Window Frost Patterns

February 15, 2011

Photographer: Heather J. Renyck
Summary Author: Heather J. Renyck

Frost forms on windows when the glass is exposed to sub-freezing conditions on the outside combined with comparatively moist air on the inside. Frozen dew is a variety of frost that forms when the air temperature drops below 32 degrees F (0 degrees C) but when the air is colder (near 15 degrees F or -10 degrees C) water vapor condenses directly on the chilled glass to form hoar frost. Imperfections on the surface of the glass, smearing, the presence of dust and pollen grains, etc. affect the frost pattern. In this case, it appears a spider's web had a significant influence on the design of the window frost. If you look closely, you'll notice sparkling colors in the frost crystals (upper right). These hexagonal crystals act like tiny prisms when sunlight passes through them. Photo taken from the window of a home in Meaford, Ontario on January 16, 2011.

Photo details: Camera Maker: OLYMPUS IMAGING CORP.; Camera Model: E-510; Focal Length: 35.0mm; Aperture: f/8.0; Exposure Time: 0.010 s (1/100); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; Exposure: Creative Program (based towards depth of field); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB.