Documents / FOIA release
This is a 1992 CIA History Staff monograph by Gregory W. Pedlow and Donald E. Welzenbach, originally classified Secret NOFORN and approved for release in 2013. It covers the CIA's manned overhead reconnaissance program from 1954 to 1974 and the two aircraft it developed, the U-2 and the A-12 OXCART. The history covers the U-2 overflights of the Soviet Union, the 1960 downing of Francis Gary Powers and later operations in Asia and Latin America. It also includes a section on U-2s, UFOs and Operation BLUE BOOK.
“The Advance”35 pages
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Baker's new lenses were used in a camera system known as the A-2, which returned to a trimetrogon arrangement because of problems with the A-1 system's rocking mount. The A-2 consisted of three separate K-38 framing cameras and 9.5-inch film magazines. One K-38 filmed the right oblique, another the vertical, and a third the left oblique. The A-2 system also included a 3-inch tracking camera. All A-2 cameras were equipped with the new 24-inch f/8.0 Baker-designed lenses. These were the first relatively large photographic objective lenses to employ several aspheric surfaces. James Baker personally ground these surfaces and made the final bench tests on each lens before releasing it to the Agency. These lenses were able to resolve 60 lines per millimeter, a 240-percent improvement over existing lenses. $ ^{18} $
Once Baker and Scott had redesigned the 24-inch lens for the K-38 devices, they turned their attention to Baker's new camera design, known as the B model. It was a totally new concept, a high-resolution panoramic-type framing camera with a much longer 36-inch f/10.0 aspheric lens. The B camera was a very complex device that used a single lens to obtain photography from one horizon to the other, thereby reducing weight by having two fewer lenses and shutter assemblies than the standard trimetrogon configuration. Because its lens was longer than those used in the A cameras, the B camera achieved even higher resolution—100 lines per millimeter.
The B camera used an 18- by 18-inch format, which was achieved by focusing the image onto two counterrotating but overlapping 9.5-inch wide strips of film. Baker designed this camera so that one film supply was located forward, the other aft. Thus, as the film supplies unwound, they counterbalanced each other and did not disturb the aircraft's center of gravity.
The B camera had two modes of operation. In mode I, the camera used a single lens to make seven unique exposures from $ 7 3. 5^{\circ} $ on the far right and far left obliques to vertical photos beneath the aircraft, effectively covering from horizon to horizon. Mode II narrowed the lateral coverage to $ 2 1. 5^{\circ} $ on either side of vertical. This increased the available number of exposures and almost doubled the camera's Not linked to a story yet.
FOIA release, from the cia-readingroom collection. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 406 pages are in the text index: search them above, or from the library's search.