Observed phenomena: Pollen corona
Light source: Sun
Origin: Birch pollen
Observing place: Tampere, Finland
Observing method: Photography
Technical information about photographing equipment: Camera: Canon EOS 1000D, lens: Canon EF-S 18-55mm
On 22th of May 2012, I observed a nice low altitude birch pollen corona in Tampere, Finland. The birch pollen coronas are only slightly oval -shaped with high solar altitude, but when the Sun is at low altitude, the pollen corona gets stretched vertically and the oval -shape of the corona gets intensively pronounced!