Re: [APML]: Beginner Needing Advise

[RLECKER@aol.com]

In a message dated 96-09-24 15:12:36 EDT, you write:

<< And remember, the advise given on this list by people who know is to never
go much 
 over 5 secs for a guidance exposure due to atmospheric perturbances
introduced into the image. >>

Steve,
     I guide on 10th mag. stars on balmy nights in the desert with less than
a five second exposure, this varies to the size of your guide scope,  the
larger scope will need less exposure time.  I use a 4" guide scope and a
friend uses a 5".  The 5" needs a ND filter to guide on any thing less than
7th mag.  The limiting mag. of the Pictor 201 xt is about 12th mag. and some
that have been twique are getting 13 mag.  Now you are getting to the limit
of my 10" scope of visible mag. of the scope.  This makes it almost
impossible to even find a good star to guide on and impossible throught a off
- axis guider.  Ask anyone using a electronic guider what mag. stars are best
to guide on??   I like the 8th mag. because they are easy to find in my 4"
scope and the exposure time is short ( about 2/10 th of a sec.).   I
photograph all night long using the Pictor and sleep while I'm taking
pictures.  The SBIG guys are getting the same results, no better, no
worse..................you want some pictures see Dan Cheng homepage (I hope
he doesn't mind) http://www.commasoft.com/dan

ric