Is this a genuine Zeiss Sonnar LTM?

[mellie]

Is this a genuine Zeiss Jena 50mmf1.5 Sonnar in LTM? Thanks in advance for your input.:)
http://farm4.static.flickr.com/3422/3945632533_a735a75766_o.jpg
http://farm3.static.flickr.com/2555/3946415166_fcaeb46b38_o.jpg
http://farm3.static.flickr.com/2596/3946415248_6824983596_o.jpg

[Brian]

It looks real from all angles shown. Has all the features of a wartime Sonnar, and the Sn is in range.

Can you post a shot of the back of the lens?
I've seen some post-war Russian assembled lenses that had some custom machining in them. Usually a shiny aluminum finish and a smaller diameter rear fixture is a sign of completed in Russia.

It is very difficult to "confirm" it without taking it apart, such as is done when clean/luve/adjusting the lens, but I would certainly go after it.

[mellie]

Thanks Brian. I do not have a picture of the back of the lens. The barrel seems very "dirty". Can it be restored? Thanks again for your input.

[mellie]

How about this one, Brian? The lettering on the front seems different-smaller & more widely spaced.
http://farm3.static.flickr.com/2617/3949087184_42fa65f488_o.jpg
http://farm3.static.flickr.com/2632/3949087120_9d30c7b8e8_o.jpg
http://farm4.static.flickr.com/3500/3948305225_c01da36bc7_o.jpg

[Brian]

The rear of that lens is what I am talking about: I have seen several like it. I do not think it is an original Wartime CZJ 5cm f1.5, but was a "transition" lens or some custom job. I have seen several like it before, just worked on one this weekend.

See here for two like it:

http://ziforums.com/showthread.php?t=224

I've seen custom conversion jobs with the Name of the company on the mount. These have no indication of who made the mount, and do not have the Zeiss internal serial numbers.

But the only way to know is to take them apart.

[mellie]

The rear of that lens is what I am talking about: I have seen several like it. I do not think it is an original Wartime CZJ 5cm f1.5, but was a "transition" lens or some custom job. I have seen several like it before, just worked on one this weekend.

See here for two like it:

http://ziforums.com/showthread.php?t=224

I've seen custom conversion jobs with the Name of the company on the mount. These have no indication of who made the mount, and do not have the Zeiss internal serial numbers.

But the only way to know is to take them apart.

Which of the 2 lenses that I've posted are you referring to when you said you do not think it's an original Wartime CZJ? The second one? Thanks.

[Brian]

The second one does not look like an original wartime Sonnar. The RF cam and rear retaining ring are different from the three that I have taken apart. It is also different from the ZK Sonnar that I have. It looks closer to some other lenses I've worked on, all with various small differences.

[Brian]

Thanks Brian. I do not have a picture of the back of the lens. The barrel seems very "dirty". Can it be restored? Thanks again for your input.

I;ve used an ultrasonic cleaner and silver polish to clean up these aluminum barrels. It works. Sometimes the fine paint in the DOF scales does not survive. I've filled that in with marker. I'm not a perfectionist for cosmetics, want a decent looking lens with great performance.

This one was "really ugly" when received.

http://ziforums.com/showthread.php?t=143

But it looks pretty good now.

[mellie]

Thanks Brian for all your inputs. Here are some photos taken with the lens.
Taken with M8 at f1.5. Focus is spot-on. Mighty sharp & nice bokeh too!:). A Winner!
http://farm3.static.flickr.com/2556/3989113094_2cd9a21440_b.jpg
http://farm3.static.flickr.com/2601/3988392949_ee68f29d24_b.jpg

[Brian]

It looks really good!

I think you have a real winner of a lens. I love Sonnars.

[mellie]

Thanks, Brian. I love Sonnars too.
It looks really good!

I think you have a real winner of a lens. I love Sonnars.

[wilson.c]

The lens certainly looks good and original. One way to be absolutely sure is to remove the optical group from the helicoid (twisting apart the front and rear). Be careful, there are some shims that allow for infinity focus, don't loose these. At the base of the optical group, I think the last 6 digits of the serial number should be stamped on the ring. This should be the same number on the front lens ring.

Unfortunately the Sonnar that I got had a Soviet made M39 helicoid ('M' instead of 'm' on the focus distance scale, Large red triangle on the depth of field scale). When I took apart the optical group, there were some numbers scratched into the of the module (Soviet made again). Seems like someone just changed the front ring (the serial number is in the proper range of a batch of 5000 in unspecified mounts completed in late 1945) on the lens to pass it off as the real thing.

I'm still hoping that the glass is actually Zeiss from Germany as during the time, Soviet overseers required training of their staff to make proper mounts. Staff were given lens elements which I presume would be from CZJ to teach them how to properly make mounts. That is my hope anyway. The coating looks like the T coating of the day. I have to compare it to similar vintage of lenses to see if the reflections are similar.

[Brian]

The KMZ J-3's lenses all used German glass, raw stock on the later ones and cut optics on the early ones. I suspect 1951~1952 was the cut-off point for German cut optics. My 1956 KMZ has German glass in it, and performs identically to my 272 series Sonnar. I'm convinced that the 1956 switch-over to ZOMZ was also the cut-over to Russian glass and reformulated optics.

Can you post some shots of the lens?

[wilson.c]

Brian,

Here are some shots of the lens.

[Brian]

I have one within a few numbers of this one- and I believe it was finished after the war with German parts. The one I have had issues, including the middle group being uncoated and unfinished. I replaced it with an original from a parts lens. It is a fine performer, "now".

I suspect these were the learning curve of making the lsnes in Russia, out of parts carried back from Germany. I traded one of my 5cm F1.5 uncoated Sonnar conversions for mine.

[wilson.c]

Brian,

Thanks! That's what some of my Zeiss gurus were saying as well. BTW what's the color of the German made lens coating? You can't see it from the photos but it's a bit pinkish in the front and more purple in the rear.

[Brian]

The color of all the coatings is Blue-Purple. The early J-3's are close in tint.

[ray*j*gun]

Its a beauty... I am also a Sonnar fan!

[Brian]

I just spent a week on vacation in Georgia, took 500~600 pictures with the M8. 80% of them were with the uncoated CZJ 5cm F1.5 Sonnar. It is an amazing lens.