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awk026
Joined: 22 Jul 2004 Posts: 1 Location: South Africa
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Posted: Thu Jul 22, 2004 12:52 pm Post subject: |
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I'm keen to know of anyone's experience/opinion of this lens, which was made for the Graflex XL series.
From what little info I've been able to find out to date, it's reputed to be extremly sharp, and is refered to as a "rare element" (or is that "rear" element?) lens. What exactly does that mean?
Further if anyone is able to give me an idea of what this lens would typically sell for I would be most grateful; is it particuarly hard to find? |
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45PSS
Joined: 28 Sep 2001 Posts: 4081 Location: Mid Peninsula, Ca.
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Posted: Thu Jul 22, 2004 7:54 pm Post subject: |
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A rare element usually refers to RADIOACTIVE materials used in making the glass. Low level stuff, may fog film if left on a loaded camera for several hours, might cause a cancer if you carried it in your pocket 12-18/7.
To test for radioactivity sit suspect lens on an unexposed sheet of film for 24 hours then process as normal (keep film light safe). If a circle is present where the lens was it is radioactive.
Polaroid shet film is perfect for this test.
_________________ The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU. |
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t.r.sanford
Joined: 10 Nov 2003 Posts: 812 Location: East Coast (Long Island)
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Posted: Fri Jul 23, 2004 1:24 pm Post subject: |
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If memory serves, "rare earths" include nonradioactive materials like lanthanum and ytterbium. They can be added in small quantities to molten glass, changing the refractive index and so giving optical designers more options. It seems reasonable that Voigtlander's "Apo-Lanthar" was so called because lanthanum was used to dope the glass.
The "Ysarex" has an excellent reputation. Rodenstock makes good stuff. |
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