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geobedell
Joined: 20 Nov 2001 Posts: 5 Location: tallahassee fl
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Posted: Tue Nov 20, 2001 8:06 pm Post subject: |
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i recently purchased an old tessar to use on my super graphic - it was clean enough, and only 70 bucks because it was uncoated. i'm wondering about this whole coating thing though, as the lens is quite sharp, and has good contrast. the lens is marked carl zeiss jenna #2370372, 13,5cm, f4.5, and is mounted in a compur shutter. any thoughts? |
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Les
Joined: 09 May 2001 Posts: 2682 Location: Detroit, MI
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Posted: Tue Nov 20, 2001 9:08 pm Post subject: |
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The more air to glass surfaces you have, the more light and image is lost. Coating helps reduce interal reflections and this light loss. Ans since this light loss isn't bouncing around, the image is sharper.
Consequently a multi element like a Planar or a double gauss lens like a WF ektar will benefit more from coating than say a Dagor or Tessar.
Depending onthe lens design you may or may not find some color fringing when you shoot chromes. |
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geobedell
Joined: 20 Nov 2001 Posts: 5 Location: tallahassee fl
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Posted: Tue Nov 20, 2001 9:45 pm Post subject: |
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les,
thanks for your reply. actually, what i was wondering more about is if it might in fact be coated. i'm sort of trying to figure out what the vintage of the lens might be, and if the serial # etc, might give someone enough clues.
thanks,
gb |
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Les
Joined: 09 May 2001 Posts: 2682 Location: Detroit, MI
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Posted: Wed Nov 21, 2001 3:19 am Post subject: |
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http://www.craigcamera.com/zeisslen.htm
These numbers were derived from prototype lenses with both numbers and a production year. It sounds a lot like Graflex numbers-there's a certain amount of latitude.
Also early coating were soft, and it's common to see leicas that WERE coated now with only a hint of coating around the edges. Also true is that glass naturally oxides and creates what is called bloom--a natural coating. |
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geobedell
Joined: 20 Nov 2001 Posts: 5 Location: tallahassee fl
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Posted: Wed Nov 21, 2001 3:52 am Post subject: |
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les,
thanks again for the info, it was very helpful. the serial #'s and dates were exactly the type of thing i was looking for. this whole sight has been very informative.
gb |
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danimal
Joined: 22 Jun 2001 Posts: 48 Location: Upper Sonoran Desert
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Posted: Tue Nov 27, 2001 11:23 pm Post subject: |
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Hi geobedell, I have the same lens and I like it a lot. If I remember things correctly, a CZJ lens is prewar and therefore not coated. Well, Zeiss did hard coat a few lenses before the war, but I think that they were small format lenses. The Tessar is a great design. It's simple and doesn't need coating as much as the new mulit-element zooms and superwides. As Les mentioned, a simple lens like a Tessar with few air-to-glass interfaces is Ok without coating. Tessar formula lenses are still being manufactured after 100 years, so there must be something good about the design. My personal opinion is that uncoated lenses represent great values. You get a lot of lens for dirt cheap. You wrote that you like the results that the Tessar gives you. Since you're happy, it's a good lens, right? Dan
_________________ The opinions expressed are solely those of the author. You are free to disagree as long as you don't mind being wrong. |
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geobedell
Joined: 20 Nov 2001 Posts: 5 Location: tallahassee fl
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Posted: Wed Nov 28, 2001 12:08 am Post subject: |
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dan,
it's hard to argue with good results isn't it? i may have to pick up an old goerz dagor next. part of the beauty of shooting vintage equipment (speed graphics, etc.) is realizing that life existed before super-multi-coating and matrix metering. i was just looking through the jim stone textbook for large format, and saw a great image - alfred steiglitz making one of his cloud images with a giant old Graflex slr. it looks like he's playing the tuba!
thanks for your input,
gb |
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