PHOTOS: Rod McCullom
For some science slash aviation porn: Lensed a few images on Monday of the jet engine exhaust contrails from a 747. These are plumes of condensed water vapour crystallized by the extreme cold. It usually can be seen above 25,000 feet.
The images are lensed with a Canon SX30 in a modified AIRPLANE setting in AUTO. The focal length is 878mm.
The plane was traveling very fast and the contrails quickly dissipated. Obviously it's very difficult to get a clear and focused still image of an airplane at that height but here ya go. Not bad for 20-something thousand feet.