Strangely repaired/modded Sonnar 50mm 1,5?

simonOWO

simonOWO

Member
Local time
9:06 PM
Joined
Nov 24, 2024
Messages
48
Location
Hangzhou
View My Gallery
I recently found and bought this Sonnar from eBay, which I believe is v5b ZO CR bz. After receiving it, I had difficulty mounting it to my Amedeo adapter. While researching the issue, I came across this amazing place 😀

The problem seems to be the "position claw" (painted in red), which is unlike any other Sonnar I have seen online. The claw has a "sloped base" that interferes with the adapter's tight tolerances.

IMG_4864.jpeg

Upon closer inspection, I noticed a few other unusual things:
• The brass around the claw is fully exposed, and the red paint is messy.
• The claw is bent on one side.
• The flat-head screws was sanded?

IMG_4862.jpegIMG_4865.jpegIMG_4860.jpeg

I suspect this lens was poorly serviced, as I can see cleaning scratches on almost every element. I haven’t tried on camera yet, but it seems like it will focus.

IMG_4866.jpeg

I was thinking of grinding the slope on the claw to make it closer to a right angle so it fits the adapter. What do you recommend? Should I modify the adapter instead?



Picture with serial number:

IMG_4861.jpeg
 
It looks like the original latch broke off, which is common. I've seen the Tomosey repair manuals show how to make one similar to what you are showing. I've transplanted one to a Nikon S-Mount from a spare Jupiter mount. It works, but don't force it too hard. Probably best to gently file the tip of the latch to fit into the adapter, and leave it there.
I dedicated an older adapter to the S-Mount lens that I repaired.
 
I have had a similar one with a very similarly crudely finished latch. The mount was roughly finished as well. Also the eccentric screw that determines the aperture scale fine adjustment was very crude in fit and finish. The serial number was 1.88million something - so quite late into the term.

Initially I assumed it may have been some prototype or something that was quickly thrown together, but I guess it may also just have been inexpert repair.
 
Sonnar Brian said:
It looks like the original latch broke off, which is common. I've seen the Tomosey repair manuals show how to make one similar to what you are showing. I've transplanted one to a Nikon S-Mount from a spare Jupiter mount. It works, but don't force it too hard. Probably best to gently file the tip of the latch to fit into the adapter, and leave it there.
I dedicated an older adapter to the S-Mount lens that I repaired.
Click to expand...
Thanks for the reply, I would file it carefully
 
TenEleven said:
I have had a similar one with a very similarly crudely finished latch. The mount was roughly finished as well. Also the eccentric screw that determines the aperture scale fine adjustment was very crude in fit and finish. The serial number was 1.88million something - so quite late into the term.

Initially I assumed it may have been some prototype or something that was quickly thrown together, but I guess it may also just have been inexpert repair.
Click to expand...
Maybe ours are from the same repair shop 😀
 
Excellent! Looks good, and works even better.
The Amedeo Adapter is uncommon, and worth more than the lens. Modifying the lens, and keeping the adapter all original lets you use it with many lenses.

If you come across another Sonnar with bad glass, you can always transplant the barrel to another mount. I've done that.
 
Sonnar Brian said:
Excellent! Looks good, and works even better.
The Amedeo Adapter is uncommon, and worth more than the lens. Modifying the lens, and keeping the adapter all original lets you use it with many lenses.

If you come across another Sonnar with bad glass, you can always transplant the barrel to another mount. I've done that.
Click to expand...

I think I kinda need to modify this lens. Tried on camera today, with the Amedeo adapter the rangefinder coupling wasn’t accurate.

As this is my only lens and adapter, I can’t tell which of one is causing the inaccuracy. The camera is accurate and was checked with other leica lenses.


The problem is that the lens focuses closer than what the rangefinder indicates. This suggests the lens sits farther from the sensor than it should.

If I want to adjust this, what is the correct way? From what I have read online, removing the outer rear retaining ring should allow the barrel to come off. But the barrel itself is not threaded.

I assume I need to set the lens deeper in the barrel, so the elements would be closer to the film/sensor. Is this possible with this kind of Sonnar?

May I ask is there anything else I should know and be cautious about?
 
This is a very easy lens to correct the focus. It is sitting out too far from the image plane. You need to use a "spanner" to take the retaining ring off from the back of the lens. The Barrel drops out. Be careful of the Guide Screw that is seen from the side of the lens, it can fall out. I hold it in the down position while removing the barrel.

www.ebay.com

Stainless Steel Spanner Wrench Set For All Camera Lens Opening Repair Tools | eBay

Made of quality anti-magnetic stainless steel, nice looking and durable. Product View.
www.ebay.com

Once out, there is a variable stand-off ring. Screw it about 1/2 turn towards the front of the lens to correct a front-focus of ~2" at 3ft. Screwing the ring clock-wise moved it towards the front the the barrel, allowing it to sit farther back when in the mount.
 
TenEleven said:
I don't have anything useful to add here really, perhaps that I wish that more companies adapted the late Carl Zeiss variable standoff system (all their later lenses have it). It saves so much hassle having to find or make shims and then find them either too thick or too thin. Disassemble again, etc etc
Click to expand...
Very true, such a simple system. I hate fabricating shims.
 
Update if anyone interested:
adjusted with leica store‘s M11, they are very kind to let me use it for the adjustment.

It’s nearly perfect for me, now focus well on both infinity and ~0.7m with the adapter.

In case anyone have the same issue and found here, this ring is what you will turn, on my particular lens the ring was very loose and can be easily adjusted by hand

IMG_4964.jpeg
 
The thread is 0.5mm per turn, times 0.3: makes it 0.15mm. That is more than enough to be noticeable.

This adjustment is about what you would need to use a Zeiss lens on a Nikon Rangefinder. Maybe someone adjusted it for a Nikon. Put it back on a Contax, or adapter made for Zeiss lenses: it would close-focus by what you are seeing. I've adjusted Zeiss Sonnars for my Nikons, and a Nikon S2 custom-shimmed for Zeiss lenses.
 
Oh! Make sense! You are detective!

I just happen to have a different question, which you might help me:

The lens consists of 3 groups: 2 groups - aperture - 1 group - camera

I can disassemble and take out the last group to clean the inside, but for the space between first 2 groups, I have some difficulty: I don’t know what is the correct way to take out the first group.

My version have two rings I can unscrew from the front, inner ring with the name and outer ring on which the name ring is mounted to. (Different from the Mike elek guide)

I tried turning outer ring but it takes a lot of turns, I also hear something strange, so I stopped to avoid any possible damage to the lens.


And do you have any recommendations on type of grease, or if grease is necessary, for the aperture mechanism?

Thanks!
 
Last edited:
The lens is a "1-3-3", front element, front triplet, aperture, and rear triplet.
There are two distinct versions of the barrel, and they seem to run concurrently in production.
The one you have: the front section comes out as a block from the main barrel.
The retaining ring comes off that block. You need to hold the block with a rubber grip, and remove using the spanner. Sometimes paint/dirt/grime makes the front ring very difficult to get off. You could try a little isopropyl alcohol around the threads. Sometimes- the threads are damaged, and very difficult to remove. If it is that difficult, unless there is a lot of haze or fungus- best to leave alone. The outer ring does require many turns. Sometimes it can squeek and scrape as it comes off. Unless a high amount of force is required for the final few turns, is probably Okay. I've run into that.

Big Bertha the Spanner.
RIMG0024.jpg

On some of the wartime Sonnars, earlier than yours- a set screw hidden under the aperture ring is used to hold the ring in place. Just in case you ever come across one.

Do not use any grease for the aperture mechanism.
 
Thank you for your guide, I successfully completed the cleaning of the front element, although caused a scratch on the naming ring due to lack of experience 😅

I also got a early Opton Sonnar, the heavy one with a different design, it also needs a bit of cleaning, some fog on the first element and second element/group as I can see.

But the thing that bugs me is the aperture ring being too stiff, I wonder if there is a good way to disassemble and fix it? I haven’t open it yet so I don’t know what is causing it, (I have read on this forum that it might be the variable standoff ring wrongly screwed to the end, as with the case of a incorrect repair)

IMG_5011.jpeg
 
And the edge of the elements seems to be very reflective, zeiss didn’t apply black paint?

I wonder if apply black paint on the edge of elements will the reduce reflection and improve contrast 😆
 
A word of warning: If you decide apply black paint. You should absolutely use water soluble paint -- or you will be very sorry when the solvent within the paint wicks into the balsam holding the lens groups together.

I found that calligraphy ink or something similar works quite well. Since there is no physical stress on the elements after you've put them back I had no issues with it flaking or rubbing off over the years.

That all said, I found the blacking to be more of a cosmetic issue (it is indeed unsightly) than anything that affected the imaging quality of my lenses. Even in very bad cases.
 
You must log in or register to reply here.
Back
Top Bottom