12 Aug
2003
12 Aug
'03
8:47 p.m.
--- Josephine Grahn <bsi@xmission.com> wrote:
Perhaps once or twice in six years that we've tried, has the seeing been good enough to tweak the collimation of our 16" scope at adequately high power; and never good enough for the 24".
Jo, try stopping-down the aperture. It won't affect the accuracy of the collimation job, and will allow a star-test on a night not good enough to support a huge aperture at high magnifications. This will have the secondary benefit of increasing the obstruction in relation to the aperture, making the diffraction rings even easier to see. C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com