Steve's Atmospheric Optics
Crepuscular rays are parallel cloud shadows. Perspective effects make the light that peeks through the shadows appear to
eminate from the solar point. Anticrepuscular rays again are parallel cloud shadows that streak across the sky to the opposite
horizon and appear to eminate from the anti-solar direction.
Here's an example of crepuscular rays. One shaft of light is reflecting from a pool of water.
Here's an example of anticrepuscular rays looking directly opposite the setting sun. This was an incredible sight.
Here's an example of the geometry that creates crespuscular visuals. These are 1000-yr old primodial redwoods of the Muir Forest.
They are about 250-ft tall, and grow almost perfectly parallel to one another. Point the camera up, and the parallel trees look
like crepuscular rays.
During a flight, the jet contrail produced a shadow onto the clouds with a hint of a glory at the antisolar point (left). Once
we got below the cloud deck, a very nice anti-crepuscular display materialized (right).