Tuesday, May 06, 2008

Rainbows and supernumeraries

During last weekend (Sunday 4th May -08) at city of Espoo, I observed seasons first rainbow. Local thunderstorm came along with rainshowers produring primary and secondary bows. I visually saw 3 primary supernumeraries.

In the heavily enhanced image (USM) of primary bow there is small hint of 4th supernumerary visible (1). Outside of seconday bow (2) there is larger arc (dark pink color), assuming it indicates supernumerary also... The droplet sizes may been quite even, due to easily visible interference bows.

Thursday, May 01, 2008

Heiligenschein and dewbow in moon light

Well, I wanted to observe moon halos that evening, but the sky was totally clear without any cirrus clouds.
I noticed that some blades of the plants on a field were rather wet. I walked some steps into the field and immediately noticed a clear brightening around the shadow of my head. I did a few steps to the left and to the right and could see a very faint dew bow. So I took some photographs at different exposure times and ISOs. The best photographs (1 2) I achieved using stop 4, an 18-mm-lens and at a time of exposure of 45 seconds at ISO 400.

Author: Michael Großmann, Kämpfelbach, Germany