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8" F5 40"fl Perkin Elmer Lens - Need info

Started by tomrod, 07/21/2002 11:06AM
Posted 07/21/2002 11:06AM Opening Post
I just bought an 8" F5 fixed focus camera lens. The objective is marked "DISTORTIONLESS TELEPHOTO AERO LENS 40" (1016MM) F/5.0 T5-Y7-068 MADE IN U.S.A. BY PERKIN-ELMER CORPORATION, NORWALK, CONNECTICUT" and there is another label marked "FIXED FOCUS LENS" and "Gorton Industries".

It appears to be a four element design with an 8" two element air spaced objective and a 5" two element corrector about 2 ft down the tube from the objective. Is anyone familiar with this lens?

There is no fucuser, but I did hand hold a couple eyepieces in the 25mm to 55mm range and with the proper orientation was able to get some views without much color. I assume that collimation is critical on an F5 lens. I have a way to install a focuser without hurting the tube. How do I check collimation when I install it?

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There are only 10 kinds of people who understand binary - those that do and those that don't
Posted 07/21/2002 04:05PM #1
What you have obviously is an old aerial camera lens probably used in high altitude a/c such as a U-2, TR-1, or maybe even an SR-71. They were designed for very high altitude (hence fixed focus) on either 5x5 or 9x9 format film (inches). Most of those type lenses were designed for use with deep orange or red filters for maximum haze penetration with B&W films. However some in later years were designed to be used with color trans films specially designed for aerial photography. When I was in the Navy we used these type cameras in the RA-5 for "standoff" photography because of their extremely high resolution. As a matter of fact most of the specialized optics used then were classified but no longer(at least the generation you have). I would imagine that it would make a fine "wide field" camera using as large a format as you can get, most definitely up to 4x5 or 5x7, but even 120 would be useful as you would be in the "sweet spot" all the time. As for visual use, I would imagine an ota made from the optical tube you have would be fairly heavy so a pretty massive mount would be of absolute necessity! Good luck!

Walt
Posted 07/21/2002 04:41PM #2
You could collimate it pretty easily using a holographic laser collimator with concentric rings, there are also refractor collimating eyepieces made for the purpose.
Are you going to make full use of the huge sharp photographic field that thing has with a four inch or larger focuser? I'd be temped to find an old metal view camera with rack and pinyon focusing and attach that to it some how. How much does that whole assembly weigh ?