On Wed, Nov 21, 2018 at 11:37 AM Igor PDML-StR <pdml...@komkon.org> wrote:
> This shot got me wondering about its truthfulness: > https://www.dailymail.co.uk/travel/travel_news/article-6405507/The-stunning-winners-panoramic-photography-awards-revealed.html > The round-shaped rainbow with the arc exceeding 180 degrees that did not > get distorted despite panoramic stitching. Rainbows are circular (they form a 42-degree circle around the anti-solar point). If you're not used to seeing them that way, I think it's for two reasons: The projection used by rectilinear lenses distorts the circular shape if the rainbow is off-center, and quite often most of the rainbow is below the horizon, so we only see the top portion, which I think fools the eye into thinking it's more like a parabola or other shape. Panorama stitching software usually has a number of options for the projection, and I assume at least some of them preserve the true circular shape. You can see more than 180 degrees of a rainbow if you are up high and have rainy air below you. Pictures of >180 degree rainbows taken from aircraft are fairly common; see, for example: https://apod.nasa.gov/apod/ap140930.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
