FRESNEL LENS, SPLIT ROCK LIGHTHOUSE, SILVER BAY, MINNESOTA, JULY 1, 2015
Pentax 18-135 at 28mm
1/160 sec. f10
Deborah Abbott, sprightlier than I am, climbed the long winding staircase inside the historical lighthouse at Split Rock on Minnesota's Lake Superior north shore to capture this view of the mighty Third Order Fresnel lens from the landing below. Although the lighthouse was retired in 1969 and has become a museum, the lens remains on its pedestal and emits a beam every November 10 to mark the loss of the lake freighter Edmund Fitzgerald in 1975.