Re: [APML]: Is this too difficult for me? Opinions please..

["Derek Stuart O Keeffe" <okeeffed@csnovell.ucc.ie>]

Olle,

I built a mount for telephoto lenses a while ago. I used an old 24 
hour timer for the drive. and guided with a 60mm refractor.
The best it could do was 20min with 200mm lens and it was 
very difficult to keep it guiding accurately this long.

You will definetly have to guide with a 400mm lens.
I would advise you to get a small refractor to guide with.

Derek.

> 
> I have just started in astrophotography, which the photos on my homepage,
> make very clear. Now, I am in the middle of building an equatorial motor
> driven mount for my camera. I intend to use it both with short and long
> lenses.
> 
> I would like some opinions on weather I should adapt the mount to work best
> with short lenses or the 400 mm lens I have. The mount will not be guided in
> any way and doing a perfect polar allignement could also be a litle
> diffcult. The lens itself is rather heavy and the mount is not particularly
> rigid.
> 
> Will I be able to use the 400 lens or is the chance of failing to big to
> take on such a task? Opinions from anyone are most welcome.
> 
> 
> Olle Eriksson
> 
> PS. I have updated my homepage with two new images, one panorama from Orion
> to Pegasus and one of Auriga. So far, all I use is a tripod and a cable
> release.  More images will come the next several days.
> 
> http://w1.116.telia.com/~11600278/photos.htm
> 
> Homepage at http://hem1.passagen.se/astrosci/
> 
> 
>