Polarized Window Frost
February 24, 2013
Photographer: Daniela Rapava; Daniela's Web site
Summary Authors: Daniela Rapava; Jim Foster
The photo above shows both frost crystals and two curious multi-colored ribbons on a window of my home in Rimavska Sobota, Slovakia. The variegated ribbons are actually drips of meltwater imaged using a circular polarizer lens. A polarizer filter or lens acts to recombine the two distinct rays of light that emerge when a beam of sunlight propagates through a slurry of partially frozen crystals as in this case. Because the rays were out of phase when recombined, the new rays contain nearly every visible wavelength. It should be noted that these colors might also be attributable to diffraction processes caused by minute cracks in the window glass. Photo taken on November 15, 2012. See also the Earth Science Picture of the Day for December 16, 2012.
Photo details: Camera Model: Canon EOS 40D; Lens: EF100mm f/2.8 Macro USM; Filter: CPF; Focal Length: 100mm; Focus Distance: 0.56m; Aperture: f/3.5; Exposure Time: 0.017 s (1/60); ISO equiv: 800; Software: Adobe Photoshop CS5.1 Windows.