From: Mark Gaffney <markgaffney@mac.com>
Date: September 25, 2008 3:46:23 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] calculating in arc seconds etc....
Thanks Jeff for all of that info provided in the link. I went first to CcdCalc & another site providing basic info but quickly found they would only open on a Windows computer! The widget I found was basically useful. I`m still having troubles with Polar Alignment, which is a pain in the neck down here in Australia. I got a fairly good alignment a while ago but soon shifted the C10-NGT & never quite retrieved it. This alignment was done using Iterative Polar Alignment (I chanced upon Sigma Octans it seems!) as it`s nondescript & easily mis-identified. I`ve tried some drift aligning with an Illuminated Reticle eyepiece but found that only gave me roughly the right position (perhaps I should have persisted a good bit more). I find I do things like fumble the wrong button on the HC & have to start again from the beginning or lose contact with the cigarette lighter attachment by shifting the battery pack, with the same result! I sometimes try to avoid the long electrical cord.Then there`s dew! I`ve ordered a hair dryer but it hasn`t come yet! The new scope (C9.25XLT OTA) is great otherwise! Mark.
On 26/09/2008, at 4:15 AM, Jeff Phillips wrote:
Lots of useful stuff here:
http://www.wilmslowastro.com/software/formulae.htm
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On Sep 25, 2008, at 12:15 PM, Mark Gaffney wrote:
Hi, does anyone know of a link to an online calculator for details involving given scope &
CCD...image scale, FOV,resolution etc. Preferably one that lists TIS & PGR cameras? Mark.