CG-5 question

Hi all,

I am considering purchasing one of the new CG-5 Advanced Series mounts for use with my 5" Mak, and my 8" f/5 Newtonian. I'm pretty confident that the CG-5 is plenty adequate for the 5", but what about the 8" Newt? It's probably 18 - 20 lbs with rings, finder, and eyepiece. Does anyone here have a similar setup? What is your overall impression when it comes to vibration and dampening? How
about digital camera photography on planets? Is the 8" too much? Thank you for any input or thoughts on alternative mounts.

Regards,

Matthew Sherman
NGC ME!

Hi Matt -

The CG-5 can handle an shorter 8" newtonian. I use this setup all the time for mainly planetary and some deep sky imaging. My OTA is an 8" f/5.

That being said, it is not the ideal setup for imaging. If it is too breezy it vibrates enough that I cannot image. Dampening time is around 3-4 seconds after focusing. On mine, I am still trying to find if the source of vibration is in the mount itself, or flexure in the legs where they connect to the mount. I actually am suspect of the latter, since it seems to vibrate in a direction consistent with leg connection. The new tubular steel legs on the CG-5 most likely address this problem nicely.

The next step up from the CG-5 would be the EQ-6, which would be a very stable setup with an 8" newt. The downside is that most reports of the EQ-6 mount are that it has pretty large periodic error, which would make it a less desirable choice for imaging.

Beyond that, you start getting into the ideal mounts for imaging with an 8", mainly which are made by Losmandy. They are very expensive, and worth it if you are doing serious astrophotography and long exposures.

For me, the CG-5 has been fine, since I only do casual CCD imaging (i.e. shorter exposures).

Hope that is helpful.

-Jake