Using a C11 at 7000mm of focal length, the 1.8 arcsecond disc of Ganymede is 11 pixels in diameter in my Webcam. That's large enough to show the partial phases of an eclipse by Jupiter's shadow. Here are 26 monochrome frames, each taken 30 seconds apart, and strung into an animation. http://www.pbase.com/polakis/image/147376394 Tom -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.