Astromart

June 25, 2010 08:40 AM Forum: Beginning Astronomy?

MN56 or M6511 or 4 1/2" refractor?

I once did some side-by-side comparisons of a 4" APO and a 6" F/12
Mak-Cass on planets. The views were pretty similar, except the
Mak-Cass took a very long time to cool-down and equal the APO.
So given your interests and choices, my vote would be for something
like the 120 ED.

Between a 120 ED refractor and MN56, my vote would again be for
the refractor. The MN56 central obstruction will decrease planetary
resolution slightly, and mirrors (typical coatings) will give
slightly dimmer images. And again there are some cool-down
issues with the MN. If you were looking at a 6" or 7" MN
then I might reconsider.

July 12, 2010 02:27 AM Forum: CCD Imaging and Processing/Solar System

Jupiter 11 July 2010

Posted By John Biretta

Superb detail!!!! C14?

July 15, 2010 05:51 PM Forum: CCD Imaging and Processing/Deep Sky

2nd image TEC 140

Posted By John Biretta

Very, very nice!! Congrats!!

July 20, 2010 05:23 PM Forum: Equipment Talk

"C14 is a Small Scope" (The Movie)

Posted By John Biretta

Great stuff!!

Here is an even eassier (for me) method which only requires lifting
the scope to about waist level:

(1) Get a table and place it right next to the mount. I use
a Rollatable. Some attention may be needed to the height of
the table -- I slide some long 2" PVC pipe (about 36" long)
over the table legs to get a few extra inches of table height.

(2) Place C14 on its side on the table.

(3) Tip up C14 so it is facing front end down, and resting
on the front end.

(4) Make the Dec axis horizontal.

(5) Move the C14 over to the mount and attach to the saddle.
I use a Cassady tip-in saddle.

(6) Add counter weights one at a time to the Dec. axis
until the C14 is lifted off the table. You are letting the
mount + counter weights do the heavy lifting.

(7) Move table away. You are done.

This has worked very well for me. It feels well controlled
and no back straining.

July 22, 2010 02:31 PM Forum: CCD Imaging and Processing/Solar System