Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Equipment Discussions >> Reflectors Previous   Index   Next   Threaded   Pages: 1 chefdrew sage Reged: 03/02/08 Posts: 427 Loc: Marietta, GA Holy cow, my XT10 is out of collimation       #2623769 - 09/04/08 03:03 PM Edit   Reply   Quote Quick Reply   Ok well it's not as bad as it seems but to you guys it might be. I have only had the scope for about 1 year and comparing the views against other scopes it produces great views. I have been using the collimation cap alone to do the collimation on the scope and although it looked good apparently it was OFF. I could still split the double-double with it and I figure well if I can do that and it looks pretty well collimated through the "cap" I must be doing a fine job with it I just received a Cheshire Newt. collimator in the mail today and when I started the collimation process I noticed that the secondary wasn't even set low enough to be perfectly centered in front of the eyepiece So some months ago when Mars was high in the sky I was wondering why I couldn’t get it to focus properly, it looked like it had a ghost shadow (sometimes 2 of them) and maybe some of you veterans can clarify this for me but I am guessing that collimating my scope with the secondary set high would be the cause of it Well I am guessing that the views through the Newly Collimated XT10 should be a bit more crisp from here on out, but I wont be able to really compare it to the views of Mars until next year. Edited by Don W (09/04/08 05:07 PM) Post Extras:       Jason D Carpal Tunnel Reged: 10/21/06 Posts: 1960 Loc: California Re: Holy cow, my XT10 is out of collimation [Re: chefdrew]       #2623860 - 09/04/08 03:55 PM Edit   Reply   Quote Quick Reply   Assuming your axial collimation is good (focuser + optical axes coincide) then centering the mirror does not impact the crispness of your image. Not unless it is way off to the point where you start vignetting the primary. In this case, you start reducing your aperture which translates to resolution reduction. I do not believe this was the case for you since XT10 comes with an oversized secondary. I am afraid the double image of Mars can't be explained by miss-centering the secondary. Jason Edited by Don W (09/04/08 05:08 PM) Post Extras:       veebs2 sage Reged: 03/13/07 Posts: 206 Loc: DeKalb, IL Re: Holy cow, my XT10 is out of collimation [Re: chefdrew]       #2623922 - 09/04/08 04:23 PM Edit   Reply   Quote Quick Reply   I think you will be very happy with properly collimating your scope. I used a Orion site tube/chesire combo tool for a year and thought I was close until I got my Glatter laser. It turns out my secondary was not centered using the 1 1/4" site tube...now with the 2" holographic laser I am positive the secondary is centered and everything is aligned. I had the best views in my scope this past weekend. Let us know if you see a difference the next time out! Edited by Don W (09/04/08 05:08 PM) Post Extras:       rickertk sage Reged: 06/14/07 Posts: 221 Loc: Outer Philadelphia suburbs Re: Holy cow, my XT10 is out of collimation [Re: veebs2]       #2624486 - 09/04/08 09:26 PM Edit   Reply   Quote Quick Reply   To amplify on what the others have said - an off-center secondary won't affect the crispness of the image (and my XT8 was off-center to start with, but gave a good star test). What it does affect is the evenness of edge illumination - the center of the field will be fine, but some of the edge will be darker than it should be. Keith -------------------- Oberwerk 11x56 Orion 8XTi Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 11 registered and 10 anonymous users are browsing this forum. 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