Documents / FOIA release
This Central Intelligence Agency memorandum to the Director of the National Photographic Interpretation Center, dated 17 February 1967, reports a photo analysis of Polaroid pictures of an alleged UFO taken on the shore of Lake St. Clair, Michigan. The photographs came from the Aerial Phenomena Office at Wright-Patterson AFB, and Major R.W. Nyls of the USAF supplied measurements of the site. The analysts estimated approximate dimensions from several stated assumptions. They found no definite evidence of a hoax, noted suspicious features, and called the result inconclusive.
Read from the scan by GLM-OCR; expect the odd misread word.
photographs (attachments 6, 7 and 8). These photographs along with the measurement sketches and investigation report provided a means of obtaining an approximate photographic scale. This scale value was then used to obtain approximate dimensions of the UFO. However, to do this the photo analyst had to first make major assumptions. These assumptions were necessary in a photo analysis of this type where insufficient data is available or in doubt. If any of these assumptions are in error the obtained dimensions are likewise in error.
## 4. The assumptions used in this photo analysis are as follows:
a. UFO was at a distance of 0.25 miles from camera station when photographed (this information supplied by Major Nyls in his investigation report).
b. The measurements supplied by Major Nyls are correct as stated.
c. Photographs shown in attachment 1 and 2 are full format.
d. UFO photographed was circular with plane of tail section perpendicular to camera axis.
e. The distance between the camera station and the object was large enough so that adjustments to the camera focal length need not be considered.
5. Attachment 9 represents in artists rough conception of the UFO along with the averaged dimension obtained from the mensural analysis of the photograph shown in attachments 1 and 2. Again, the user of this information must be cautioned that the dimensions shown here are only approximations based on assumptions. The quality of the photography, the crude estimation of the distance from the camera station to the object, the lack of original prints and precise camera data all tend to invalidate the answers. A good example of how the dimensions could change is illustrated by any change in the distance of the object from the camera station. The dimensions will change in direct proportion as the ratio of any new distance divided by the 0.25 mile distance that was used, i.e. 0.20 mile $ ^{-1} $ 0.25 mile $ = $ 0.80; therefore, causing the new values to be 80% of the original values. 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. 6 pages are in the text index: search them above, or from the library's search.