On June 30, 2010, an NS SD40E helper set (rebuilt from SD50s) drifts down at Summerhill, Pennsylvania. These signals are easily accessible. By design, position light signals are meant to be viewed head on, which makes it difficult to capture their aspects in photographs in bright daylight. Canon 7D with 28-135mm lens set a 70mm, ISO200 f/5.0 1/800.