It has been contended that "glare" from sunlight reflecting back to the observer could have obscured the lower parts of the blimp, leaving the witnesses with only a clear view of the upper portion, thus leading them, to believe that there was only a top fin on the Rogue River object.
I have already countered that this is unlikely because the motion of the blimp (first toward, then turning and angling away from the observers) would have shifted the "glare" so that features should have been alternately revealed and obscured over time - especially as neither the observers nor the light source moved.
However (of course) this was too subtle an argument for the skeptics to accept (not being "specialists" in observation) so I decided that a better "proof" against the "glare" hypothesis was possible.
I have now studied over 1000 blimp photos (Google Images -“Blimp” or “Blimp Photo”, etc) and have tried to select from those pictures that show maximum “glare” from the blimp while representing as close as possible the conditions at Rogue River on the day (see attached images).
According to witnesses the sky was clear and the sun was low at their backs. The time of the sighting was about 1700 hrs (5pm) and according to (
www.aa.usno.navy.mil/data/docs/AltAz.php) the sun at that time was at 38 deg. elevation and 263 deg. azimuth (thus Astrophotographer’s 30 deg. was an incorrect guess – as I suspected it would be).
To explain what is occurring with reflected light off a blimp we first must recognise that there are three types of reflection possible: Specular, Diffuse and Semispecular (a mix of the first two). Specular reflection is when light is reflected back as a “beam” such as light off a mirror. This is where the angle of reflection equals the angle of incidence and it creates the “glint” phenomenon - and it is well known that this "glint" can obscure the view of reflective objects. And this is where the "glare" hypothesis arises from. Diffuse reflection is where the light is reflected from a surface equally in all directions - and there is no “glint” – such as off a piece of matte-white paper. Semispecular is a mixture of both types, but where the intensity of the reflection is greater where a specular “glint” would have been - but also brighter spreading over the surrounding area, becoming more diffuse the further away. This semi-specular type of reflection is the type of reflection that is apparent from blimps.
If one observes the pictures attached (I would have uploaded more but there is a limit on the number one can upload in this forum but they are representative) one can see this phenomenon quite clearly. What is also apparent however is that there is no “glint” or “glare” as described in the hypothesis that would “block out” part of the image while leaving other parts visible. For example in pictures 1, 5, and 10 we can observe the closest a blimp will ever come to a “glint” - but you will also note that the details inside the brightest area of reflection - remain visible. Other pictures show the semispecular reflections at various angles of flight – but at no time do the details of the blimp get lost in the “glare” from a reflection – as contended in the “glare" hypothesis. As can also be noted, when the blimp is not front on, but more side on, the “glare” is elongated proportionally - but again, never reaches "glint" proportion that would block viewing conditions.
This then is the proof against the “glare” hypothesis.
