Soap bubble freezing in real time, outdoors with an air temperature of minus 15 degrees Celsius (5 F). The thin crystals of dendritic ice spread over the surface of the bubble as the water freezes. These patterns are known as fern frost, due to the resemblance of the crystal pattern to the fronds of a fern. Filmed in St Paul, Minnesota, in winter.
Model release not required. Property release not required.