11 August 2010
STAR TRAILS AT STUD HORSE POINT
For this post I thought I would share with you a different type of photography, star trail photography. This particular image was made in Utah a couple of years ago. It is an eight hour exposure that I made on film (you could do it on digital but you would need to be able to make sure the batteries did not die during the long exposure). The trails are formed as the stars paint light across the image while the shutter is left open. In the photo it appears as if the stars are rotating, in truth the earth is actually spinning beneath the stars. The brightest star near the center of the circles is the north star. The north star makes a very small circle because it is nearly over the North Pole (the axis on which the earth spins). If I were able to make this image in the far north during the period of 24 hour darkness, I could make a 24 hour exposure and the stars would make a complete circle.
The light you see on the rocks comes from a small sliver of moon that was up for a couple of hours during 8 hour the exposure.