130305

130305 Telescope Workshop notes, March 5, 2013
Attendees: TomK, EdK, JerryW, TomT, DmitriiZ, TimC

TK- While waiting for 220grit for his big mirror polishing, he has 4.25” glass blank to make a solar dobsonian (for projection image for kids) grinding against another blank. TK asking JerryW about wedge angle on back to avoid extra 4-5% coming back on top of the front of the uncoated polished mirror. Sky &Telescope magazine may have info on making these. Or he might make it into a planetary scope. Jerry says power of scope could be up to 50-60X the primary inch size.
TC – showing three page “First Scope for Astronomy-What’s Best?” document. TK suggests sharing on Google Docs. Correction needed for refractor diagram. Doing more review, looking for glossary to define jargon. People start with eyes on constellations, then add binoculars. TT asked about apochromatic, and JW explained. TK suggested short refractors being handy for Firstt telescope. TC- side story, Nagler made TeleVue telescope to test his wide field eyepieces.
DZ,TK- say to TC, go to Google.com, log in, use docs.google.com. TC wants to make a poster for Astro Day of Tscope recommendation stuff. TC will email to TK. TK-going to science night at Vieja Valley and other with mirrors. Wants to help finish doc.

TK- Find book from Willmann-Bell (www.willbell.com) about telescope issues. [lots of books on making telescopes, WOW!]
JW- Sky & Telescope has Ipad app for seeing how your telescope would see an object.
JW- Also app for predicting Jupiter's moons and red spot.http://www.skyandtelescope.com/community/skyblog/newsblog/Take-a-Tour-of-Jupiter-with-Our-Newest-App-182423791.html

TK- Orion Highlight plossel eyepiece with Orion ED80 for about $800, can see Mag 9 stuff, instead of Costco $200 stuff, so people can appreciate night sky.
JW- When glass batches change, manufacturers generally come up with new name/type for their telescope due to the glass change.
Dmitrii- polishing 12.5” with Cerium Oxide solution. JW says it is a colloidal solution.
TT asking JW about focal length on Celestron SCT C8. Secondary mirror is convex, acting as a magnifier of perhaps 5X. Set up C8 Primary mirror at highest magnification, leave it there and use external fine focuser at 2” threaded end.
JW- Scope City (Thousand Oaks) out of business, do not use website, may lose money.
DZ- mentioned SBHackerSpace group looking for physical space to work in. so possible to combine with that group for permanent spot. Locker to hold mirror that is being worked on? Fyi: DZ- co-founder Eucalyptus.com cloud computing stuff. http://sbhackerspace.com/
Stellafane table for grinding mirrors. TC- 55gal drum with water does not go anywhere!
See http://stellafane.org/tm/atm/index.html

JW- Russel Porter telescope donated to museum, stored somewhere. [base got lost, after it had been discovered at Bob Graves house.] http://www.sbau.org/newsletter/September2009.pdf
Photos: http://www.flickr.com/photos/27241501@N03/sets/72157632971487703/