Are ZM Lenses light tight?

Mister E said:
Dan, you're right that's not very long, but companies have been making m-mount lenses for 50 years without issue. I wonder if this is a ZM only issue or if it is an issue with other cosina lenses. I've had the ZM 18, 21/4.5, 25/2.8, 28/2.8 and 50/2. The 21/4.5 was the only one where I saw any issues.
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Nate,

I see that you aren't going to wait for a solution from Zeiss and have moved on from Zeiss products, or at least the lenses. Funnily, I was just about to pick up a set of Zeiss lenses, pretty much similar to the focal lengths you have above except I'll replace the 50 with a 35. I suppose now I'll have to reconsider.

I wonder if Voigtlander lenses have the same problems. Perhaps somebody can compare the lens mount with the Zeiss ones if they have access to both lens mounts.

Cheers,

p.s. Many thanks for the great detective work and trouble shooting from Daniel (thrice) and Thomas (trisberg)! Well done!
 
bennyng said:
Nate,

I see that you aren't going to wait for a solution from Zeiss and have moved on from Zeiss products, or at least the lenses. Funnily, I was just about to pick up a set of Zeiss lenses, pretty much similar to the focal lengths you have above except I'll replace the 50 with a 35. I suppose now I'll have to reconsider.

I wonder if Voigtlander lenses have the same problems. Perhaps somebody can compare the lens mount with the Zeiss ones if they have access to both lens mounts.

Cheers,

p.s. Many thanks for the great detective work and trouble shooting from Daniel (thrice) and Thomas (trisberg)! Well done!
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I just moved on from having to many lenses. I have now only the ZM 18/4, 35/1.4 ASPH and 50/1.4 Lux. I have never seen any light leaks on my CV lenses. I also still have two Ikons which are great.
 
I haven't had any problems with this yet on the two ZM lenses I've owned (21/4.5 and 35/2). I have a M's though and it doesn't look the like the screw holes on the mount and on the lens line up. At least on the 21 - I no longer have the 35.

I'll keep an eye out for it though.
 
The best ZM lenses are so good and generally such terrific values that I have no problem with applying a dab of black silicone to a single screw hole as necessary. It won't harm the lens. It apparently solves the problem where it does occur, and it's pretty clear that the problem is minor-to-nonexistent except in rather specific applications, anyway.

Many thanks to those who discovered and isolated the issue.
 
Mister E said:
There is nothing specific about my application of the lens and it's light leaks.
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It seems to occur with specific combinations of camera bodies and lenses. It seems to occur specifically with long exposures. It seems to be worse with specific lenses and specific samples of lenses.

Most users of ZM lenses have not encountered these difficulties in their photographic applications. I might even say that generally, this has not been a problem.

Perhaps you and I have different specific definitions of the word "specific"? 😱

Again, thanks to you and the others who have identified and isolated this issue.
 
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Double Negative said:
FWIW, even Nikon is not immune.

[URL="http://www.robgalbraith.com/bins/content_page.asp?cid=7-10053-10796"]24-70 light leak "not a problem with normal shooting" says Nikon USA[/url]
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This has been mentioned before in this thread. It's funny that the 24-70/2.8 has been out for years and people just found the light leak. I also think it's incomparable to say the complexity of a 24-70/2.8 AF-S f-mount lens is in the same league as m-mount. M-mount lenses have been around since the 50's and couldn't be simpler to make. No aperture coupling, no af, etc. Oh and Nikon is doing something about the problem. As of yet I've not heard anything from Zeiss.
 
trisberg said:
Well, they did change the location of the screws some time ago and also introduced a shallow groove around the mount. This groove makes it easier for people to hand code the lenses but it also reduces the surface of the mount. It seems that the newer mounts are the ones having this problem. I think people with older lenses simply don't have the problem.

-Thomas
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None of the ZM lenses I've used had the thinner mount.
 
So, what's the verdict? Does the mount type make any difference?

I just picked up a ZM 21/4.5 with the older non-grooved mount that brings up the 50mm frame, and am wondering if it will leak light....?
 
Shouldn't leak light. For what it's worth Zeiss have not contacted me and seem content that people will forget about this issue.

All people who don't want to EVER do long-ish exposures or use ND filters that is.
 


Pentax LX + Carl Zeiss Distagon T* 2/28 + Kodak Kodachrome 64

Hood on, hand held speed, and if you look on the slide, it is a straight line.
Not sure what is going on here. My ZK never flared like this, if this is a flare....
 
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