Page 2 of 2

Posted: Tue Aug 11, 2009 5:20 pm
by rlow
The 10" was good but with no tracking not so much fun for planets or small DSO's like planetary nebulae. I would imagine that with the light pollution large DSO's are out of the question anyway.. what's the use of unused aperture right? :-)
Welcome Orly. My Mom is from Manila, so we have something in common.

My 11" f/5 dob can be easily hand-tracked at 200-300x. I have also managed to hand-track the Ring Nebula at 686x on Andrew's 15" Obsession. So, with a properly built dob mount with smooth motions, I believe your 10" f/5 mirror can be put to good use. I am building some dobs here, you can check it out next time when its done.

We have observed many DSOs through a 10" scope here in Singapore despite the light pollution. For a better view of DSOs, some of us drive 100km into Malaysia on a monthly basis.
One other possibility (I'm all over the place!) is the Vixen BT-70. I used to want the Fujinon 10x70 FMT-SX but realized that without 45- or 90-degree eyepieces your neck will eventually kill you. Downside of the BT-70 is it can't do high mag very well, and with light pollution planets are your friend :-)
You probably mean the Vixen BT-80MA (you can do a search here to view the photos), which I have used from 25x to 90x magnification. For planetary observations with both eyes, I would prefer a premium scope with bino-viewer.

Posted: Tue Aug 11, 2009 5:44 pm
by orly_andico
hi Richard,

that's the key.. good mechanicals are a must on a dob. Mine did not have these (I just ordered ebony star a year ago for the Nth rebuild... which never happened).

also my 10" mirror is a Guan Sheng, not a Royce or anything like that.

regarding the BT-70 (there is such a thing now... cheaper than the BT-80MA) I was thinking more of use for low powers. It's not very good for much over 90X due to the difficulty of maintaining collimation.

I'm really leaning toward an ETX-125 or Nexstar 5. It costs 1/2 of a 10" Royce mirror :-)

It should be apparent from my leanings that my budget is around the $700 - $800 (USD) range. Since buying a scope in SG is hopeless, I'm planning to have it sent to the Philippines and hand-carry it on my next trip to Manila. US-PH shipping is cheap because of VPost-like services due to the large Filipino expatriate community in the US.

Posted: Tue Aug 11, 2009 7:12 pm
by weixing
Hi,
orly_andico wrote: also my 10" mirror is a Guan Sheng, not a Royce or anything like that.
IMHO, Guan Sheng mirror is not that bad la... and you don't need a Royce mirror to blow most (if not all) 5" scope out of water... what a 10" mirror had regardless of brand (as long as it's a decent mirror), is raw light gathering power and resolution. :mrgreen:

Good luck in your telescope purchase.

Have a nice day.

Posted: Tue Aug 11, 2009 7:24 pm
by orly_andico
Thanks for the advice. :-)

Perhaps I will keep the 10" mirror for now. I was trolling in Digi-Key and found this 1 RPM DC motor for $75 SGD. I think I will retrofit that to my EQ-1 clone and try to do some astrophotography. The EQ-1 clone has horrific PE but am thinking of just using a 200mm lens, 15-second exposures, and stacking like crazy.

There's some software now that can even correct for field rotation..

Posted: Wed Aug 12, 2009 11:40 am
by rlow
regarding the BT-70 (there is such a thing now... cheaper than the BT-80MA) I was thinking more of use for low powers. It's not very good for much over 90X due to the difficulty of maintaining collimation.
I think you mean Orion BT70 which has been around for a while, which in your earlier post you stated as "Vixen" BT70, which Vixen does not have. The quality of the Orion BT70 is not on par with the Vixen BT80MA.