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Re: [APML] ST4 Guiding Advice



How often are the large errors and on what axis (R.A. or Dec).  What are your brightness readings?  If you are getting consistent A2's and A3's and then sudden A8's or higher you may be hitting bad portions of the worm, barring any bumps of the mount or wind gusts.  When I use the ST-4 I like to keep the EA around 1 sec and adjust the B and BA.  Only as a last resort do I adjust the EA any higher.  My advice is to run some tests using a brighter star and keep the integrations short, see what it does, then run tests with longer exp, i.e. 5 sec.  A sudden bad spot during a 5 sec exposure can send the star out of the guiding box.  As for the film in the camera, only developement will tell.  A bad focus will also give you erratic readings on the ST-4.  If you are guiding at a focal length close to or longer than the scope you're shooting through then you may not have very large trails, if any at all.  Any shot no matter how bad isn't a wasted shot, as long as you learn something from it.
 
Daniel
http://home.earthlink.net/~dreyna14/astro.htm
----- Original Message -----
To: APML
Sent: Friday, June 14, 2002 4:00 PM
Subject: [APML] ST4 Guiding Advice

 
I've just started "playing" with my "new" seconhand ST4 and msu admit it appears a bit
intimidating.
 
I've read several articles on the www about guiding with the ST4 and looking at most APMLer's photo's, they (you)
seem to get guiding errors of A2 or A3.
 
I'm getting fluctuating readings from A2, A3 then a jump to A8, A9 or AE.
 
I'm using a 80mm F9 refractor for guiding, and have tried turning the Scintillation "off" (setting 8), and use
an exposure of about 5 seconds with a Brightness Adjust of 2 or 3.
 
I was under the impression that with the results I'm getting (A8's etc.) the picture would be ruined (the film is still in the
camera) but looking at pictures recently uploaded by Steve Lindsey, maybe not. If you look at his pictures (he reported
getting A8's, AE's on some pictures) they're really good (by my standard).
 
Does this mean my film (still in camera) is not totally wasted and what can I do to get better guiding results.
 
Thanks for any advice
 
Eddie Guscott