Quote Originally Posted by Hikari View Post
That is not flare. Flare in non-image forming light and there is an image of a rainbow. Did you take a roll out of a camera and forget you had shot a rainbow frame? It looks like a double exposure.
Real rainbows don't look like that. A double exposure would have shown more of the 'other' image too. A rainbow is typically faint and not the brightest part of the image.