Equinox, 2018

A time lapse video of March 20, 2018 - the shadow mark travels along a straight line, right down Route 66. Shot frames every 30 seconds for the whole day.

  Audio, with full respect, by Pink Floyd, The Dark Side of the Moon, 1973 

A fairly typical data collection day, August 21, 2017. This was the day of the major US Solar eclipse, but unfortunately the morning was quite cloudy in Albuquerque. I chose to record each 15 minutes on the 21st of each month. 

A full Moon gives the same effect as the Sun, only fainter. If the moment of full Moon happens during the night the time readings are actually very close to accurate! I shot a frame every 30 seconds, at ISO 800 and f = 3.1 with shutter open for 13 seconds to capture enough light. This was taken the night of August 25-26, 2018, when the Moon reached full at 4:56 am. If done in winter the shadow length will be much longer. 

Audio by Cat Stevens, Moonshadow from 'Teaser and the Firecat', 1971.