Shafovaloff1
Well-known
Since I am almost always trying to figure out how something works so I can fix something I try to imagine how it was designed and manufactured. So, I remembered I had copied some information from Rick Oleson on how the ribbons are affixed to the clutches of the Contax II so there is little, if any difference between the acceleration of the two curtains. That explains my observation that the Contax I and II at least have the parallel sides on the images seen on the CTR. Also, I am no longer worried so much about the thickness of the ribbons (by my calculation 0.12 mm on the Contax I) as I like the idea that the two curtains are matched to move together as part of the operational design. In his design of the SLR, Rectaflex, Corsi provided for matched acceleration of the curtains by making the take-up spool for the first curtain and the end ribbon spool take-ups for the second curtain as spirals to account for the thickness of the ribbon and the curtain material. I am not so familiar with Leica design but did not see such a thing in their early design in what I have done replacing the curtains in the Barnack type copies, Nicca and Leotax. LIke touching up a paint job the more I look the more I see I miss. However, at some point I was concerned with the depth of the take-up end spools on the Contax I and realized that there was an acceleration possible from the winding up of the spools at either end. Also, the piece of leather on the Contax I running the length of the spool seemed to me to be there to aid any lost acceleration during the end of shutter curtain movement. That leather is beveled but how or why that adjustment is made I still would like to know, ok a shutter brake or damper function too. However I remember seeing that the Contax IIa had a curtain bounce problem that had a design fix.
I was wondering about cleaning the prism on the Contax I until going through some posts I saw that Leitz silvered prism ends to reflect but Zeiss relied on physics...so cleaning the end of the prism resulted in a nicer reflection! Where was I to get that information but here, so thanks again for your help and patience.
Tom Shafovaloff
I was wondering about cleaning the prism on the Contax I until going through some posts I saw that Leitz silvered prism ends to reflect but Zeiss relied on physics...so cleaning the end of the prism resulted in a nicer reflection! Where was I to get that information but here, so thanks again for your help and patience.
Tom Shafovaloff
Shafovaloff1
Well-known
The "Bee" on the Contax 1(e) showing the entire image with "capping" before repair. 
Shafovaloff1
Well-known
Regarding "titirisol" post on the Sonnar 1.5 50mm. I saw a 50mm 2 Sonnar sold on a Contax I on the ehay site and thought it odd. What I could find was that with lens early design f2 was improved by reducing "air" between elements which was how Zeiss got from the f2 to the f1.5, that is. by reducing the number of groups with air between them...arriving at a thicker lens but faster. Later speed was gained by coatings. If I had know that the lens was such an early example I might have made an effort to buy the 50mm f2 but the 1.5 is such a beautiful lens....some day, it will have to be sooner.....
Tom Shafovaloff
Tom Shafovaloff
boojum
Mentor
My remembrance from discussing the II with its owner in the mid-fifties was that the metal focal plane shutter cured the Leica problem of burned shutter curtains when leaving off the lens cap in the sunlight.
boojum
Mentor
Let me caution you that fluent German would help only a little. Technical German is a complex world of its own. Technical German has its own dictionaries, vocabulary usw. It's definitely not Göthe. "Ich weiß nicht was soll es bedeuten . . . " ;o)
Shafovaloff1
Well-known
David Hughes...boojum...ever hear of Google Patents?
boojum
Mentor
I'm a Liberal Arts major. Do you want fries with that? Ask me about the Hoover Administration domestic oil policy. That was my area of concentration. LOL
I just checked it out on Klystrons, the bread and butter of a former employer.