An unusually fine large UFO inserted itself into a photograph taken on February 6, 1959, near Boulder, Colorado. The witness had spent the afternoon climbing on Flagstaff Mountain and, about 5:00 P.M., snapped a picture of the town of Boulder, to the southeast. Although he had seen nothing unusual in the sky or in the air, the negative, when developed, showed a small black blob that printed as a white, luminous, roughly spherical object--a typical flying saucer (see Plate VIIa). Civilian saucer investigators in the area procured a copy of the photograph and sent it to NICAP for evaluation. The witness himself did not immediately assume that he had photographed an interplanetary spaceship hovering over the city of Boulder; instead, he sent a print and a description of the circumstances to Dr. Menzel, who was well acquainted with the geography of Boulder and Flagstaff Mountain. Dr. Menzel suggested that the blob of light could have been produced by some type of reflection: “The sun appears to have been pretty low at the time. Is there, in the approximate position of the blob, some house with a fairly large window that could have been reflecting the sun? Stand at approximately the same spot and look over the region with a field glass. A bright spot like this often spreads enormously on the film. You can see from the picture that the sun must have been shining brilliantly. The shadow, especially of the large barn on the right, gives us some idea of the height of the sun. This was in February, and the angle of the sun will now have changed. Please make this test and let me know.” Not until the first week of May, however, was the witness able to repeat his excursion and make the necessary tests. Using a copy of his original picture as a guide, he was able to stand in the exact spot from which he had taken the picture. He then realized that the Law Building of the University of Colorado stood in the place occupied by the UFO and that the big double window of the Law Building was at the exact center. In May no reflection appeared, but from calculations he found that the position of the February sun was such that the window, when open at just the right tilt, would reflect the sun’s image to the exact spot on Flagstaff Mountain from which he took the picture. The image of the reflected sun is extremely bright and the film had been overexposed: therefore the image had spread on the film to create the large UFO. To confirm the hypothesis, the witness tried overprinting the negative so that the entire picture came out practically black, and with successively longer exposures the size of the bright UFO diminished. As he got it down to the smallest size on the blackest print, he could see the fuzzy outline of a window[XII-2]. _Unfamiliar Lights on Planes_