Attendees: TomT, JerryW, TimC, EdK, JoeD, ChrisU, DavidH
JoeD brought in 6” AstroTech f/4 that he is modifying for portability: http://www.buytelescopes.com/astro-tech-6-f4-imaging-newtonian-optical-tube . He moved the focuser position farther out since he will not be using a camera. He has made a perpendicular plywood mount with three hand holds and swivel bottom on a heavy duty photographic tripod (Manfrotto). The mount can also stand flat on a table with its slippery feet to allow horizontal movement without a tripod. First light with the new mount was tonight looking at the Moon and Jupiter and its moons. Some diffraction on objects, possibly from large secondary mirror, that Joe says was used to make the telescope more useful for astrophotography. Also, Joe will try to reduce some wobble of the tripod mount and the bottom plate attachments.
TomT mentioned that summer meetings pushed by JerryW will be attempted, hopefully members will do them, which was also suggested by Jerry. We can have outsiders come in as well, and the backup is to use videos taken off YouTube or astronomy DVD programs.
TimC did a little more 320 Al2O3 grit grinding on the 8” donated mirror. JerryW checked the surface with the loupe and called it good. Tim will try to find some 500 grit, Aluminum Oxide.
EdK brought in mirror, but no testing setup tonight. Ed will be modifying his polishing stroke to chordal to remove the turned down edge.
DavidH’s old Celestron German Equatorial Mount that fell off table last week and bent a wormgear shaft, already has been fixed by Art Harris.
TimC-will be writing another article for newsletter, talking about steps of understanding telescope functions, but wants help from JerryW and TomW final editing. Tim wants to get around to describing the earliest telescopes and history of telescopes.JerryW-says think of Power as diameter increase, 100X means Jupiter would look 100X bigger than what the human eye can see alone. He discussed apparent field of view (field stop edge in the back of the eyepiece) vs. field of view thru the telescope, which depends on focal length of telescope divided by eyepiece focal length.
More photos of tonight's session: http://www.flickr.com/photos/27241501@N03/sets/72157639851024855/
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