Elmar Schmidt was travelling southwards after the 10th Conference on Light and Color in Nature in Maryland. He observed this spectacular pyramidal halo display in central Virginia on 22 June. The display lasted for at least 2 1/2 hours and showed several odd radius halo rings and their tangent arcs.
As Elmar Schmidt tells: “All in all the phenomenon looked spectacular and eery with the broad belt starting at the 18-deg-radius. Of note is also its quite southerly location and the longevity, which might be interesting to compare with simulations, especially at the sun’s elevation of 57 degrees.” ( 1 )
Further images of the display between solar altitude 54 and 29 degrees are also available ( 2– 3– 4– 5 )
Look here for a first analysis and more USM photos
I will get color slides too.
The 20° halo is nicely discernible. The other rings seem to be 9°, 18° 23° and 35° halos. Also, there are plate arcs from poorly oriented crystals, namely 18° and 23° plate arcs.
I finally received my slides, and YES, Jukka, there is the 35 degree ring, clearly seen on the original exposures.
I will post scans a.s.a.p.