Brad Wallis and Robert Provin, authors of "A Manual of Advanced Celestial Photography" have a comprehensive web site with lots of great images and links to their own web pages at:
Wallace & Provin page: http://geogdata.csun.edu/~voltaire/wallis_provin.html
Provin's home page: http://geogdata.csun.edu/~voltaire/
Wallace's home page: http://www.frazmtn.com/~bwallis/
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