Here is a panorama of a rainbow looking out from my backyard. Next time I need to get the top part of the double rainbow also. If you look closely you'll notice how the colors on the top rainbow are inverted from those on the bottom one. Also note how it is a near perfect semicircle. Since the sun is always in the opposite direction from the center of the circle that is formed by the rainbow, this means that it is almost exactly sunset in this picture.

For those of you that want to know more about rainbows these are actually the 1st and 2nd rainbows out of an infinite number. Because of the physics behind rainbow formation the 3rd and 4th rainbows would actually be in the exact opposite direction and you would not be able to see them since you would be staring at the sun. The 5th and 6th would be above the 1st and 2nd but far dimmer and so nearly impossible to see. 7th and 8th would again be towards the sun and the pattern repeats. There is also something called a zeroth order rainbow that usually just appears as an increased brightness in the direction of the sun. Occasionally you will see a halo around the sun or moon. Most likely this is actually caused from the refraction of light through ice crystals instead of water droplets.


Original image: 9000 x 3000 (27 MP) from 8 pictures.