Sonnars 5cm F1.5 "T", two from 1943 that lead very different lives.

Sonnar Brian

Sonnar Brian

Product of the Fifties
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This thread gives the background for "Basket Case Sonnar", which underwent some of the same rebuilding that they gave to Steve Austin. Steve may have had this lens on the X-24 when he crashed, he was using it on his Contax.

https://www.rangefinderforum.com/node/4761698

The middle triplet is original, the front element is from a 1939 5cm F1.5 Sonnar "T" originally in Arriflex mount, the rear triplet is from a KMZ J-3 with Zeiss optics, and the Leica focus mount is from a 1951 KMZ J-3. The latter took a lot of work, was rough with enough corrosion to make the focus "not smooth". Uses a little more grease than I like, but focus is good- if not a bit heavy.

The all-original CZJ 5cm F1.5 Sonnar "T" is on the M8, both these lenses are from the same batch. This is an original Zeiss Leica mount. Optically- superb. The mount is fragile, but this one is the best I've seen. It still has a slight wobble in the mount. I prefer the Jupiter-3 mount, which is an improved design with the stop screw being moved to the internal mechanism rather than screwed through the focus ring.

I wanted to do a comparison of the images between the two. An overcast day- rained last night. I use the M8 for testing lenses, and used the same UV/IR cut filter for both. The image is cropped, but still good to compare the lenses. The M8 has a 0.5mm cover glass, a good feature for testing sharpness. I optimized the all-original Sonnar using a TTL viewer, bought it before I had the digital Leicas. Focus is good enough.
 
First up is "Basket Case" built out of Four Lenses- an optical group from three lenses, and the mount from the KMZ Jupiter. All Shots at F1.5 and F4.










 
"To my eye"- the Basket Case Sonnar is slightly warmer, the coating on the rear triplet is more of a magenta cast. I normally keep a Skylight filter on the all-original Sonnar when shooting color. No need for the Basket Case. I'm surprised the edge-to-edge sharpness of the basket case is this good. When "mixing and matching" lens groups, it is easy to get good center sharpness. The edges- can be a roller-coaster. This one is very smooth for a Sonnar.
 
The Sun popped out- chance to test the coatings on the Basket Case Sonnar.

Wide-Open, shot facing the Sun.



The Focal length on this "Hack-Job" is very close to the Leica standard. Close-focus is "ever-so-slightly" behind the RF, but well within F1.5 DOF.

This is a 100% crop of an airplane over my head, at F1.5. Good thing I had the M8.

Infinity-F15.jpg


Mid-range, F1.5.



The coatings are doing their job.
 
A "Postscript" to compare the Wartime 5cm F1.5 Sonnar "T" to the Nikkor-SC 5cm F1.5,

Nikkor wide-open on the M Monochrom.



And the Wartime LTM Zeiss 5cm F1.5 Sonnar, wide-open on the M Monochrom.



"I paid more for the Nikkor"... but it is even more rare than the Sonnar.

The Nikkor matches the 1936 5cm F1.5 Sonnar. The glass in the wartime lenses is "magic" and the formula was improved, the result- better edge-to-edge performance.
 
Thanks for posting this comparison.

I think this is a very good example where you can see the slightly different characteristics of the Jupiter-3 vis a vis to the wartime Sonnar. The Jupiter-3s are very aggressively optimized for lower levels of spherical aberration and high sharpness. You can see this over-correction very easily in the shot of the fallen log where the sharpness "peeks" through the background blur in the corner, this happens when you over-correct for spherical aberrations and it is also the cause for the strange soap bubble defocus that is usually more prevalent in Jupiter-3 lenses.
 
There is a Japanese Anime movie, "The Cat Returns", where the heroine makes Tea for her Mother and remarks something like "it never comes out the same way twice". I feel that way about Jupiter-3 lenses. I've worked on over 200 of them, and shot with them. Clever way to get a large sampling of lenses. I currently own about 20. They are like cups of tea, some great, most very good, and some that are lessons for the next one that you work on.



My 1952 KMZ J-3, glass transplanted into a 1950 barrel and placed in a new focus mount. Wide-Open.
 
If you have kept a record on each J-3 lens you worked on, I could analyze the data to see if there are any associations between certain factors present in the lenses or not. 🙂
 
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