[APML] Focusing an ST-4

["Emmanuele Sordini" <vega@bloomingstars.com>]

Hi everybody,
having acquired an ST-4 recently, I was trying to reach proper focusing it 
with my different scopes. I'm faced with the following problems: 

1) I am doing some trials from a small terrace in a building downtown quite 
a big city, from which the north pole is not visible.
2) I wanted to use my "downtown trials" to get all my rig up and running, so 
as to not waste my time when in the field under good skies. 

Problem #1 is a pain in the butt since mine is not a permanent setup, and 
whatever chosen star is chosen always drifts out of the field of view very 
very quickly. So, focusing by the only means of the ST4's brightess readout 
is very difficult and doing a drift alignment can take quite a considerable 
time.
Thinking about alternative ways of nailing good and consistent focus, I was 
wondering if the following could work: 

1) Focusing onto an artificial bright object (such as a street lamp or an 
artificial star) lying far enough away (HOW far away is another matter). No 
more ages spent aligning, putting together and taking apart the whole 
equipment.
2) Focusing with a PC. Trouble is, the ST-4 is not a webcam so one can't 
have a continuous, real-time flow of frames. Perhaps, a hartmann mask could 
be of some help here, and the software used could make a big difference as 
well. 

Anybody have any suggestions/tips on the above? Are those ideas sensible or 
should I just take the pain of squandering a whole observing night on good, 
ol' techniques? 

Thanks in advance,
Emmanuele Sordini 

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo