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Dave
Joined: 05 Dec 2003 Posts: 78 Location: Canada
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Posted: Sat Jul 17, 2004 2:24 am Post subject: |
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In May some of you guys were talking about grotesque lenses, a propos Graflex Big Berthas.
Just for interest, have a look at this 100" (2500mm) f/12.5 Kodak Infared Ektar listed on ebay. I assume this thing was for aerial photography. It's physically huge, and weighs 75lb.
Interesting that they specify the wavelengths it's optimized for. Or at least I assume that's what the designation '0.8 to 1.0 microns' means.
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glennfromwy
Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming
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Posted: Sat Jul 17, 2004 3:49 am Post subject: |
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Ohhhhh my gosh, I gotta have one of those!
_________________ Glenn
"Wyoming - Where everybody is somebody else's weirdo" |
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Nick
Joined: 16 Oct 2002 Posts: 494
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Posted: Sat Jul 17, 2004 11:02 am Post subject: |
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On 2004-07-16 19:24, Dave wrote:
Interesting that they specify the wavelengths it's optimized for. Or at least I assume that's what the designation '0.8 to 1.0 microns' means.
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Shouldn't wavelenghts be in nanometers? |
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t.r.sanford
Joined: 10 Nov 2003 Posts: 812 Location: East Coast (Long Island)
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Posted: Sat Jul 17, 2004 3:10 pm Post subject: |
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Nowadays they are, as part of the ongoing process of detaching measurements from real-world referents. Back when wolframite was tungsten, visible-light wavelengths were given in millimicrons (a "micron" is a millionth of a meter). Visible light covered a spectrum from about 380 to 700 millimicrons, thus 0.38 to 0.7 micron -- and this lens, computed for the near infrared, is optimized for 0.8 to 1.0 micron.
Does anyone know what diameter image circle the 100-in. lens produces? |
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Dave
Joined: 05 Dec 2003 Posts: 78 Location: Canada
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Posted: Sat Jul 17, 2004 7:04 pm Post subject: |
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Apparently covers 5" x 7" anyway-- says so on the lens front. Given the size of the film, this is not that extreme a focal length-- it's in the ballpark of a 500mm lens on 35mm.
[ This Message was edited by: Dave on 2004-07-17 12:05 ] |
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glennfromwy
Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming
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Posted: Sat Jul 17, 2004 7:42 pm Post subject: |
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After being confused to death about microns, millimicrons, etc in old literature about infared photography, I have come to the conclusion that somewhere down the line it was changed to nanometers. I could be wrong but that's the only explanation that made sense to me.
_________________ Glenn
"Wyoming - Where everybody is somebody else's weirdo" |
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Les
Joined: 09 May 2001 Posts: 2682 Location: Detroit, MI
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Posted: Sun Jul 18, 2004 3:24 am Post subject: |
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I'm also guessing that given the relatively slow aperture, that this was more of a celestial lens rather than aerial.
Either that or they were VERY high up (which would explain the Infra red...cuts through a lot of clutter.
Les |
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glennfromwy
Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming
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Posted: Sun Jul 18, 2004 7:58 pm Post subject: |
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Makes me wonder if this thing is a remnant of the U-2 spy plane program.
_________________ Glenn
"Wyoming - Where everybody is somebody else's weirdo" |
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Henry
Joined: 09 May 2001 Posts: 1646 Location: Allentown, Pennsylvania
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Posted: Sun Jul 18, 2004 8:21 pm Post subject: |
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I think it was a prop in a burlesque show I saw years ago in Buffalo. There was a hilarious sketch with a view camera, a comedian, and a scantily clad female. Modesty compels me to refrain from summarizing the action that followed..... |
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Graflex Sid
Joined: 10 Jan 2003 Posts: 221 Location: London,England
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Posted: Mon Jul 26, 2004 7:21 pm Post subject: |
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This is the NEW lens the press boys will have to use in the future when they get pushed further back behind barriers to photograph celebrities..
"Look at the lens,honey!"
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