For those interested see http://www.socastrosci.org/images/SAS_Vol_10_3.pdf Jeff Hopkins Phoenix Observatory (187283) Counting Photons Phoenix, Arizona USA www.hposoft.com/Astro/astro.html http://www.hposoft.com/SB/SpectroBook.html 2012 ASP Amateur Achievement Award -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.