For anything closer than infinity, you need to be able to rack the eyepiece out. Put your shortest focal length eyepiece in the focuser, then back it out just a bit to be safe. Your longer focal length eyepieces should work just fine as long as you have enough travel in your focuser. Wayne A. Sumner Math/Physics/Astronomy/Engineering Boy's Tennis Coach Northridge High School Davis School District (801) 402-8610
Mark Shelton 04/28/11 4:31 PM >>> Hello all, I am just getting ready to cut my trusses for the dob I am making. The question I have is where to make the eyepieces I have come into focus. I have read that you use a 2" eyepiece racked all the way in and cut your trusses when it just reaches focus. Then I ready just the opposite. You should cut your trusses so everything is in focus with your eyepiece racked all the way out.
What are your feelings on the matter. I feel I should make eyepieces come into focus in the middle of the travel of the focus-er. ?????? Thanks for your help in this matter. Mark Shelton _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
When I built my two Newtonians I allowed one inch of travel from minimum to the point where my shortest focal length eyepiece (7mm at that time) came into focus. I've never had problems with any other eyepiece, and this with a low-profile focuser. Kim _____ From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Wayne Sumner Sent: Thursday, April 28, 2011 5:00 PM To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Dob Help? For anything closer than infinity, you need to be able to rack the eyepiece out. Put your shortest focal length eyepiece in the focuser, then back it out just a bit to be safe. Your longer focal length eyepieces should work just fine as long as you have enough travel in your focuser. Wayne A. Sumner Math/Physics/Astronomy/Engineering Boy's Tennis Coach Northridge High School Davis School District (801) 402-8610
Mark Shelton 04/28/11 4:31 PM >>> Hello all, I am just getting ready to cut my trusses for the dob I am making. The question I have is where to make the eyepieces I have come into focus. I have read that you use a 2" eyepiece racked all the way in and cut your trusses when it just reaches focus. Then I ready just the opposite. You should cut your trusses so everything is in focus with your eyepiece racked all the way out.
What are your feelings on the matter. I feel I should make eyepieces come into focus in the middle of the travel of the focus-er. ?????? Thanks for your help in this matter. Mark Shelton _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1321 / Virus Database: 1500/3602 - Release Date: 04/28/11 _____ No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1321 / Virus Database: 1500/3602 - Release Date: 04/28/11
participants (2)
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Kim Hyatt -
Wayne Sumner