GEM for an XT10

Hi everyone,

I currently own an Orion XT10 dobson (10 inch F/4.7). I'm looking for an
equatorial mount for this scope to do some serious longtime exposure
photography. Can someone give me some examples of mounts that will be
suitable for this job? The option to add a goto system is preferable.

Joe

Joe Peterson wrote:

Hi everyone,

I currently own an Orion XT10 dobson (10 inch F/4.7). I'm looking for an
equatorial mount for this scope to do some serious longtime exposure
photography. Can someone give me some examples of mounts that will be
suitable for this job? The option to add a goto system is preferable.


Joe,

There a number of options in this area. But you should be aware that for
Astrophotography the mount is the most critical piece of equipment. So
with that being said.

1) Bisque Millenium

2) Mountain Instruments MI-750, MI-500, MI-250

3) Astrophysics AP-1200, AP-900

4) Losmandy Titan, G-11

5) Older Byers mounts

6) Parks or Cave Mounts


This is not an all inclusive list and it should be noted that the bottom
end of each manufacturers mounts will likely be marginal with a 253mm
f/5 scope plus all the mountain paraphenalia and imaging equipment. Not
impossible mind you. Just more prone to wind problems. The first four of
these are either Go-To or it can be added. Now I am not certain what you
mean by *serious* but to me this means capable of handling exposures of
60 minutes or more. If you would like some empirical data I regularly
image with a multitude of 253mm OTA's. Ranging from f/4 through f/15 and
the optical payload with cameras and dovetails and mounting rings at the
like is around 50 to 75 pounds. The mounts best suited (in my opinion)
for this type of loading are the Bisque, MI-750, AP-1200 and Losmandy
Titan. If you can accept some compromises the G-11 *may* work. But with
mine I have a lower incidence of success than with a larger, more robust
mount. None of these are cheap. The cheapest starts at around $3,000
while the upper edge is over $10,000. Second-hand equipment might be
preferable for you. Beware of going too cheap though. Certain mounts
having the weight handling capabilities have unacceptable tracking
(periodic error) and can lead to much frustration.

Astrophotography is a serious illness that costs thousands of dollas.
Beware ! :^)

Regards

BIll

Celestron CI 700 should work. You'll need to fab a short pier for it.
You can also get it with advanced Astro Master.

John

Joe Peterson wrote:

Hi everyone,

I currently own an Orion XT10 dobson (10 inch F/4.7). I'm looking for an
equatorial mount for this scope to do some serious longtime exposure
photography. Can someone give me some examples of mounts that will be
suitable for this job? The option to add a goto system is preferable.

Joe

"John Kulczycki" wrote in message
...
Celestron CI 700 should work. You'll need to fab a short pier for it. You
can also get it with advanced Astro Master.

I used just such a combination with reasonably good results
with a Parks 10" F/6 optical tube. This scope weighed
even more than the intended scope. While not perfect,
I was able to get well tracked autoguided exposures of
up to 20 minutes duration with a Starlight Xpress MX916
CCD and Star2000 interface. While these mounts are no
longer made, they are available used, and show up from
time to time on AstroMart.

Thanks, Tom Davis