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Dave
Joined: 05 Dec 2003
Posts: 78
PostPosted: Sat Jul 17, 2004 2:24 am

In May some of you guys were talking about grotesque lenses, <i>a propos</i> 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.

<IMG SRC="http://i10.ebayimg.com/02/i/02/22/b0/92_1_b.JPG">

glennfromwy
Joined: 29 Nov 2001
Posts: 903
PostPosted: Sat Jul 17, 2004 3:49 am

Ohhhhh my gosh, I gotta have one of those!
Nick
Joined: 16 Oct 2002
Posts: 494
PostPosted: Sat Jul 17, 2004 11:02 am

Quote:

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.


Shouldn't wavelenghts be in nanometers?
t.r.sanford
Joined: 10 Nov 2003
Posts: 812
PostPosted: Sat Jul 17, 2004 3:10 pm

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?
Dave
Joined: 05 Dec 2003
Posts: 78
PostPosted: Sat Jul 17, 2004 7:04 pm

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.

<font size=-1>[ This Message was edited by: Dave on 2004-07-17 12:05 ]</font>
glennfromwy
Joined: 29 Nov 2001
Posts: 903
PostPosted: Sat Jul 17, 2004 7:42 pm

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.
Les
Joined: 09 May 2001
Posts: 2682
PostPosted: Sun Jul 18, 2004 3:24 am

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
glennfromwy
Joined: 29 Nov 2001
Posts: 903
PostPosted: Sun Jul 18, 2004 7:58 pm

Makes me wonder if this thing is a remnant of the U-2 spy plane program.
Henry
Joined: 09 May 2001
Posts: 1662
PostPosted: Sun Jul 18, 2004 8:21 pm

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.....
Graflex Sid
Joined: 10 Jan 2003
Posts: 221
PostPosted: Mon Jul 26, 2004 7:21 pm

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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