From: Mark Gaffney <markgaffney@mac.com>

Date: July 8, 2008 6:34:33 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] A couple of questions...

Hi Milton, I`ve emailed Celestron Support about the possibility of moving the mirror up the tube. Nothing is mentioned about this proceedure in the manual though so I don`t hold any great hopes. It usually takes Celestron 2-3 days to respond in my experience. The Baader filter is $110 at My Astro Shop plus around $10 for Express post which they usually use (gets your purchase to you in a day or so). Buying things from America may be relatively cheap on the face of it but postage is very prohibitive. I priced the postage for the parts for the Unibrain camera & it`s $55 usd on top of the $22.50 usd cost of parts! There`s an extra charge for currency differences as well.... Also, your proceedure for achieving focus may seem second nature to you but I`m experiencing no such simplicity! This is with the C10-NGT & stars anyway. The 4SE is another kettle of fish. (Both have a 1.25" eyepiece incidentally, the C10-NGT has the 2" option also). I`m in a Catch 22 situation where I can`t use the camera properly & Astro IIDC`s excellent facilities to align, yet because of alignment am having difficulty sighting objects! I figure if I break the circle by obtaining the manual reticle & drift aligning that way I can obtain the Baader filter in 2 weeks time. Last time out I didn`t adjust the polar alignment hoping it`d be in much the same position (not physically moved) & only did a 2 star alignment. So I guess it`s no wonder the star was unsteady in the FOV. I didn`t get out & attempt the re-location of the nosepiece etc. in the holder as it was so damn cold this morning! Will have a go some time soon though. My best moon shot taken with the C10-NGT so far, is part of the photos section on the Yahoo site so you can see I`m in no difficulty with it. Mark.

On 09/07/2008, at 6:38 AM, Milton Aupperle wrote:

Hi Mark;

On 8-Jul-08, at 1:17 PM, Mark Gaffney wrote:

Hi Milton, The focuser is an idea for the future if I find I need more inward focus. I`ve approached Moonlite about the base plate. I`d be using the "Display Reticle Overlay" option if I could obtain any image of a star at all through the C10-NGT. I think the star in question is staying still long enough to get a fix on it but I can`t see any image anywhere in the focuser`s travel. Unless I`ve got the exposure quotient a long way off? I`m yet to try Tim`s suggestion to adjust the play in the nosepiece/eyepiece sleeve before buying an extender tube due to unsuitable weather so far. The extender tube I`m looking at is only $35 anyway! Mark

Well $35 is nearly 1/2 the amount of a Baader UV/IR cut filter and if you don't need the extender, then why buy it?

For Focus, I find that if I put an eyepiece in, achieve focus, center the star, remove the eyepiece and then attach the camera (assuming the 1.25" - Cmount is normal design),  it's usually pretty close. And even if it's not, I then use high gains and say 533 ms exposures until I see the defocussed "donut" star and then adjust focus form there. But if the star is streaking across the FOV because of poor alignment or motor / speed issues, well it may be gone by the time you do the switch.

TTYL..

Milton J. Aupperle