The problem with equatorial tables is that the two axis are not orthogonal.
So you are going to have a tough time with guiding. Additionaly, with CCD
shots, you'll want to shoot the object of interest for 3 or 4 hours, so
pushing the table back, reaquiring the object, and resuming your shooting
can be a pain.
You should consider the objects that you are going to photograph before
purchasing a large scope and mount. The most interesting objects are most
easily photographed with instruments in the 4" to 14" aperture and 900 to
1300 mm focal length ranges.
Once you get down to objects less than 4 arcminutes wide, the detail is not
generally there to make a photograph that is interesting. (Unless you are
doing research for supernovae or minor planets).
Michelle
http://www.plettstone.com/telescopes
> -----Original Message-----
> From: sf-bay-tac-bounces@No-Spam [mailto:sf-bay-tac-bounces@No-Spam]On
> Behalf Of Leonard Tramiel
> Sent: Monday, July 14, 2003 11:50 PM
> To: The Astronomy Connection
> Subject: Re: [TAC] Big Dobs on EQ mounts
>
>
> The equatorial tracking platforms do NOT produce field rotation. An alt-az
> drive that is driven in both axes will cause field rotation but the
> equatorial platforms don't.
>
> I don't know how well the set-up will work for photography but at
> least one
> of the eq platforms has an available dec motor and accepts ST-4 autoguider
> input. See:
> http://www.johnsonian.com
> I just bought one of these. I didn't get the dec motor and I'm
> not planning
> on doing astrophotography
>
> -Leonard
>
> ----- Original Message -----
> From: "Tony Hurtado" <tony-hurtado@No-Spam>
> To: "TAC" <sf-bay-tac@No-Spam>
> Sent: Monday, July 14, 2003 5:40 PM
> Subject: [TAC] Big Dobs on EQ mounts
>
>
> (I saw something like 80 minutes for one model, but that's not
> really a big
> limitation, is it? Also, there is a field rotation issue.)
>