Re: [APML]: Fw: Guidescope advice sought

[Chuck Vaughn <aa6g@aa6g.org>]

Bill Franke wrote:
>  
>  I humbly disagree. I have taken exposures in excess of one hour using a
> guide scope and never (to date) had a problem of flexure. I grew weary of
> the exhausting effort in finding a guide star using an off-axis guider.
> Using a guide scope (with it's inherent freedom of choice) is a luxury I
> never want to give up. Perhaps the newtonian plays a part in your opinion?
> (I use a refractor)

Yes, it certainly does. A refractor guiding a refractor is the most likely
combination to work and people are using that successfully. That's
how I guide my camera lens. BTW, a camera lens is not less sensitive to
flexure than any other instrument. Flexure is simply how many microns
one instrument moves that the other one doesn't. 

Most people, including myself, have not been able to guide a newtonian
with a separate guidescope. I have a very long, frustrating and expensive
experience with that and I tried everything that three experienced
astrophotographers could think of over a year period. I needed three hour
exposures and I just couldn't do it.

I'm glad you're having success with your setup but that doesn't change my
advice to a beginner, especially those using SCTs or Newtonians. I think most
beginners want to have success right off the bat and an OAG will likely
do it for them. When they get some experience and want to try a separate
guidescope, then by all means give it a try.

Chuck <aa6g@aa6g.org>