Or a lunar halo -original message- Subject: Re: Reverse Rainbow From: Tina Manley <images@xxxxxxxxxxxxx> Date: 05/05/2012 3:05 pm Probably a sun halo: http://en.wikipedia.org/wiki/Halo_(optical_phenomenon) Tina On Sat, May 5, 2012 at 3:01 AM, YGelmanPhoto <ygelmanphoto@xxxxxxxxx> wrote: > Here is something puzzling. > > Last week I looked up into the clouds and was startled by an arc of a > rainbow that was not concentric about the sun. In fact the sun was rather > low, in the late afternoon, and the rainbow was quite high. In the image > in my dropbox at this link<http://dl.dropbox.com/u/26687258/IMG_0843A%20copy.jpg>, > the location of the sun is approximately at the red X in the lower left. > The sky in the direction of the sun was cloudy but the sun was very > apparent (although not as apparent in the image). The rainbow persisted > for at least fifteen or twenty minutes, dying down gradually but not > changing position. > > I tried to think of what light source could produce the rainbow as I saw > it. I tried to conceive a large structure sitting behind me, some distance > away, that might reflect sunlight so that perhaps the rainbow could be > concentric (in projection) around that. Perhaps some kind of water body, > or a highly reflective building, but I couldn't think of one and anyway I > didn't think that would do. > > But later, about an hour, when I went outside to look again, I looked way > up. What I saw was a bright half moon. So here's my question: Could the > moon have been bright enough to produce the rainbow I saw in the clouds > above me? I think the relevant angles might have been somewhat > appropriate, but I didn't check. In one hour the moon moves fifteen > degrees; I should have measured the angle between the moon as I saw it and > the direction to where the rainbow was . . . but I didn't. > > In full disclosure, I took the photo with a 5D Mii, with my lens set to > 35mm, and the only post processing I did was to add the X for the sun and > used Genuine Fractals to reduce the size of the image to 6 x 9 inches. > > Comments, please? > -yoram > -- Tina Manley, ASMP www.tinamanley.com
