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Post by nikonbob on Sept 11, 2007 17:51:02 GMT -5
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PeterW
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Post by PeterW on Sept 11, 2007 19:36:00 GMT -5
For a 70 year old lens, or a lens of any age for that matter, the results look pretty good to me. I've got a 1.5 Sonnar on my 1936 Contax II. It's a slightly later lens, 1938, and it is coated.
I've had the camera about 20 years, and I love it, but don't use it very often these days because of the age of the shutter and the fact that it's quite a rare model, one of the first 1,000 made before Zeiss Ikon modified the sequence of the shutter speeds. But I run a film through it every so seldom to keep it exercised, and when I do I'm always impressed by the quality of the lens.
PeterW
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Post by nikonbob on Sept 11, 2007 20:08:57 GMT -5
PeterW
It is a small world, my Contax II is supposedly made as part of batch in 1936/37 with the serial number prefixed by a C. The collapsible 50/2 that came with it was made in 1937 by serial number. I think I got quite lucky in the fact that the new Sonnar 1.5 was also 1937 made. I am starting to think that CZJ started to coat their lenses around 1938. Could you explain the change made to the sequencing of the shutter speeds? It would be interesting to check mine when it comes back from overhaul. You know I am starting to like the CZJ and FSU clone lenses better than the Leicas I have.
Bob
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PeterW
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Post by PeterW on Sept 12, 2007 6:35:25 GMT -5
nikonbob wrote
You raise some interesting points, Bob.
After the first batch of 1,000 or so cameras Zeiss Ikon made two small changes to the Contax II.
The first batch had straight vertical knurling on the wind-on knob, but after that the knurling was the familiar 'small square' pattern. This was probably just part of a general change in Zeiss Ikon tooling as the Contax I and the original TLR Contaflex knobs had straight knurling but the Super Nettel had the small square pattern. As far as I know the rewind knob on the Contax II always had small square knurling.
The only change to the sequence of the shutter speeds was that the early batch ran ..... 25, 50, 100, 250, 500 .... Subsequent speeds ran ..... 25, 50, 125, 250, 500 ..... Whether there was any change in the actual shutter speed I don't know. I think it's more likely that it was just a re-engraving to fall into line with the then new DIN recommended speed sequence.
Modern lens coating was developed by a Ukranian optician Alexanda Smakula who went to work for Carl Zeiss in 1934. He patented the process in 1936, and Zeiss started to coat lenses during 1937 but it took till 1939 or 1940 for the whole range of camera lenses to be coated. Precedence was given to binocular and gunsight lenses for military use, but coating wasn't, as popular mythology would have it, a State Secret till after the war. Smakula's patent was too widely published for that.
With regard to Leitz and Zeiss lenses, we're really looking at two development philosophies. Leitz concentrated on definition but designers at Zeiss were willing to trade just a shade of definition, mainly at the extreme edges at full aperture, to obtain better contrast, what became known as 'perceived sharpness'. Somewhat similar to using Unsharp Mask in PS.
Ludwig Bertele, who designed the Sonnar, was persuaded to follow this philosophy and achieved a degree of contrast and reduction of flare that was exceptional at the time for a six-element lens. This, IMHO, put Zeiss ahead of Leitz in the opinion of many photographers for a good few years, coating or no coating.
I can't check the serial number of my Contax at the moment because its inside and there's a film in it. But I'll let you know what it is when I've finished the film. The lens, btw, is non-collapsible.
PeterW
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Post by nikonbob on Sept 12, 2007 7:55:49 GMT -5
PeterW
Thank you very much for your detailed reply and the additional info is very welcome. I had hoped that the 5cm 1.5 Sonnar would be coated but I am not in anyway disappointed that it is not. It could be, in part, that the more contrast/perceived sharpness philosophy is what I like but there is something else that makes a difference that I can't put a finger on. It would be enough to convince me to buy new Zeiss glass for M mount cameras over their modern Leica equivalents. Considering the price difference that would make it a no brainer. That is all theory as I don't see myself paying that kind of coin for a new lens any time soon. Besides the oldies deserve a new lease on life.
Bob
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Post by doubs43 on Sept 12, 2007 13:21:35 GMT -5
Bob, those are impressive shots without regard for the lens or camera that took them. IMO you've scored very nicely with the Sonnar.
Oddly enough, I have three 50mm f/2 Summitars for my Leicas. The last one I purchased was made in 1939 and I fully expected it to be uncoated. It's not and from all indications it has the original factory coating. It's widely claimed that the majority of Summitars will have cleaning scratch marks on the front coating but either I'm very lucky or the claim is not correct. All three of mine are perfect in that regard.
Walker
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Reiska
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Post by Reiska on Sept 12, 2007 14:49:00 GMT -5
That Sonnar looks like an excellent lens and it is hard to believe, that it is uncoated. I have a nice looking Jupiter-3 which is more or less a copy of Sonnar 50/1.5. Could anyone tell more about it because I have also heard claims, that they are not exact copies, even if you forget the quality standard. There might have been some variants of that lens too.  This is a screw mount lens for Zorki and I feel shamed to say, that I have never used it. |
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Post by herron on Sept 12, 2007 21:55:30 GMT -5
Reijo:
I have several Jupiter lenses, but no f/1.5. That's a super-looking lens. I'm dying to know how good it is!
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