Re: [APML]: LX-50-astrophotography? & ST-4 test first night

[apilato <apilato@spectra.net>]

The Astro-Photography Mailing List
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Chris V.,

> PS:  Take a look at one of my first attmepts at real CCD imaging with >my ST-7.  It's a 
>8 minute exposure of M17.  Any ideas what the black >centers are in some of those stars? 
> I'm guessing the focus was a little >off.

You are correct. The "Donuts" are due to poor focus (you are seeing the
Main Mirror and the hole in it). Unfortunately, I have been there many
times before. After focusing and slewing or moving certain 'scopes, the
Main Mirror flops around and throws the image out of focus. I have
learned to re-focus before any imaging is started.

Tony P.
Binghamton, NY
apilato@spectra.net
http://www.spectra.net/~apilato/astro.htm