Sponsored By:

Subject: Re: CCD imaging in Atl/Az mode
From: Jason Ware
Reply To: mapug@shore.net
Date: Wed Dec 28 07:47:50 1994

> From owner-lx200-l@netcom.com Fri Dec 23 16:42:29 1994
> From: TybeeE@aol.com
> Date: Fri, 23 Dec 1994 16:44:34 -0500
> To: lx200-l@netcom.com
> Subject: Re: CCD imaging in Atl/Az mode
> Sender: owner-lx200-l@netcom.com
> Content-Length: 273
>
> Has anyone ever done any CCD work with an LX200 in the Alt/Az mode? I read in
> one of Meade’s ads that for exposures longer than approx 5 min field rotation
> comes into play, but was wondering about exposures less than 5 min. Has
> anyone tried it
>
> TybeeE@aol.com
>
> Tybee Evans
>

Depends where you are in the sky. The 16" gives a readout on the amount of field rotation. It sometimes shows 0 for 10-15 minutes while tracking on an object. This might be a good feature for all lx-200s in the future. People could use use this to see low long of an exposure they could make.

I would guess you could get away with a couple of minutes on a ccd. However, YOU HAVE TO GUIDE. Most of the errors people are blaming on field rotation are actually drift. Even the LX200 cannot go for more than a few seconds without a small amount of drift. This small drift will show up in a CCD image.

remember that you can have up to an arcminute of periodic error in each axis. You can PEC train out the RA (AZ) but not the DEC(ALT). Buy an off-axis guider!

Jason Ware