Home
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

What did I get - CZJ 5cm Sonnar LTM?
View previous topic :: View next topic  


PostPosted: Sun Apr 23, 2017 11:13 am    Post subject: What did I get - CZJ 5cm Sonnar LTM? Reply with quote

Hi, I recently got this lens:



I'm guessing it's an early postwar lens? Made in Jena when it was under Russian control? Can anyone comment on that based on the serial number? I hope it is not a fake - seems somewhat different from J3-s, has small m on distance scale, matching stamped numbers on rear optical block, etc.

Seems it has had a rough life, rings are misaligned and some of the screws are not original. Aside from nice bubbles in the glass it seems to have a pretty obvious fungus problem Sad


(there's more of it than is visible in this image, pretty much all around the rear elements)

I guess I should have it serviced to see if it can be cleaned up and put together a little better. Any particular precautions? I understand it is likely to have soft coatings on the inner elements and that the front name ring has a set screw so it can't simply be unscrewed from the front without taking more things apart? The actual fungus seems to be towards the rear, though.


PostPosted: Sun Apr 23, 2017 11:47 am    Post subject: Reply with quote

Here are the serial numbers/years: http://camera-wiki.org/wiki/Carl_Zeiss_serial_numbers
Obviously it's a mid/end war production.


PostPosted: Sun Apr 23, 2017 11:59 am    Post subject: Re: What did I get - CZJ 5cm Sonnar LTM? Reply with quote

MartinV wrote:

...
I hope it is not a fake - seems somewhat different from J3-s, has small m on distance scale, matching stamped numbers on rear optical block, etc.


I'm not an expert on CZJ lenses, but due to the "m" and the matching stamped numbers i would say it's original.
I found my LTM 1.5/5cm Sonnar a few years ago here in Zurich; it was matched to a rangefnder Leica built in 1941. Here in Switzerland you can occasionaly find civilian CZJ wartime lenses which were already coated. Obviously they found their way into neutral Switzerland during these difficult times...

You can find an image of two civilan coated wartime Sonnars here on my website:
http://www.artaphot.ch/zeiss/objektive/203-sonnar-5cm-1-1-5

Stephan


PostPosted: Sun Apr 23, 2017 12:52 pm    Post subject: Reply with quote

According to Thiele's Fabrikationsbuch Carl Zeiss Jena, it was assembled in Decembre 1945.
my guess is, that it looks original.


PostPosted: Sun Apr 23, 2017 1:41 pm    Post subject: Reply with quote

Have a look here, Martin...http://www.klassik-cameras.de/Zeiss_Fakes.html


PostPosted: Sun Apr 23, 2017 3:44 pm    Post subject: Reply with quote

It's obviously not a fake, as many people could think.
According to the serial# it was made in 1941-1942 year, during WWII.
If you want to be 100% sure about It - last 7 digits of the serial number should be diplicated on the bottom of the lens block, like here:
https://goo.gl/photos/FqyZfTvQ3pecvSd66


PostPosted: Sun Apr 23, 2017 9:35 pm    Post subject: Reply with quote

I personally would not work on a lens of this value. I don't hesitate on cheap lenses but on these rare old beasts a wayward screwdriver or such can seriously devalue them. I would find a reputable lens technician. But then my lens repair skills are very weak (but improving). Just my opinion.


PostPosted: Sun Apr 23, 2017 11:05 pm    Post subject: Reply with quote

jamaeolus wrote:
I personally would not work on a lens of this value. I don't hesitate on cheap lenses but on these rare old beasts a wayward screwdriver or such can seriously devalue them. I would find a reputable lens technician. But then my lens repair skills are very weak (but improving). Just my opinion.


Like 1 small Like 1 small Like 1 small exactly, would do the same!!


PostPosted: Mon Apr 24, 2017 8:50 am    Post subject: Reply with quote

Thank you for your comments, everybody. I was hoping someone had access to the Thiele book. Does it indicate that the serial belongs to a batch of LTM Sonnars or just the production month?

I understand that this is a factory LTM lens, not a Contax optical block transplant? How did Zeiss end up making lenses in LTM, did it happen already before the war or did it begin during the war?

This is what I managed to find on the subject:
https://www.photo.net/discuss/threads/zeiss-sonnar-50mm-lens-in-ltm.147606/#post-1683840
EDIT: and this: http://leicaphilia.com/carl-zeiss-jena-sonnar-5cm-1-5-for-leica/

alex_KS, based on what I've read, 1945 seems more likely to me, but you say 1941-1942? How did you determine that? It does have the last six digits of the serial on the rear lens block, in the same style as in your image.

I have no intention of working on the lens myself, I'd take it to a local repair guy. I'm sure he's handled Jupiter 3-s etc before, so I'm just trying to figure out what differences I should warn him about, such as the set screws holding the name ring and I guess also the rear optical block?

I think it would be a good idea to have him clean out the fungus, or is that more likely to cause damage than do any good, because of the soft coatings? Also the focusing is very uneven and the lens doesn't seem to be put together quite right (the misaligned rings). Aperture is fine though and all the fungus seems to be behind the aperture.

Optically it seems OK, central area is pretty sharp wide-open.

Would you recommend for or against having it CLA-d?


PostPosted: Mon Apr 24, 2017 9:11 am    Post subject: Reply with quote

MartinV wrote:
...
I'm sure he's handled Jupiter 3-s etc before, so I'm just trying to figure out what differences I should warn him about, such as the set screws holding the name ring and I guess also the rear optical block?

I think it would be a good idea to have him clean out the fungus, or is that more likely to cause damage than do any good, because of the soft coatings?


I once opened a wartime coated Sonnar 1.5/5cm (Contax mount) - the inner coatings were extremely sensitive, just wiping the lens surfaces with a soft cloth was enough to destroy them! You have to be aware that removing the fungus might remove the coating as well. Your serial, however, is quite a bit higher than mine was, and maybe your coatings are already better than the ones on my lens. Or maybe not ...

Stephan


PostPosted: Mon Apr 24, 2017 1:01 pm    Post subject: Reply with quote

Here you can find the data about production year of Zeiss Jena lenses - http://forum.mflenses.com/carl-zeiss-jena-lenses-issue-date-by-serial-number-t6865.html


PostPosted: Tue Apr 25, 2017 9:01 am    Post subject: Reply with quote

Stephan and others - assuming it has soft coatings, would you leave the fungus in there to preserve whatever is left of the coatings? Personally I'm pretty paranoid about fungus and would really like to have it cleaned off if possible.


PostPosted: Tue Apr 25, 2017 9:28 am    Post subject: Reply with quote

You have to bear in mind that this lens is rather a collectors item and quality wise mediocre for today's standards. The majority of cheap modern standard lenses will blow it away in terms of picture quality in every aspect. I would not invest too much for restoration.


PostPosted: Tue Apr 25, 2017 10:48 am    Post subject: Reply with quote

Even bigger caution cleaning inner elements: using usual stuff like Isopropyl alcohol getting in touch with glued elements creates or enhances separation!


PostPosted: Wed Apr 26, 2017 2:53 am    Post subject: Reply with quote

First thing, expose fungus to UV light to kill fungus, the glass it's on is likely being etched as we speak, and cleaning that element I'll likely damage the coatings not covered by the fungus, hopefully the fungus is young and hasn't had much time to etch much, only one way to find out.
Good luck.


PostPosted: Wed Apr 26, 2017 5:52 pm    Post subject: Reply with quote

MartinV wrote:
Stephan and others - assuming it has soft coatings, would you leave the fungus in there to preserve whatever is left of the coatings? Personally I'm pretty paranoid about fungus and would really like to have it cleaned off if possible.


I myself - inadvertently - have cleaned away some haze (without fungus yet) and a part of the corresponding coating of that lens. This means that one of the six surfaces of the Sonnar now is partly uncoated. From a user's point of view this certainly is not a major catastrophy, especially since the Sonnar has been designed completely without coatings!

I certainly would clean the fungus, as carefully as possible and only the areas affected - this for sure will enhance image quality, but not to the point a fully and perfectly coated lens.

tb_a wrote:
You have to bear in mind that this lens is rather a collectors item and quality wise mediocre for today's standards. The majority of cheap modern standard lenses will blow it away in terms of picture quality in every aspect. I would not invest too much for restoration.


Yes and no. You know that i usually prefer "sharp" lenses. However, the Sonnar, used on my tiny NEX-5N as a tiny "vintage" portrait lens, has quite a few advantages. Cropping cuts away the most severe aberrations (at f1.5), the lens fits perfectly to the tiny NEX-5N, stopped down to f5.6 / f8 is is very good, and wide open its images look is really and nicely "vintage". I mean everyone can see it... Wink

Stephan


PostPosted: Thu Apr 27, 2017 5:44 am    Post subject: Reply with quote

stevemark wrote:
..., the Sonnar, used on my tiny NEX-5N as a tiny "vintage" portrait lens, has quite a few advantages. Cropping cuts away the most severe aberrations (at f1.5), the lens fits perfectly to the tiny NEX-5N, stopped down to f5.6 / f8 is is very good, and wide open its images look is really and nicely "vintage". I mean everyone can see it... Wink


Every Jupiter-3 would do the same "trick", most probably better when it's free of fungus. Wink


Last edited by tb_a on Thu Apr 27, 2017 12:34 pm; edited 1 time in total


PostPosted: Thu Apr 27, 2017 10:53 am    Post subject: Reply with quote

MartinV has both an uncommon and interesting lens and, unfortunately, something of a dilemma about how to proceed with it.

Without being unkind, as it stands it's a scruffy lens that's got fungus. has had a hard life, and - to make things still worse - been incompetetently taken apart and re-assembled. Removng the fungus will improve its imaging more than losing the coating on the same surface will degrade it, so that's the proverbial "no-brainer". If the rest of the interior surfaces are reasonably clean, then they're best left alone if the coating is indeed so delicate. Sorting out the mechanicals will make it nicer to use, so that's another bonus. If it can indeed be fully dismantled Sad

However, all this will be expensive if Martin sends it to one of "top class" people who do this sort of work. Sending it to anyone inexperienced in refurbishing old lenses could be a recipe for disaster. Will an overhaul be worthwhile? Economically speaking, almost certainly not - collectors like pristine and as original as possible, and this lens won't ever make "top money". Photographically speaking, perhaps - if Martin is prepared to spend money which he probably won't get back if he ever sells it. (Yes, Iknow . . . we all do that at times !)

If it were mine, I'd take photos with it first and see how it behaves under as wide a range of conditions as possible - it might just be pleasing as it stands. If the results are disappointing, then it will time to bite the bullet.


PostPosted: Sun Apr 30, 2017 12:34 pm    Post subject: Reply with quote

https://www.flickr.com/photos/90768661@N02/albums/72157647700164883

I suspect your lens was assembled after the war, "probably" using parts as found in the factory.

The SN puts it in the 285 block, these normally (but not always) have Black rims. The earlier 272 block lenses normally have chrome rings.

You don't show the entire focus ring: there should be a smaller screw under the screw that holds the ring in place. This serves as a limit screw for close/infinity focus. The Jupiter-3 mechanism uses an internal limit screw.

helical_numbers by fiftyonepointsix, on Flickr

retaining_screw_marked by fiftyonepointsix, on Flickr

Your lens: there might be hidden set screws holding the rear section in place and the name ring in place. You must unscrew the optics barrel from the mount and check for it before trying to unscrew the rear. Most of the Sonnars between 267 block and 285 block have this, most assembled after the war quit using it. 285: verify it.

It's best to remove the fungus, even if it means removing the coating on the surface. I've done this before, performance was improved.

This is from the album above, wide-open at F1.5 on the Leica M9:

Manassas Battlefield by fiftyonepointsix, on Flickr

Compared with the modern C-Sonnar, the latter is slightly better.

Compared with a Jupiter-3+, ZK Sonnar 5cm F1.5, and (very rare) Nikkor 5cm F1.5 in Leica mount.

https://www.leicaplace.com/threads/jupiter-3-plus-compared-with-three-rare-sonnar-lenses.1477/


PostPosted: Mon May 01, 2017 11:20 pm    Post subject: Reply with quote

This shot was taken with a lens originally in the same condition as yours, I removed the coating of the inner surface of the rear triplet.

riverboata by fiftyonepointsix, on Flickr

Taken almost 10 years ago, Kodacolor 400 in the Canon P. This particular Lens was sold off a long time ago.


PostPosted: Thu May 04, 2017 8:59 am    Post subject: Reply with quote

An update: took the lens to a local repair guy. Got it back after a day with the following comments:

1) the lens has probably been cleaned previously - the fungus-like patterns seem to be just traces, probably left behind on the coatings, glass itself was supposedly smooth.
2) he did not fancy taking the focusing mount apart because of the non-original screws, some of which seem to be epoxied into place. He wasn't sure he'd be able to get it back together again.

So I guess the lens will remain as-is for the foreseeable the future, as a survivor, an interesting historical item and an occasional shooter Smile

Thank you all for the information and guidance you provided!


PostPosted: Thu May 04, 2017 11:09 pm    Post subject: Reply with quote

The Chrome Nosed lens from the same batch as yours did not have the distance scale engraved on the focus ring. The RF disagreed with actual focus, and the helical was cemented into the mount. I had to polish down the RF Cam to make the lens usable. A friend of mine sent me these Five lenses to work on several years ago.



The other lens from the 285 black has the more common Black Rim- was easier to work on.

IF you want to get to the rear group: just use a spanner on the inner retaining ring. IF there is a hidden set screw holding the fixture in place, the retaining ring still comes out and you can pop out the triplet for cleaning.


PostPosted: Thu May 04, 2017 11:13 pm    Post subject: Reply with quote

These lenses were all "authentic"- when taking them apart a couple had the inner numbers for the parts of the focus mechanism.



The ZK Sonnars also can be found with these numbers.


PostPosted: Wed Mar 07, 2018 9:03 pm    Post subject: Reply with quote

Well, I found another one, but I think this one might be a fake or a hybrid:



It has "M" on the distance scale instead of "m". So maybe a Jupiter 3 focusing mount; but could it still be an original Sonnar optical block? A remounted Contax? I am unable to unscrew the optical block from the focusing mount, so I can't check for numbers on the rear block like I could with the previous one. Anybody able to tell me anything based on the pictures or the serial number?