Go to the above WEB site Scot Tuckers explanation for drift alignment is probably one of the best explanations on how to go about this. BTW I drift align at 300x and make adjustments until I have no drift for 10 to 15 minutes. It is not that difficult to do. And should be done every time. I even do it for piggy back with camera lenses. I use an AP 900 goto with my AP 6 inch F7 and I perform the same procedure with my 10 inch AP Mak. I should also note that my pointing accuracy with the 900 goto is dead nuts on when I drift align, not too shabby for a 5 year old mount!
Clear Skies
Dwight L Bogan
In a message dated 11/25/2003 6:03:50 PM US Mountain Standard Time, serge.theberge@wti.on.ca writes:
I have been told that for astrophotography, not only you must have a good,
sturdy mount, but you must have good polar alignment. I have seen various
rules of thumb about what is "good enough" polar alignment such as no
visible drift @ 200X for 5 minutes, others state 15 minutes, etc. My guess
is that there must be some kind of formula (or rule of thumb) linking
"maximum acceptable polar alignment error" to f-speed, magnification, film
grain size, exposure duration, etc. Can anyone enlighten me on this?
Thanks
Serge Theberge
Toronto Centre
RASC
> -----Original Message-----
> From: astro-photo-bounces@seds.org
> [mailto:astro-photo-bounces@seds.org] On Behalf Of Franklin A. Holub
> Sent: Monday, November 24, 2003 4:25 PM
> To: Discussion of Film Astrophotography
> Subject: Re: [APML]OT-Drift Alignment
>
>
> I haven't posted in a while but lets see if I can really mess
> things up... I'm going to make a statement that is going to
> fly in the face of years of experience and is going to
> contradict what we have always been told about drift alignment...
>
> But first, a little background...
>
> After a couple of years of being happy with "close enough"
> polar alignment, I installed a perminant pier and I figured
> it was time to "nail" my polar alignment. <snip>
|