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

[cvedeler@bio2.edu (Chris Vedeler)]

The Astro-Photography Mailing List
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At 02:53 PM 7/27/98 -0400, you wrote:
<snip>
.  I tried several
>different eyepieces, but was unable to find one in my case that
>was parfocal with the ST4 -- any hints as to what you were using,
>Chris?  

Gil, I just happened to have an eyepiece which was very close to parfocal to
the ST-4.  It is the 10mm eyepiece that came with my Orion Short Tube
refractor.  It's not perfect but with a little electrical tape to make the
eyepiece sit about 1/16th of an inch out from it's normal place, it is
pretty darn close.  It is a really cheap eyepiece, so if Orion sells them
seperatly I can't imagine it is more than $30.

>
>Up until this time, I have been guiding manually.  My experiences
>with the LX50 mirror those of others that have posted here.
>The periodic error of the LX50 is fairly large, >30 arcseconds,
>but occurs mainly in two areas of the worm period.  

The periodic error with my LX200 is at least 30 arcseconds almost all of
which is to the West.  But with PEC it's probably less than 5 arc seconds
(boy am I glad I got the LX200 instead of the LX50.).

Chris Vedeler
http://www.isomedia.com/homes/cvedeler/space.htm
Tucson, AZ