Re: [APML]: What a difference alignment makes

[ipper@juno.com (C B IPPER)]

On Fri, 18 Oct 1996 13:03:44 -0700 aa6g@aa6g.org (Chuck Vaughn) writes:
>
>>        This is a note of profound thanks to Chuck Vaughn. May you 
>have a
>>million clear and starry nights! I got your clear concise 
>instructions and
>>tried them out last night.
>
>It's my pleasure! This is a good time to mention the importance of the
>"5 minut rule" of drifting. Some recent experiences by a friend of 
>mine with
>drift alignement has driven home the importance of making sure the 
>star does
>not drift at all for 5 minutes if you expect to do long exposures with 
>no
>field rotation. Even a couple of arcseconds of drift is too much if 
>you plan
>to do 2 or 3 hour exposures. It's a good idea to use an illuminated 
>eyepiece
>and bisect a star with one of the lines. It should not drift above or 
>below
>for 5 minutes. You may find it necessary to make adjustments as small 
>as
>10-30 arcseconds in azimuth and altitude to achieve this.
>
>I added a short paragraph to my Drift Alignment article to emphasize 
>this.
>
>Chuck Vaughn   <aa6g@aa6g.org>
>
>
>
Hi Chuck,
   I do the same kind of drifting too, however for more accuracy and
speed, I would add to your instructions:
I use a 2X barlow  on the illumunated eyepiece, checking everything twice
and a final check for twenty minutes, in each direction.
James  Foster showed me this years ago, and it work well using a C-14  @ 
f/11    It can take a couple of hours, facilitating long exposers... Carl
Faulkner.