(Tony Flanders) wrote in
:

(Chris.B) wrote in message
. com...

I very occasionally use a large & very heavy double-legged Bogen
#3047 tripod with its own pan-tilt head for my 90mm f/11 Vixen
refractor. Putting it as mildly as possible: It's a complete
disaster at any power!

Of course that doesn't work well! But there is a world of
difference between a 90mm F/11 scope and an 80mm F/5 scope. I used
to use my Televue Ranger (70mm F/6.9) atop Bogen 3011 and 3021S
legs with the 3026 video head, and it worked like a charm. I still
do that from time to time, but now I mostly use my Unistar Light
head atop the same tripods, which works even better.

The only problem with the photo-tripod/video-head combination is
that it is a little hard to track at high powers (over 100X),
especially near the zenith.

I have used the ST-80 on a Bogen 3130 head without any particular
problems, as long as the magnification is sensible in context. Of
course, a video head is better, in that it offers easier pointing. As
Tony points out, an 80mm f/5 is a rather manageable scope.

Note that the Bogen combination mentioned above probably costs
more than the AZ-3 mount, so cost is *not* one of the benefits.
The major benefit is dramatically improved portability. But if
you don't plan to cart the scope around, there's little reason
not to get a full-fledged astro mount.

Part of the motivation is that I have a spare set of tripod legs. While
the eventual application is not likely to involve much carrying around,
the parts will get "carted" to India in my luggage, in a couple of
months. Portability is at least an incidental issue. Also, keeping in
mind that Indian homes are smaller than US ones, the mount needs to
support multiple uses if possible, hence an incentive to put the mount
on the photographic tripod legs. Further, as tony presumably knows quite
well, portability is a different class of problem in India, where cars
are small and transportation is generally more of a pain.

- Shankar