Moonlight Reflection off a Lake

November 08, 2012

EspelhodeAgua-LuaeJupiter-net (2)

Photographer: Miguel Claro 
Summary Author: Miguel Claro; Dave Lynch, Jim Foster

The photo above showing the waning, gibbous Moon and a moonlit landscape was taken from Juromenha, Portugal, in the Alqueva´s Dark Sky Reserve. This reserve was the world's first starlight tourism destination. The bright light of the Moon all but conceals a nearby celestial object that's easily revealed by looking at the lake. How much light is reflected off water’s surface depends on the angle of incidence and on the plane of polarization. Light loss due to polarization will definitely dim the reflections. This photo is at a zenith angle of 70 degrees, so polarization is significant but not as strong as it could be -- polarization is maximized at an incidence angle of approximately 53 degrees known as Brewster's angle. In addition, the lunar aureole is helping to hide Jupiter. The aureole will also be dimmed by reflection/polarization and so helps explain why Jupiter can be seen in the reflected light. Note that the star to the upper right of the Moon is Aldebaran, in the constellation of Taurus the Bull. Photo taken a little past midnight on October 6, 2012.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 50D; Lens: 10-20mm; Image Date: 2012-10-06 00:26:44 +0000; Focal Length: 10mm; Aperture: f/4.0; Exposure Time: 30.000 s; ISO equiv: 1000; Exposure Bias: none; Metering Mode: Center Weight; Exposure: Manual; Exposure Mode: Manual; White Balance: Manual; Flash Fired: No (enforced); Orientation: Normal; Color Space: Adobe RGB (1998); Software: Adobe Photoshop CS6 (Windows).