Jump to content
Sign in to follow this  
glenerrolrd

Are M lenses really interchangable?

Recommended Posts

Advertisement (gone after registration)

That being said, a lot of the complaints are about rangefinders and lenses that were way off. There is this thread right now where the owner's Noctilux was off by about 80mm when focused at 1120mm and used at f2.8:

 

.

 

Alan,

 

I think it was me and it was worse than that. When my Noctilux came back from coding service, it was 1.5+ meters - yes 1.5 meters not centimeters off at 8 meters. I am pleased to say it is fine now after its second visit.

 

Wilson

Share this post


Link to post
Share on other sites

Do Leica test lenses individually after they change the mount for coding?

/applications/core/interface/imageproxy/imageproxy.php?img=http://tinyurl.com/rv7w/question3.gif&key=a19c272005e6f9efc6b25040f1563c538d755e4f01ce982c014ff1f5b568ffe3">

Share this post


Link to post
Share on other sites
Do Leica test lenses individually after they change the mount for coding?

/applications/core/interface/imageproxy/imageproxy.php?img=http://tinyurl.com/rv7w/question3.gif&key=a19c272005e6f9efc6b25040f1563c538d755e4f01ce982c014ff1f5b568ffe3">

 

That is a question that hasn't been answered. I think they do on some lenses and don't on others.

the reason I say that is I sent in 2 90mm Tele-Elmarit's, one newer (has the 90 marking in yellow on the lens barrel) and one older (no 90 marking on the barrel), both made in Canada. I got a call from Leica NJ that the older one had to go back to Solms for the coding and the other, the newer one, I got back about 3 days after the call about the older one. From looking at both lenses before sending them in they SEEMED to have the exact same bayonet mount and screw placement. The only reason I can see that the older one would need to go back to Solms is when putting the new coded mount on the older one it did not meet specs and or focus correctly. They wouldn't of known that unless they did some type of check on it. Now it could of been so far out when checked or the old mount was thicker or thinner then the new coded one that they knew that it wouldn't work correctly. So they sent it off to have the mount milled to match the original. I won't know if it focuses correctly until I get it back. It was about a month ago I got the call and it got sent back.

God only knows when I will see that lens again.

Milling the mount to the same spec as the original does not guaranty it will focus correctly. It just guaranties that it will be the same as it was before the mount was changed.

I honestly don't think they check them. If they do that is no guaranty as I have 2 NEW lenses that don't focus correctly. So if new lenses go through checking and calibration and they are still off then the check they do on older lenses after coding will suffer the same inaccuracy.

Share this post


Link to post
Share on other sites
Do Leica test lenses individually after they change the mount for coding?

/applications/core/interface/imageproxy/imageproxy.php?img=http://tinyurl.com/rv7w/question3.gif&key=a19c272005e6f9efc6b25040f1563c538d755e4f01ce982c014ff1f5b568ffe3">

 

MIne was not just a coding but a coding service but still the answer was obviously not even in that case. I rather cynically posted, when I was told my Noctilux was in final technical checking after its second visit.

 

"Hey Hans - does this look like a black Noctilux to you?"

 

"Ja Georg - it looks like a Noctilux to me"

 

"Ok then passed final testing - send it out."

 

Wilson

Share this post


Link to post
Share on other sites
Graham I believe you are correct that you can have a fully interchangable lens system. If could share with us two things 1. How did you satsify yourself that your camera / lens was focusing properly? In otherwords what do you believe should be reasonable expectations for focus accuracy and how did you get comfortable . 2. Ultimately where any of your lenses requiring adjustment and did you have them matched to your specific bodies? Same as above ..how did you accomplish this.

 

Hi Roger,

 

1:-

 

I tested at 3 ranges, 1meter, 5 meters and infinity. I used a focus chart at 1 meter and at 45 degrees, tripod and self timer release.

 

I tested the following lenses wide open:- 50 1.4 lux, 90 4 elmar, 28 2.8 elmarit, CV 50 2, CV 40 1.4.

 

If the point I focused at was within the DOF area and therefore was in focus on the final image I considered this an acceptable result.

 

At 5 meters I used a yard stick attached horizontally to the wall and at infinity I checked the range finder images coincided with the lens at end stop.

 

I used bracketing at 1 meter and 5 meters to qualify my results.

 

I tried a 1.25 magnifier, which made in easier to align the images in some cases but still resulted in an out of focus result with the faulty cameras.

 

My eyesight is 20:20 at 2 meters.

 

2:- No

Share this post


Link to post
Share on other sites
Alan,

 

I think it was me and it was worse than that. When my Noctilux came back from coding service, it was 1.5+ meters - yes 1.5 meters not centimeters off at 8 meters. I am pleased to say it is fine now after its second visit.

 

Wilson

 

Actually it was someone else named, "jedi996sps" So that makes at least 2 owners with an extreme focus problem with this lens.

Share this post


Link to post
Share on other sites

Advertisement (gone after registration)

I dont understand your reasoning? If what you say is right then what on earth is the point in my buying a 50 1.4 if you are saying it can never be focused reliably at f1.4 ???

 

I know it can be done because I can get repeated accurately focused shots at 1.4 with the body I have at the moment (electrically faulty)

 

I can do it too. But at 3 feet only about 25% of the shots are within 3 or 4 mm of the eye I was trying to focus on. You have to realize that the 50mm Noctilux or 75mm Sumilux are EXTREMELY difficult to achieve consistent focus because of subject and camera movement if nothing else. To some extent, no matter how good you are, or how well collimated your lens/camera is, you have to be LUCKY to get even half of your shots focused on that pimple on the cheek.

Thats just the way it is.

 

Now an admission. I know my camera is fine. I have checked it against a reference lens I have had for many years. I also know that, except for the last two purchased, my other lenses are within my tolerance band except for the 21mm Kobulux (which I have never bothered to fix because of the extremely wide DOF). I have a large machine shop so I am able to check the flange to sensor distance and it too is within specs (actually quiet easy).

 

From a practical point of view, if all (or most) of your lenses seem to be consistently backfocusing by more than an inch or two I would be much more suspecious of the camera body not the lenses. If I had a wonky camera body I would send it to DAG, not Leica. Some of the folks in Solm are fine, others have a bad day. Don never has a bad day(at least that he lets effect his work). And anyway who wants to wait for months?

 

My lenses are an eclectic mix. I have everything from late 40s Leica,Canon and Nikon lenses to the latest offering from VC and Zeiss. For the most part, the lenses are fine.

The Kobulux does backfocus about 4" but they all do. One of my 135mm Canons was totally wonky but it had been assembled incorrectly during a CLA (thanks Ferider for fixing it!). Other than that, they are all just fine. That is not to say that specific lenses might have weird problems. The thread about the 35mm f1.4 is an interesting read.

 

It is possible that Leica is having a QA problem with regards the flange to sensor distance. It is certainly something that should be easy to adjust accerately. The rest of the rangefinder adjustment is more of a trick. Frankly, I have my doubts that Leica has it together enough to achieve 100% consistent results. That being said, I think a lot of people are being too critical than the situation warrents

 

Rex

Share this post


Link to post
Share on other sites
Guest tummydoc

I have one M8, but more than 100 Leitz/Leica lenses in bayonet and thread mounts. I have not gotten round to testing more than 20-30 but have not found any consistent mis-focussing. I am sure that people reporting problems are not hallucinating. The M8 to-date is populated with problem cameras in a wide range of categories, so the probability is that mis-aligned rangefinders and mis-calibrated body-to-sensor registers are amongst them. My experience is that Leica's QC has been spotty if not sloppy during the past decade to two decades, so any lens produced since the late 1980s would not surprise me in the least if it was out of specification. The M8 magnifies the issues for a number of reasons. One is that the rangefinder magnification has been lowered from 0,72 to 0,68. That makes accurate focus with longer and faster lenses more problematic. Add the crop factor which has us effectively magnifying every focal length by 33%. Add the fact that the Leica viewfinder is not projected at a fixed virtual plane as an SLR, those whose eyesight requires different correction factors to see sharply at different distances will not have equal focussing acuity throughout the range of subject distances. Add still the fact that digital sensors are much flatter than film and thus do not [unintentionally as it were] ever compensate for curvature or field. Finally, add the fact that with digital most tend to examine the results at much higher magnification than did with film. The upshot is that of the multitude of instances of "backfocus" or "front focus" there are also undoubtedly a multitude of possible causative factors acting singly or in combination.

Share this post


Link to post
Share on other sites
Yes some people have a problem. Is that problem severe or not? We don't know.

 

I'm not holding my breath waiting for Leica to tell us that answer, whether statistically or from a functional standpoint.

 

But I'll give one in the meantime. To a user who buys a $5,000 camera one of whose main raisons d'être is fast lenses and accurate focusing, any backfocusing problem is a big problem. No one ever seems to talk about front-focusing, which is a dead indication that there is a systemic issue with some types of lenses, not some situation where some cameras are front and some are back. From what I have been able to observe reading postings, it's always back-focusing and it's always Leica lenses, always fast and usually telephoto. My guess is that these lenses incorporated an RF cam correction for film curl. That probably accounts for the problems with the pre-ASPH 35 Summilux, too.

 

Whatever the problem, it is compounded by Leica's backlogged service (currently more than a month in the USA), which then puts this expensive camera and its lenses out of action for weeks at a time while someone tries to figure out what is going on - apparently taking more than one try in a lot of cases. What should we all do? Keep buying additional bodies until New Jersey or Solms gets things straightened out? Until the Leicas decide to adequately staff their repair facilities? Get our film Ms back from the people we sold them to in order to buy M8s? Have C-41 labs scratch up negatives for us to painstakingly scan and patch up later?

 

The only time I ever had a problem like this on another camera (there, consistent front focus), it was a D2x that wasn't quite up to focusing a 28/1.4 Nikkor. Nikon adjusted both items (free of charge) in a two-week total turnaround - and it wasn't even through NPS. That's the essence of "compatible" - either it works out of the box or the company selling the camera makes it right with a minimum of disruption.

Share this post


Link to post
Share on other sites
I'm not holding my breath waiting for Leica to tell us that answer, whether statistically or from a functional standpoint.

 

But I'll give one in the meantime. To a user who buys a $5,000 camera one of whose main raisons d'être is fast lenses and accurate focusing, any backfocusing problem is a big problem. No one ever seems to talk about front-focusing, which is a dead indication that there is a systemic issue with some types of lenses, not some situation where some cameras are front and some are back. From what I have been able to observe reading postings, it's always back-focusing and it's always Leica lenses, always fast and usually telephoto. My guess is that these lenses incorporated an RF cam correction for film curl. That probably accounts for the problems with the pre-ASPH 35 Summilux, too.

 

Whatever the problem, it is compounded by Leica's backlogged service (currently more than a month in the USA), which then puts this expensive camera and its lenses out of action for weeks at a time while someone tries to figure out what is going on - apparently taking more than one try in a lot of cases. What should we all do? Keep buying additional bodies until New Jersey or Solms gets things straightened out? Until the Leicas decide to adequately staff their repair facilities? Get our film Ms back from the people we sold them to in order to buy M8s? Have C-41 labs scratch up negatives for us to painstakingly scan and patch up later?

 

The only time I ever had a problem like this on another camera (there, consistent front focus), it was a D2x that wasn't quite up to focusing a 28/1.4 Nikkor. Nikon adjusted both items (free of charge) in a two-week total turnaround - and it wasn't even through NPS. That's the essence of "compatible" - either it works out of the box or the company selling the camera makes it right with a minimum of disruption.

 

Wait a minute. When I say backfocusing, I am using the term in a generic way. Just as many of my lenses front focus as back focus. Also my Nikon, Canon and VC lens have about the same amount of "backfocusing" issues as my Leicas.

 

And to say *any* backfocusing is intolerable is going a little far. With real fast lens, on a good eyesight day I can focus to within a couple of millimeters @ 3'. When I am that close, the barrel of the lens barely moves to change the focus by 2 or 3 mm. Even with the fastest lens you got to give 5 or 6 millimeters for tolerance. The Noctalux does have about 12mm of DOF.

 

Rex

Share this post


Link to post
Share on other sites
Hi Roger,

 

1:-

 

I tested at 3 ranges, 1meter, 5 meters and infinity. I used a focus chart at 1 meter and at 45 degrees, tripod and self timer release.

 

I tested the following lenses wide open:- 50 1.4 lux, 90 4 elmar, 28 2.8 elmarit, CV 50 2, CV 40 1.4.

 

If the point I focused at was within the DOF area and therefore was in focus on the final image I considered this an acceptable result.

 

At 5 meters I used a yard stick attached horizontally to the wall and at infinity I checked the range finder images coincided with the lens at end stop.

 

I used bracketing at 1 meter and 5 meters to qualify my results.

 

I tried a 1.25 magnifier, which made in easier to align the images in some cases but still resulted in an out of focus result with the faulty cameras.

 

My eyesight is 20:20 at 2 meters.

 

2:- No

Graham Thanks for your reply ..your approach to testing is very similar to what we were attempting. Did you use the Focustestchart.com or have you found another? We did the best we could to eliminate the photographer error and also used bracketing and extra cameras and lenses to verify our findings. We had the advantage of being able to test a single lens on 4 bodies or a individual body with many lenses. If we got something that looked wrong we re did the test . We did not have much problem in determining if a lens was truely out ..as they were generally above 20mm when they were out. Errors of less than that may be considered either not meaningful or influenced by the lack of testing control. The only thing that might change my opinion on this would be if you do not have a reference standard. If can not confirm that your camera is properly calibrated ...then you can be fooled(by offsetting errors ) as I may have been ..into believeing that certain lenses are either in or out of calibration. Thank you for your contribution .

Share this post


Link to post
Share on other sites
Graham Thanks for your reply ..your approach to testing is very similar to what we were attempting. Did you use the Focustestchart.com or have you found another? We did the best we could to eliminate the photographer error and also used bracketing and extra cameras and lenses to verify our findings. We had the advantage of being able to test a single lens on 4 bodies or a individual body with many lenses. If we got something that looked wrong we re did the test . We did not have much problem in determining if a lens was truely out ..as they were generally above 20mm when they were out. Errors of less than that may be considered either not meaningful or influenced by the lack of testing control. The only thing that might change my opinion on this would be if you do not have a reference standard. If can not confirm that your camera is properly calibrated ...then you can be fooled(by offsetting errors ) as I may have been ..into believeing that certain lenses are either in or out of calibration. Thank you for your contribution .

 

Roger see a new thread started by me.

http://www.l-camera-forum.com/leica-forum/leica-m8-forum/29832-extension-m-lenses-really-interchangable.html

I did some more controlled testing of both bodies and the 50/75/90 lenses and posted images of the tests on my smugmug site.

Ed Chatlos (Shootist) : photos : M8 Lens Focus test - powered by SmugMug

Share this post


Link to post
Share on other sites
Do Leica test lenses individually after they change the mount for coding?

/applications/core/interface/imageproxy/imageproxy.php?img=http://tinyurl.com/rv7w/question3.gif&key=a19c272005e6f9efc6b25040f1563c538d755e4f01ce982c014ff1f5b568ffe3">

 

I have heard from a Leica Exec that the delay in changing mounts are two fold, 1. inventory of the mount and 2. Testing the lens for correct flange to film distance.

 

I agree with Roger that on our trip I saw a great deal of variances in the rangefinders, some were out vertically others had adjusted them using the allen wrench to get them back into their spec. I have been shooting Ms for the past two decades and have adopted the f8 school of shooting and have used it on the M8 as well. Why? because with a 35 (now 28) the subject will be within a range of focus that compensates for the slop in a rangefinder. Have I tried shooting a film M wide open? Yes, and usually blamed myself for sloppy focusing because I could not shoot, process and blow the image up immediately. Sometimes I got lucky but for the most part I shot at f8 and still try to. Shooting a 75 wide open with an SLR is challenging enough, now put it on a rangefinder, throw in moving parts that can be made useless by too much grease or dust on the cam follower.

 

Am I saying that the hope of shooting wide open with an M8 is not possible? No, just a lot more challenging. QC an issue with M lenses? Maybe, I tested all of my lenses some were from the original M6 days (1986 - 2000) when the going was good for Leica these all were spot on. I have one new lens that is also spot on, 28 'Cron. Could there have been some spotty QC during the dark days of Leica 2001 till 2005? Are we seeing the problems from that vintage of lenses? This could explain why some lenses have to go back to Solms for "other" adjustments when they have been sent in for 6 bit coding.

 

Just my $0.02

 

Al Tanabe

Share this post


Link to post
Share on other sites
As to answering your questions, supplying detailed information and whether you think my discussion is solid enough... I find your tone unacceptable.

Roger, Roger, Roger.

Glance back at that post (you can use the little ">" icon after your screen name here) and check its formatting. Sloppy, sloppy, sloppy!

I find your tone unacceptable.

Then you need to look inside yourself to find out why. I can't do that for you. I can incite, but you need to consider why my tone seems unacceptable. I doubt that you understand, but I'll be glad to send you a brief note on it if you wish. It's a very helpful basic teaching of Buddhism.

As to answering your questions, supplying detailed information ...

Clearly, you've been chastened enough now by others in this thread that you and Ed and others are beginning to do it.

 

Thanks for joining the rest of us in trying to solve the problem!

 

Respectfully,

--HC

Share this post


Link to post
Share on other sites
HC, maybe, but right now, I feel I'm drowning in a kind of mis-alignment soup. Unlike Jono, I've never had the same problems with Nikon equipment.

Mark--

I'm very sorry for the difficulties. You're not usually one to get bogged down by analysis.

 

--HC

Share this post


Link to post
Share on other sites

The whole M8 focusing situation is quite complex. We need to be able to separate lens and camera adjustment issues from each other, and from focus shift.

 

I've been relatively lucky (knock wood, spit over left shoulder three times: ptu, ptu, ptu). Most of my lenses focus properly on my M8, wide open. They also focus on a distant object properly when the lens is set to infinity--I'm talking about the moon, a cell phone tower 1/2 mile from my house, and downtown buildings a mile from my mother-in-law's apartment balcony.

 

I've done infinity tests and tests at about one meter, two meters, and three meters, both on a tripod and off, and my results are consistent. Since the majority of my lenses focus correctly wide open, both close-in and at infinty, I believe my M8 is in proper adjustment.

 

But stop the lenses down, and things get more complex.

 

My 35/1.4 ASPH focuses perfectly at f/1.4 and 2. At 1:1 view, I can see DOF both front and back of the object focused upon. At f/2.8, the object is still in the sharp zone, but just barely. At f/4, 5.6 and 8, the zone of sharp focus moves just a bit farther back than the object focused upon. In other words, the lens appears to back focus when stopped down. These results are similar to what Sean Reid obtained in his tests. So if I use the lens wide open or nearly so, I'm in heaven. If I use it at medium apertures, I'm apt to be disappointed at 1:1.

 

My 50/2 tabbed Summicron from 1983 behaves similarly, as does my 50/1.5 VC Nokton.

 

My 35/2 Summicron (Ver IV, NOT apheric), front focuses at f/2, appears spot-on at 2.8 and narrower at near and medium distances, and doesn't focus at infinity properly until depth of field covers it at f/5.6. It is clearly out of adjustment, and is going to Dr. DAG shortly. But again, it clearly shows a focus shift between f/2 and all other apertures.

 

My 90/3.5 VC Lanthar appears to focus correctly at all apertures and distances tested. But it's a slow lens, by design less prone to focus shift.

 

How significant is the focus shift issue? I can see it even on a 5x7 print if I look hard, and I suspect that it really matters in prints larger than 8x10. Unless you were a member of the Kodachrome-and-tripod crowd, and maybe even then, the M8 shows a level of detail most of us never encountered with film. Certainly not with Tri-X or similar.

 

Note that I'm not talking about gross misadjustments of several inches or more that can be repeatably demonstrated. For those, you need to determine whether it is the camera, lens, or both, and have it fixed. It might be useful to try the same tests on a film M body with slide film.

 

I am sending one lens to DAG. He will adjust it with his M8, which he says is in perfect adjustment. Then I'll check it on my camera. If it's good, then I'll get my other lenses adjusted.

 

It may be that some really fast lenses can only be adjusted perfectly for wide apertures. That's disappointing, but probably livable, since we bought f/1.4 and faster lenses to use wide open. Hopefully there is some reasonable compromise which will allow most lenses to perform well at all apertures. DAG has indicated to me that there is. I asked him if a lens adjusted properly for the M8 would still perform properly on a film body. He said that is should, that we're dealing with smaller tolerances that we did with film. This seems confirmed by reports that Leica is refining its post-adjustment testing procedure in light of the M8 issues.

 

Stay tuned. . . And you're right, all this is a pain in the place where one sits.

 

--Peter

Share this post


Link to post
Share on other sites
Do Leica test lenses individually after they change the mount for coding?

/applications/core/interface/imageproxy/imageproxy.php?img=http://tinyurl.com/rv7w/question3.gif&key=a19c272005e6f9efc6b25040f1563c538d755e4f01ce982c014ff1f5b568ffe3">

 

Probably not considering I got my 28 summicron back with a 24mm mount on it. Or Leica has a program (honorable but misguided) program of hiring the blind! Funny thing is that the lens also had a problem with infinity focus being off - that was fixed but with the wrong lens mount.

Share this post


Link to post
Share on other sites

Charles: I remember a cartoon in a Seattle newspaper years ago, when Boeing was at a production peak. It showed a jet aircraft being assembled with parts of it upside down, backwards, etc. A guy with a clipboard was looking at the plane from atop a scaffold, with a shocked expression on his face. The guy standing next to him said something like, "Don't worry, this always happen when everybody works a lot of overtime..."

 

--Peter

Share this post


Link to post
Share on other sites
LOL. Fixing nonexistent problems may take some time apparently.

 

But putting problems into a lens which had none before - they can do in about 6 weeks.

 

I am now actually glad they returned my Elmarit-M 90 without coding it. I would rather have to touch up the hand-coding lines with a Sharpie every month or so than have an out of adjustment lens.

 

Wilson

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