Heiligenschein
'halo, aureola') is an optical phenomenon in which a bright spot appears around the shadow of the viewer's head in the presence of dew.In photogrammetry and remote sensing, it is more commonly known as the hotspot.[1] Nearly spherical dew droplets act as lenses to focus the light onto the surface behind them.This configuration is similar to a cat's eye retroreflector.When dew droplets are suspended on trichomes at approximately this distance away from the surface of a plant, the combination of droplet and plant acts as a retroreflector.