The 5cm F1.5 Sonnar-Jupiter Evolution

Sonnar Brian

Sonnar Brian

Product of the Fifties
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Over the Winter I will be putting together another "white-paper" on Sonnar and Jupiter 5cm F1.5 lenses. I've accumulated a lot of pictures from doing CLA, conversions, and repairs in the past. I've documented some of that work- Skyllaney in the UK now offers a service to convert Sonnars to Leica mount and to convert Jupiters for optimal use on the Leica. This involves changing the focal length to the Leica standard and then setting the shim. A real machine shop is required to get things just right.

I've "cherry-picked" 20 lenses that show the evolution of the 5cm F1.5 Sonnar through to the Jupiter-3+. I've made "mental notes" of some of the changes that took place, and made lots of photographs so I could get lenses back together.

I'll post some pictures in this thread as I get things together for the paper. These will be my working notes. Also- a good place to ask questions.

I'll start off with pictures of the Barrels and rear fixture. The optics of the KMZ Jupiter-3 and pre-war Carl Zeiss Jena 5cm F1.5 are compatible with each other. The rear fixture is the same shape between the KMZ and CZJ lenses. I've used parts of one to repair the other. The shape of the rear triplet and fixture changed when production moved to ZOMZ in 1956. Around 1963, no more removable rear fixture- the rear triplet is held in place in the one-piece barrel by a retaining ring. This design continues through to the Jupiter-3+.

 


Three Barrels of Jupiter-3, ZOMZ two-piece, KMZ, ZOMZ One-Piece
KMZ is taken apart, rear fixture in background.


Later two-piece, note threads up front and the guide ring for improved alignment in the barrel.


KMZ with rear fixture out. This can be used in a CZJ 5cm F1.5 Sonnar, and vice-versa.
Most KMZ J-3's made through 1953 have uncoated rear triplets. My opinion is that they are original Zeiss optics used after the war. Later rear triplets in 1954~1956 KMZ J-3's are coated, I believe most are Russian made. After buying more KMZ J-3s, I've found production of v1 and v2 KMZ J-3's was concurrent through early 1956.
 
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1934 5cm F1.5 Sonnar, rear fixture in background. This is the first batch that can be converted to LTM using a J-3 focus mount. The rear fixture is the same as the KMZ lens. This lens has all optics held in place by retaining rings, not stamped in as earlier lenses that I've seen. This lens was like wax paper when I got it for $67...




A close-up of the rear triplet from a 1937 Sonnar, note the serial number stamped into the fixture.

I have a ZK Sonnar and two 1950 Jupiter-3's with Zeiss serial numbers stamped into the rear fixture. Uncoated rear triplets on all three.
The rear fixture is interchangeable with the J-3. I've made hybrid Sonnar/J-3 lenses out of left over parts from basket-case lenses.
 

Ever wonder where the oil comes from that gets on aperture blades?
80+ year old grease to dampen the movement of the aperture ring.



It does clean off. Doing a CLA and Converting one of these lenses is labor intensive.



Taking apart an 80+ year old lens can result in destroying retaining rings, and even breaking the glass. The retaining ring for the middle triplet of the J-3 is interchangeable with the Sonnar. I know...
 
Let vandalizing of old good J-3 lenses begin. In addition to been depicted as fake Sonnars, they are declared as spare parts now... $%^&.

I modified my J-3 for use on M, I think, I used Brian Sweeney document. No machinery tools were needed. Lens is focusing on one meter just as good as on infinity. Can't notice focus shifts even on digital M. It is most compact and affordable 50 1.5 RF lens.
 
Ko.Fe. said:
Let vandalizing of old good J-3 lenses begin. In addition to been depicted as fake Sonnars, they are declared as spare parts now... $%^&.

I modified my J-3 for use on M, I think, I used Brian Sweeney document. No machinery tools were needed. Lens is focusing on one meter just as good as on infinity. Can't notice focus shifts even on digital M. It is most compact and affordable 50 1.5 RF lens.
Click to expand...

Of course I used the Rear Triplet from a Sonnar to repair my 1953 KMZ J-3... The Sonnar 5cm F1.5: Bought for $50, missing the middle triplet, and had the incorrect focal length front element. But the rear triplet and barrel- two lenses back to life.

I have a box of spare part J-3, J-8, and Sonnars. I used to convert the Sonnars to LTM for people, I charged $25 and Left-Over parts. They provided the two lenses. I got a lot of shims and an inventory of spare parts that way. Enough to note the changes that went into the lenses. I made one hybrid 5cm F1.5 Sonnar with very smooth Bokeh by trading optics, testing the lens, and keep trading until it was "perfect". Front element, middle triplet, and rear triplet from different lenses. If the J-3 optics were good, I converted them to Contax or Nikon. Gave some away, sold others for $75 and less.

When I do a thread on the F2 Sonnar, already have a title.

"Sonnar of '32" the story of a fast young lens and an affair with an older lens, Tessar.
 
Eight is Enough by fiftyonepointsix, on Flickr

1934 Carl Zeiss Jena 5cm F1.5 Sonnar on the M9, perhaps the first batch that can be converted to Leica mount using a J-3 focus mount.
1935 Carl Zeiss Jena 5cm F1.5 Sonnar, front element is Coated- first Sonnar that I converted to Leica Mount.
1936 Carl Zeiss Jena 5cm F1.5 Sonnar, uncoated- very sharp same batch as the one next to it.
1936 Carl Zeiss Jena 5cm F1.5 Sonnar, all surfaces are coated- a few lenses from this batch were pulled to try out the new coating equipment.
1938 Carl Zeiss Jena 5cm F1.5 Sonnar T, fully coated and marked with "T" for transparent
I converted these five lenses to Leica Mount.

These three are original Leica Thread Mount.
1943 Carl Zeiss Jena 5cm F1.5 Sonnar "T", recomputed optics, new metal alloy fixtures, original Leica Thread Mount.
1945 Carl Zeiss Jena 5cm F1.5 Sonnar "T" on the Canon 7, note "black nose" for filter ring, original Leica Thread Mount.
1946 Carl Zeiss Jena 5cm F1.5 Spnnar "T", post-war lens, "transition lens" as I call it. I needed to replace the middle triplet on this one, the original was unfinished.

All of these required a complete teardown and a lot of time spent cleaning, lubing, and adjusting. They are cherry-picked from more than 50 Sonnar 5cm F1,5s that I've gone through.

I'll get a family photo of my Twelve J-3's, 1949 ZK 5cm F1.5 through to the pair of Jupiter-3+ lenses.
 
Great work, Brian !

Thank you for sharing your expertise on the 5cm Sonnar lens and its derivatives .
 
The Sonnar 5cm F1.5 and Jupiter-3 are both nominal 52.4mm.



Looking at one of the datasheets I found online, there is a +/- 1% deviation. That means actual focal length can run from 51.9mm to 52.9mm. Those on the short end- will have no problem focusing across full range used wide-open after being shimmed. Lenses in the center- shim for close-up/wide-open, stop down a little for distance. The Sonnar focus shift due to spherical aberration is towards infinity. Lenses on the long end of deviation- stop down past F4, or change the focal length. That is done by bringing the rear triplet in closer.

From my instructions for adapting the Sonnar and Jupiter for use on the Leica. Formula for focal length and the "len's makers formula" .





This step- you can get some of the distance using sand paper and polishing barrel and fixture for the rear triplet down. BUT- to do this step correctly, a machine shop and measurements are required. This is the step that Skyllaney is taking for converting lenses.
 
First and the Last, KMZ Jupiter-3's.



The 1950 J-3 is a Carl Zeiss Jena 5cm F1.5 with SN showing it was made in May 1945.



The barrel is the same alloy as the wartime Sonnars. Later KMZ and other Jupiter-3's are all aluminum.

I increased the focal length by backing out the rear triplet.



Placed into a J-3 LTM mount from a badly damaged J-3.



This lens matches the wartime CZJ 5cm F1.5 Sonnar "T".

L1000047 by fiftyonepointsix, on Flickr

The earlier J-3's ARE CZJ 5cm F1.5 Wartime Sonnars. The J-3 LTM mount is a better design than the Zeiss mounts.

Perfect Glass. The focal length was wrong- was way too short for a Contax, it was unusable.



And it was held in the Contax mount using Sewing Thread. I think it was literally assembly practice.
I mark the original mounts of my unusual converted lenses, the conversion is reversible- have to keep the shims with the mount. This case- I could use this lens on a Nikon.
 
Jason Howe hosts PDF files of instructions I wrote a few years ago:

https://jasonhowe.blog/50mm-jupiter-3-f1-5-information

My advice is to test it on your camera up close at 1meter and wide-open. Use a ruler or measuring tape, mark the point of focus. Report back- if the shim needs to be changed, knowing the error at 1meter can easily be converted to change in the shim.
 
Sonnar Brian said:
Jason Howe hosts PDF files of instructions I wrote a few years ago:

https://jasonhowe.blog/50mm-jupiter-3-f1-5-information

My advice is to test it on your camera up close at 1meter and wide-open. Use a ruler or measuring tape, mark the point of focus. Report back- if the shim needs to be changed, knowing the error at 1meter can easily be converted to change in the shim.
Click to expand...

Thanks, Brian. I'll definitely check out the pdf. I actually tested the lens Sunday with targets at 1m, 2m and 3m (measured) at f1.5, f2, f4 and f5.6. The RF patch was aligned on each target, but the barrel mark was slightly off. The 1m and 2m targets were in fairly good focus at f1.5, and improved as I stopped down for subsequent exposures. The actual focus was just past the 3m target at f1.5. I'll post the images later this evening, if you like.
 
Sonnar Brian said:
Open a new thread up on this forum with the images.

We'll take a look at it.

https://www.ebay.com/itm/Jupiter-3-50mm-F1-5-1957-Silver-Pro-Shimmed-For-leica-M-Ex/303805019573

Too Funny. I looked at Jupiter-3's on Ebay, and this 1957 J-3 popped up. That's my daughter's red fingernail polish used to hold the set screws... "So Professional"...
Click to expand...

I have a J3 on my IIIc . exactly a twin with ser# 580.... Perfect shape. However, set screws do not show any fingernail polish. Is this a certainty that you never touched it!?
 
hap said:
I have a J3 on my IIIc . exactly a twin with ser# 580.... Perfect shape. However, set screws do not show any fingernail polish. Is this a certainty that you never touched it!?
Click to expand...

No- I learned the nail polish trick later on. I worked on so many of these lenses- the last 1956 KMZ J-3 I bought off Ebay, I had worked on it and sold it... Did not recognize it until I opened it up. I bought it because the SN was the highest I've seen on a KMZ. Did not know that much about them when I sold it!
 
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