by Dave Mitsky
In this afocal picture of Mercury on 2006/2/21 using my Canon EOS Digital Rebel DSLR camera, the stock 18-55mm Canon EF-S lens, a 40mm University Optics MK-70 eyepiece, and the 17" f/15 classical Cassegrain at the Astronomical Society of Harrisburg's Naylor Observatory near Lewisberry, Pennsylvania. The colorful effects of atmospheric prismatic dispersion were clearly visible as Mercury began to set.