Hi Brian,

I think unfortunately the bad news is that you're going to need a tracking
mount. With webcams, your best images usually result between F20-F35.
That
means that at F6, you're going to need something like a 5x Powermate to
get
to F30. At this F ratio, planets move incredibly fast through the field
of
view and are nearly impossible to track manually. You can try, but I
think
you'll be disappointed.

You want to try to stick with 1/33 sec or greater with planets at
preferably
10 fps. Anything slower is prone to atmospheric smearing generally, and
anything faster is usually flooded with noise except on bright targets
like
the moon.

For your lack of motorized mount, you don't need anything special... just
something that "generally" tracks. With a dual drive corrector, you'll be
able to make up for any differences in planetary movements caused either
by
mount error or inadequate polar alignment. A good, decent cost mount for
you might be the Orion Atlas. It should easily handle your OTA and if you
watch the "2nd hand" portion of their website, you can sometimes find a
really good price. I found mine that way for under $650 a couple of years
back. It includes the polar alignment scope and dual axis corrector. I
know that might seem expensive, especially considering the price of your
Dob
to begin with, but you won't regret the upgrade.

You can always take images at either prime focus or, say, at F12 with a 2x
barlow, but these focal lengths are generally an inadequate "match" for a
webcam's CCD, which expects more than that. As a result, pictures lack
the
details they should have. Exceptions would be bright, large detailed
objects such as the moon and filtered sun, which will continue to reveal
detail at prime focus.

Good luck with whatever you decide.

Best,
John Anderson


Thanks John

I will keep my eye open for a mount. I currently enjoy the grab and go DOB
mount. I can be up and running in minutes from where I store the scope to
the deck. Add in cool down time of course.

I have uploaded a couple of the recent pictures onto
alt.binaries.pictures.astro.

Brian