Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Ian on Aug 19, 2010, 19:14:26

Title: Off Axis Guider or Guidescope
Post by: Ian on Aug 19, 2010, 19:14:26
for about a ton, I can either buy an OAG or a side by side bar.

Question is, which is the best option if I only go for one?

Assume I have something like a QHY5 and an ED80 :)
Title: Re: Off Axis Guider or Guidescope
Post by: Rocket Pooch on Aug 19, 2010, 19:26:15
OAG I don't use my bar any more, and only one dew strip, one scope etc.
Title: Re: Off Axis Guider or Guidescope
Post by: Mike on Aug 19, 2010, 20:11:05
I would agree with that. I find I get better results piggybacking than using a bar personally.
Title: Re: Off Axis Guider or Guidescope
Post by: Ian on Aug 19, 2010, 23:17:52
was wondering how easy it is to find a bright enough guide star. Do you have to do much searching and re-framing Chris?

Like the avatar by the way. Looks like a DSC project suggestion.
Title: Re: Off Axis Guider or Guidescope
Post by: Rocket Pooch on Aug 20, 2010, 07:06:22
since i got the qhy6 i have not had to find a guide star a 1 second exposure gets me a mag 18 guide star and there are a few of them about, also i use AA and it finds a guide star only 100adu above the background noise.
Title: Re: Off Axis Guider or Guidescope
Post by: RobertM on Aug 20, 2010, 10:40:56
Ian,

I would add that if you're using a field flattener/reducer where back focus distance is limited then you'll need to check that the required spacing can still be achieved.  If it can then you'll need the right spacers to make up the distance.

Another option is a second hand 50mm finderscope converted to a guider with the QHY6.  That would be very light weight and could sit on your scope rings.

Whatever you do I'd suggest avoiding a side by side bar if you can.

Hope that helps
Robert

Title: Re: Off Axis Guider or Guidescope
Post by: Ian on Aug 20, 2010, 14:58:02
Now that's a thought robert... hmm, I hope google will be able to cope with the load...
Title: Re: Off Axis Guider or Guidescope
Post by: MarkS on Aug 20, 2010, 15:09:58
Quote from: Ian
Now that's a thought robert... hmm, I hope google will be able to cope with the load...

Google?
Title: Re: Off Axis Guider or Guidescope
Post by: Ian on Aug 20, 2010, 15:23:16
Google guiding tm

Nope, just googling for options, costs results etc.

Although I've established that it's cheaper to download a hubble image and call it my own. I don't think anyone else has considered doing that...
Title: Re: Off Axis Guider or Guidescope
Post by: Rocket Pooch on Aug 20, 2010, 16:57:15
Fay did it.
Title: Re: Off Axis Guider or Guidescope
Post by: Ian on Aug 20, 2010, 17:00:30
Chris, you've clearly been on the bench too long.   :cheesy:
Title: Re: Off Axis Guider or Guidescope
Post by: The Thing on Aug 20, 2010, 20:26:03
I did the 50mm finderscope/guidescope thing with my QHY5. Very successful as my LX90 tracks much better with less excess weight. Just ask PHD to select a guide star...
Quote from: Duncan on Jul 03, 2010, 14:10:26