Are ZM Lenses light tight?

Ok, problem solved on my 50 C-Sonnar, just put a little black silicone over the offending screw and no more problems even in direct sunlight. I'll post some example shots soon.

I also made an interesting discovery. Curious as to why my other two ZM's don't have this problem while my 25 and 50 do, I had a closer look at their flanges.

On my 18mm Distagon, it turns out I have the older bayonet which is not as easy to code, so that answers that one.
However, on my 35mm C-Biogon, which has the newer flange, it appears that the countersinking for the screws is MUCH more minimal than on the 50mm C-Sonnar. I think Zeiss know about the issue, or have a new QC issue they weren't aware of.

Oh just got an official statement from Zeiss, they will not be offering service or repairs of this issue as their lenses were designed for short exposures in the visible spectrum. They are also still stating that the M9 and it's IR Cut (technically an IR termination, not cut 😛) filter are leading to the problem. Someone should link them to this thread. In the meantime I'll fix the lenses I have which show the problem, and just not buy any future ZM's.

I understand for many this is a non-issue and I'm glad for them. *I* like to shoot IR, and often with ND's and other filters which modify exposure times, I like to have the option of interpreting the world in other ways without having to say "oh wait this lens doesn't work properly for those kind of shots". I know of architecture photographers who shoot very long exposures with ND filters to blur people out of shots as well. At the end of the day Zeiss have a slightly less versatile product which for most won't matter, but for me it really does, so I'll save for longer and look for the red dot on the next lens.
 
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thrice said:
Oh just got an official statement from Zeiss, they will not be offering service or repairs of this issue as their lenses were designed for short exposures in the visible spectrum.
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The lenses were DESIGNED to leak light? I call bullsh-t! 🙂

I bet there are some real world conditions that could create the problem.

Just to make up a scenario: imagine you're standing in the sunlight, but you're trying to photograph the entrance of a cave. The cave would be dark and you'd need a long exposure. However sunlight would be hitting the lens barrel. I bet you'd see the leak in that situation.
 
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They're just trying to avoid a mass panic I guess. What if every ZM owner shooting on an M8/9 wanted to send back their lenses for "repair". Even film shooters who might want to resell their lenses might take exception.

Head-in-the-sand is an approach I usually associate with the likes of Toyota and Panasonic who like to say "our products have no problems" when numerous end-users have uncontrollable acceleration or rapidly worsening black levels in the case of Panny's 12G plasmas. I tend to expect more of German manufacturers, but in this day and age I guess no one is exempt from arrogance.

Your example of the cave shoot is a very good one. I still think whoever is doing the PR for Zeiss is unaware of the exact cause and ramifications of the problem. I made the mistake of mentioning IR when I first contacted Tony Rose, who then forwarded my e-mail to Zeiss for me. Of course they're gesticulating around that point as much as they can saying that the lenses aren't designed for IR as it's an easy way out.
 
I don't think that the right person at Zeiss has looked at this issue yet. If I were you I would continue to pursue this directly with Zeiss. You could send an email to photo@zeiss.de and see if that somehow gets to someone else who could look into this.

I did send an email to Tony at Popflash but all he can do is pass on the "answer" from Zeiss in New York, so I got the same response you did. I might try calling them tomorrow to see if this is the best they can do.

Even if I haven't encountered this problem in my own photography yet, I'd prefer to have lenses that don't leak. Who knows, I might try shooting landscapes with an ND filter one day. I also want my lenses to keep their second hand value if I ever wanted to sell them.

It just seems that a company that promotes their lenses with the following:

"The Carl Zeiss range of T* ZM-mount lenses offers the highest possible standards in terms of performance, reliability and, of course, image quality. Quite simply, they are superior in every way."

could do a lot better in handling this problem.

-Thomas
 
Double Negative said:
I've had good luck with Richard responding to emails:

Richard Schleuning
National Sales Manager, International Sales Americas
PO Box 112, Roseland, NJ 07068 USA
Phone: 973.226.7387
rschleuning@zeiss.com
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The first response Tony Rose from Popflash forwarded to me, was from Richard Schleuning. I was a little surprised as Richard seemed very insightful in the Zeiss Cine Lens interviews I watched. I guess he didn't want to admit there could be a compatibility issue with 25 and 50/1.5 ZM's and M8/M9.

Granted we hadn't yet determined the exact cause of the problem and any good product manager won't criticise their own product. I may link him to this thread.
 
Mr Schleuning has informed me that he has forwarded the information I sent him (including the url of this thread) to the Zeiss factory as they are more qualified to respond. Fair enough, hopefully someone will chime in or send me an e-mail of sorts 🙂
 
Ok everyone time for an update!

No contact from the Zeiss factory, but that was expected, I assume they're hoping the discovery of this design flaw just goes away.

Tony Rose at Popflash.com replaced my lens (even though I let him know he didn't have to) which was very kind of him! I received the replacement lens today.

Unfortunately the problem is not resolved, in fact it is much worse on the new lens! This is still with an ND filter, but taken at f/16 at 0.7s! That's a very short exposure and a result that could easily occur in real world environments. The leak is so intense that it caused the camera to meter the scene as a lot brighter than the light coming through the lens. This is as shot, -2/3 exposure comp, no processing. Look at that flare!

25mmFLARE.jpg


Suffice to say I'm currently waiting for the Silicone to set on the lens and will re-post when that is finished.
 
What Zeiss will want to do is to take some of their lenses and try to repeat the circumstance that you're seeing.

Once you can reproduce a flaw then you can go about correcting it.

I'm sure it's not their intent to make a product that doesn't work correctly with the M9, and it serves no purpose to offer a knee-jerk reaction until they have a chance to check it on their own.

Is your case an isolated incident? We'll know soon enough. Hopefully.

This isn't a safety issue. People don't die because you are getting a light leak from a camera. Of the 320 million people in the U.S., 3.19999 million don't care. Aggravating? No doubt. Deadly flaw? Not hardly. Coverup? Let's stop the conspiracy theories.
 
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Benjamin said:
Read the rest of the thread Sir. 😉
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Lol I was about to post the same thing. Or read the thread on GetDPI.

Mike, do you have some ZM's and an M9 you could test as well for us?

My "kneejerk" reaction is a result of Zeiss saying I'm shooting under unnatural circumstances and that their lenses are not designed for IR or long exposures. So perfectly valid IMO. They also tried to blame my M9 saying it has a light leak in it.
 
ZeissFan said:
This isn't a safety issue. People don't die because you are getting a light leak from a camera. Of the 320 million people in the U.S., 3.19999 million don't care. Aggravating? No doubt. Deadly flaw? Not hardly. Coverup? Let's stop the conspiracy theories.
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Holy crap 316800010 americans care about the problems an Australian is having with his German designed lens, which is manufactured in Japan? Seems like an awfully large number. Perhaps you meant 319.999999 million?
In which case, this Australian still doesn't care what any americans think of his problems with his German designed lens that is made in Japan 🙄 I was just trying to inform others of a potential problem.

If it's not a big deal, no need for you to stop in and post in the thread. If it's not a big deal then it's not going to harm Zeiss, they will either provide a solution or we'll see one person do a test shoot outdoors with an M9 in direct sunlight with one of these lenses and an ND filter and post that they have no problems and I'll know it's a tolerance issue with my M9. My M9 which has no issues with any other lens except 2 out of 4 ZM's I own, neither of my 2 Leica lenses and neither of my 2 Voigtlander lenses.
 
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Hey Mike, I was referring to ZeissFan, but you're just as good - and some might argue more impartial 😛 - a tester 🙂

I can't wait to test the lens tomorrow when the silicone has set. It really did the trick with my 50 C-Sonnar, so I'm hoping it solves my Biogon woes and I can go on about my business and shoot with little stress in the New Zealand wilderness. Of course I would prefer Zeiss sent me a pair of replacement modified/fixed bayonets for my offending ZM's but that isn't going to happen easily.
 
The silicone on my 25mm Biogon has set.

25mmFLARE-2.jpg


Note these have only been 0.7s exposures (this and the previous severe leak one). Totally reasonable for shooting waterfalls and other water features during daylight IMO, a very "real-world" scenario.

I know for a fact now Zeiss are aware of the issue and have some very esteemed and high up scientists fully investigating the issue, which is good news.

Here is a scenario where I had to use an ND1.8 (same as above) to get some fluidity in the water movement just the other day:
LesmurdieL1001272_CF.jpg


Sorry about the weak waterfall, low water levels following a hot summer in Western Australia.
 
trisberg said:
it happens to be opposite this screw on the mount on the camera body:
bodyscrew.jpg
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Note that Leica has deliberately changed the position of this screw with the introduction of the M8. See how it looks on the M6, which is the same on all other Ms before the M8:

leica-M6blk-F.jpg


With that kind of arrangement it should work fine; with the redesigned M8 mount you get the screw arrangement that leads to the light leak you describe.

Makes you wonder why they put the screw on the camera right where it is. They probably had a good engineering reason to do so, with the added side effect that Leica lens competitor Zeiss now has a PR problem and likely has to change the bayonet on all their lenses.
 
Fuwen, what do you mean by cut out position? None of your lenses have a groove for coding?

rxmd, you're quite right, there really is no reason that I can think of to rearrange the screws, except for the fact that one of the screws on the old bayonet would interfere with where the coding reader is.
 
trisberg said:
The screw that causes the problem is the one where the cutout for the focus following arm is.

Here is the screw on the lens (covered with a small piece of gaffers tape):
lensscrew.jpg


i
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I mean none of my ZM lenses have the screw shown above, as all of them are the older batch. I dun use digital.
 
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