Chris L Peterson wrote:

Turn off the tracking and make a star trail image. I've never done this,
with any mount, and not seen wiggle in the trails.

Of course you are right. But I have never done that, period. I'm not
inclined to swap cameras between 'scopes just now, but at my first
opportunity I will put a DSLR on the longer FL 'scope (150/1100mm refr.
vs. 106/530mm refr.), up the image scale a bit to exaggerate the
effect, and make an exposure or two with the drive turned off. I'll
post a link here. We'll see if I benefit comes from a 1600 lb pier
base, a relatively short 7" steel pier, and a semi-rural environment.
OK, we won't really see that, because I'm not going to move it all
someplace else for a comparison....

Davoud

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm