another go...NOW THIS! 21mm on a Hexar? Or is it better on a .058? In 20 words or less please, ( like children, we artistic types have short attention spans ).

-- Marc Williams (mwilliams111313MI@comcast.net), May 18, 2002.

My not too objective observation. I can't argue with those who are technically minded here on this forum but pictures taken with my RF on a 35mm f2 asph came out sharp. This could be due to the dof or not I really do not know. I do however feel that the timing of the so call "confirmation" by H Keppler is questionable. The 'confirmation" came on or about the time of the launch of the M7. I mean it has to come out now and not when Pop Photo was testing the RF in one of its previous issue. Was Pop Photo that inexperience as not to forsee that there would be people buying the RF to use their Leica lenses. Nothing was said if I remember correctly about compatability issue. Then all of a sudden when the M7 was about to be launched, out came this "confirmation" by our expert. Even the figures differs from those of the other expert. So which is more correct or are both of them incorrect? For Konica to have a failure in the RF is well probably not good (they have other divisions to cover the failure and making cameras are only a small part of it) but for Leica to fail again (remember M5) it could prove to be quite painful. Leica has to make the M7 viable in the presence of the more advance RF (though some will say I am wrong)which is quite a task. To me all this differences between the RF and the Ms has more to do with advertising than with the actual problem. It makes sense for Leica to say that to make use of their lenses (which I agree here are better than the competition but at quite a high cost) you must use their cameras and not some other cheaper brands. The marketing side of Leica has to make the M7 financially viable and also for those who bought the M7 or about to buy the M7 that the M7 is THE ONE and not a cheaper camera that can do the job better. I have my doubts and feel this is one of the publicity stunt by Leica which has no bearings on the performance of the RF when using Leica lenses. I cannot forsee the future but should Leica decides to make only lenses like CZ, I think their literature will say that M lenses can be use on all RF cameras that adopted the M mount. Regards/wong from Malaysia.

-- wong kh (dosi@pd.jaring.my), May 18, 2002.

A couple of points; It's again only a test of one body - give me an average with measurements from 10 bodies and we are getting near what could be called a 'scientific' test. The errors on the M3 and the Voigtlander are just as significant! - - distances that WILL cause focus errors! the Voigtlander is just as far out in the other direction and the M3 is out by more than the thickness of a film emulsion. Here's a quick test that involves basic equipment and will reveal the errors in focus at "LESS" than the errors measured here; with a bit of ground glass on the inner rails of your camera focus the lens (pref a 50 or wider) wide open with a powerfull loupe (8-15x) - now cut a bit of film into 'window' and put it between the glass and rails so you are in effect moving the focus plane by aprox .15mm - now check the focus again - I garauntee you will notice a difference and it wont be small.

-- Johann Fuller (johannfuller@hotmail.com), May 18, 2002.

My friend has a Noctilux, 75/1.4 Summilux and a 90/2AA which he uses on his two Hexar RF bodies. He has no problems focusing close with the lenses wide open. He also has many wide angle lens 12/5.6, 15/4.5, 15/8 (original M mount Hologon) and at least three different 21s. All these lenses work with no problems. If it works, it is not broken and does not need to be fixed.

-- John Collier (jbcollier@shaw.ca), May 18, 2002.

In examining the lines per millimetre resolution of the Kodak T-Max 100 film with the lens set precisely at 8 feet, we were able to produce 57 lines per millimetre at the center with the Leica M3, and the Voigtländer camera, but only 22 lines per millimetre with the Hexar. We therefore concluded that the Hexar lenses and cameras are not interchangeable whatsoever with the Leica M3 and the Voigtländer cameras.

It would seem to my simple brain that if i want Leica lenses true quality i would be better with a Leica body,just have to keep saving..oh well, i suppose cheaper easy options never really work.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

If I worried this much about my equipment, I probably wouldn't have many photographs.

The Cook, Hexar RF+Leica 35/2, Copyright 2000 Jeff Spirer

-- Jeff Spirer (jeff@spirer.com), May 18, 2002.

C'mon Jeff,

Imagine how much better she'd have looked if you'd have used an M3 body. I can "see" the missing lines/mm from across the room.

-- David Smith (dssmith3@rmci.net), May 18, 2002.

the missing lines/mm from across the room

Of course Dave this is very easy to spot on a low reg computer monitor...mm i can count them 1234

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

The point was missed, not the lines.

-- Jeff Spirer (jeff@spirer.com), May 18, 2002.

Jeff Spirer

We all like the best quality image we can obtain it does not mean we are obsessed with gear.I remember a post by a certain Mr Spirer who only wanted to take a M/F to China to ensure he got the best quality images.Yes, Mr Spirer.

Friend Regards Allen

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

That's not what I said at all in the China thread. Stop inventing things, just like you did on that thread.

-- Jeff Spirer (jeff@spirer.com), May 18, 2002.

What did you say,i presumed you only wanted to take a M/F for quality was i wrong to think that.You say, and i may be wrong that you would only take a M/F TO CHINA.Perhaps you could point the way to this posting as you are more savy on these things than me.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

By the way i do not invent things.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

Jeff Spirer

And what have i invented on this thread please tell.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

Still waiting with interest.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

Good God you're a moron. You said that I wasn't showing a photograph taken while moving, when in fact, I had documentation that I had.

I didn't say that I took medium format because it was "higher quality," I said I took it because I could print larger. Those aren't the same thing.

Take a break and learn to use a camera. Come back afterwards. You obviously have little to do except play games on the internet.

As I said in that other thread, you're an ass. And you seem to enjoy demonstrating it.

-- Jeff Spirer (jeff@spirer.com), May 18, 2002.

Good God you're a moron.

I will not demean myself to answer in the same way but once again point to the post you are usually very good at that sort of thing.We can all call names try to prove your point in sensible way if i am wrong i will be the first to admit it.I am doing my best to be nice.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

said I took it because I could print larger

Is not that something to do with a bigger neg which allows you to achieve a sharper enlargement with less grain.Therefore the viewing quality of the print would be better quality.Why do you feel the need to insult folks if they disagree with you.Have i ever called you names.The only other person who likes to call names and insult people i have noticed is Phil,usually when he has a few beers.

-- Allen Herbert (allen1@btinternet.com), May 18, 2002.

You know, there may be something true about this. I cannot seem to get my pictures in focus. Look at that guy in the back, I can barely see him.... Hexar + 35mm Ultron

-- Nick (nicholas_rab@hotmail.com), May 18, 2002.

Both pics sucks. That's what. Im with Allen on this one.

-- Lux (leica@sumicron.com), May 19, 2002.

They looked ok. post some of yours. regards/wong from malaysia

-- wong kh (dosi@pd.jaring.my), May 19, 2002.

Lux, you are obviously a giant of the critical world.

-- Jeff Spirer (jeff@spirer.com), May 19, 2002.

Ah, another thread ends with name calling and "Your pix sucks" comments. I love the internet!

-- Hadji (hsingh@quest.com), May 20, 2002.

Come on guys, stop with the childish name calling already. Jeff, you need zero validation from anyone here. You've the courage to post images, and for that you are to be commended. To my Art Directors' eye the images you showed on this thread MAY have been improved upon with a little cropping to un-center them a bit, or to increase the design dynamics. But that is a purely subjective response I have based on my design training and experience working with thousands of images in my job. Hypothetically, If you submitted them to me for a job, I would discuss such things with you, and reveal why they seemed important to the image in context to it's use. I'd hazard a guess that name calling would most likely NOT be part of that exchange.

-- Marc Williams (mwilliams111313MI@comcast.net), May 20, 2002.

I conducted a series of tests between my M6 and Hexar RF using the 35/1.4 asph wide open at infinity on Velvia (tripod, cable-release, etc.).

I am able to detect the following differences under a high powered (22x) loupe:

-- trees and houses on a hillside several miles away are indeed sharper when shot with the M6 than the Hexar;

-- a line of bushes about 50 yards away are noticeably sharper in the slides shot with the Hexar than the M6.

This would seem to corroborate a very slight back focus difference between the two, causing the Hexar to focus short of infinity. However, the difference is so slight that it requires the 22x loupe to notice it (even then it takes quite a bit of scrutiny); under the 5x Leica loupe, no differences can be seen (to my eyes, at least), nor can I detect any difference in the slides when projected to fill my 50" screen.

The Hexar RF is such a fine compliment to the M6 that I would not part with it based on the miniscule differences I've seen with my own tests. For my style of shooting--generally candid street shots-- these very slight differences disappear altogether, anyway.

If you are looking to substitute medium format equipment for 35 mm rangefinder gear, I'd suggest you stick with Leica lenses on Leica bodies; otherwise, don't worry about it. In any event, you can always conduct your own tests with your own gear to determine if there is indeed a problem--no need to take others' word for it.

Cheers, Dan

-- Dan Honemann (dan_honemann@yahoo.com), May 20, 2002.

What a fuss. I suspect that that even if the Hexar is not technically able to focus, say, a 50mm Summilux close up at full aperture, most of the time the error may well be compensated for by focussing inaccuracy of the operator. Likewise when someone says their image taken with a 35/2 at full aperture is sharp, then probably the dof for the lens is sufficient to cover that kind of innacuracy. The Hexar might still be inaccurate though and this will worry some people. It is one thing to be able to blame your technique, but being able to blame the camera is worse for your psyche and peace of mind.

-- Robin Smith (smith_robin@hotmail.com), May 20, 2002.

Leica bodies are based on an assumption of a 27.95mm distance to the pressure plate rails, a 0.20mm film channel, and a 27.75mm front rail. Hexar bodies have a 28.00mm distance to the pressure plate rails, a 0.24mm film channel and a 27.76mm front rails. The question is what assumption is made about where the film sits - front or back.

-- Dante Stella (dante@dantestella.com), May 21, 2002.

There could many human errors possible to do the these kind of testings.
May I suggest the following testing methods to reduce human errors:
1. Use Leica M6 .58 vs Hexar RF. They have the closest VF Mag.
2. Use slide film.
3. Use Tripod, cable release.
4. Use same lens 50 'cron or 35 'cron at same aperture/shutter speed.
5. Take 10 shoots for subject at about .7m, 2m, 3m, 5m, and inf. Reset the distance to inf and then refocus for each shoot.


-- kenny chiu (gokudo31@hotmail.com), May 21, 2002.

An addition to Kenny's fine list is:

:(6)to vary the exposure; ie bracket the shutter speed...

-- Kelly Flanigan (zorki3c@netscape.net), May 21, 2002.