UN EXEMPLE D'ANALYSE DE CLICHES D'O.V.N.I. : L'ETUDE DES PHOTOGRAPHIES DE MC MINNVILLE (USA)

This document, issued by the Centre National d'Etudes Spatiales (CNES) in Toulouse on June 7, 1977, under the GEPAN (Groupe d'Etude des Phénomènes Aérospatiaux Non-identifiés) banner, provides a critical re-evaluation of the famous 1950 McMinnville, Oregon, UFO photographs. The report, authored by Claude Poher, serves as a technical critique of previous analyses conducted by Professor William K. Hartmann for the Condon Commission and later by Bruce S. Maccabee. The McMinnville case involved a couple who claimed to have photographed a metallic, disc-shaped object in broad daylight. Hartmann had originally concluded that the object was likely a distant, large, and extraordinary aerial vehicle. Later, critics Philipp Klass and Robert Sheaffer argued that the images were a hoax, suggesting the object was a small model suspended near power lines, and that the apparent brightness was due to lens defects or dirt. Poher's report systematically reviews the history of the case, including the involvement of the Condon Commission and the subsequent debates. Poher employs advanced photometric and geometric analysis, utilizing a micro-densitometer to examine the original negatives. He argues that while Hartmann and Maccabee's photometric measurements were detailed, their interpretations were flawed. Poher concludes that the object was, in fact, a small, translucent model suspended by a thin, invisible wire from electrical cables. He supports this by demonstrating that the geometric perspective and the photometric data are consistent with a small object close to the camera rather than a large, distant one. Furthermore, Poher includes additional annexes discussing other cases, such as the San Jose de Valderas and Aluche observations, which he also dismisses as hoaxes linked to the 'Ummo' affair. The document concludes that the McMinnville photographs are a 'supercherie' (hoax) and emphasizes the importance of rigorous, scientific analysis of daylight photographs, noting that such cases often reveal human-made fabrications rather than extraordinary phenomena. Poher expresses frustration with the lack of authentic daylight UFO photographs and calls for investigators to prioritize the acquisition of original negatives to avoid being misled by hoaxes.