"mike ring" wrote in message
. 1.4...
"Chris Taylor" wrote in
news
Shouldn't you mount it on an eq wedge for long exposures, as although the
altaz mount cant hold position, it slowly twists relative to the universe
if running relative to the earth
Hi Mike
Field rotation isn 't really an issue so long as its not prevalent in any
one frame. The stacking software I use takes care of the rotation whan
aligning by using two stars against which to align.
The tracking errors of the goto mount move the image more than a few pixels
over about 15 to 20 seconds causing star trails. My LX90 is good for about
30 to 60 secs without field rotation (depending where you aim) and a few
minutes when polar aligned.
Regards
Chris