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Missed the GRS
AA Subject: Missed the GRS
AA From: Anonymous AtWork AA Date: Wed, 28 Jun 2006 12:35:19 -0400 AA AA In this order? In that case, it must be thermal non-equilibrium. I AA bring it out, use it and put it away all within an hour or so. Definitely let the scope acclimate to the outdoor tempeature, specially if there is a sensible change of tempeartue between the storage place and the yard. This means if the house is ACed or the garage is sunbaked, you got to put the scope out early in evening, like at sunset, to let it cool, or heat!, to the ambient temperature by nightfall. AA You should check your collimation (and optics) by doing a star test (use AA Polaris). This will allow you to precisely align your primary, assuming AA that everything else is right on, i.e. focuser square, secondary properly AA positioned/rotated, secondary pointing at center of primary. A 6" f/8 can AA be off quite a bit and give ok views, but for great views must be pretty AA much right on. If you made the mirror I suspect that it might not be great, AA but I certainly don't know that. The star test will tell you what is going AA on. See, for starters: AA http://aberrator.astronomy.net/html/...r-testing.html AA AA I bought the mirror, so that should be OK. From the link: AA AA "If you see a perfect round airy-disc surrounded by concentric well AA defined rings your scope is definitely collimated." AA AA I definitely have not seen that, so I may not be collimated. Unless the air is steady, or the scope is stabilized, and you got good eeyesight, you won't see the ideal Airy disc image. That's why you got the suggestion to collimate with defocused images. AA As far as the GRS goes, it will not look red, or anything like it, but more AA like a hole in the band. Join your local astro club, and compare your views AA to what others are getting. AA AA The local astro club is quite a ways from where I live, but I may have AA to resort to that. The meeting place or postal address may be a bit far away. There could be members of that club closer to you whom you can all or email for assistance. How far is far? That is relative. In Monttana, if the club is farther than what you'll drive to attend a swinger's parrty, that's too far. In New York, if you have to take more than two buses/trains to get to the club, that's too far. --- þ RoseReader 2.52á P005004 ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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