AutoGuiding for Refractor & SCT

[Tim99]

I am ready to take the AutoGuider plunge. I would like to buy a system that I could use on both my 80mm Refractor and my Edge HD 9.25 SCT. Is there a way to do this? Right now, I am using the refractor for imaging DSO's but I would also like to use the SCT sometimes and switch the guide system over.

Do you do this or is this a dumb idea?

I am looking at the Orion StarShoot AutoGuider Pro & 60mm Guide Scope Package. Is this a good package for using on either the Refractor or SCT?

Any help is appreciated.

Tim

[Davey-T]

I used to swop my SSAG between refractor and SCT with no prob's until I got a OAG then had to get more sensitive Loadstar,

One big drawback ATM is that Orion haven't bothered to get off their butts and make it work with Win 10.

Dave

[Tim99]

Thanks Dave.  Won't work with Windows 10 eh?  I plan to use PhD on my Windows 10 machine.  Are you saying their camera won't work or their software or ... ???  New to this.  Could you explain?

Thanks, Tim

[Davey-T]

Just that Orion haven't come up with camera drivers for Windows 10 so it won't work full stop, don't know why as there must be thousands in use, it can hardly have come as a surprise to them, hardly rocket science to write a driver  

Dave

[ollypenrice]

So far as I know there is no reducer for the 9.25 Edge so it really is going to take some guiding. I'd be wanting an OAG. As above, you'll need a sensitive guide cam for that. I'll also say, are you dead sure you want to try DS imaging at the pixel scale of a DSLR in an unreduced 9.25? Is this going to work? Hmmm, not too sure about that, being honest. The Canon in your sig would give 0.45" per pixel. That would be right on the limit for our very competent Mesu 200. That guides at about half an arcsecond of error. I say this because if it isn't going to work there are easier ways to guide the refractor.

Olly

[Davey-T]

Focal reducer for 9.25 Edge, not cheap

Dave

http://optecinc.com/astronomy/catalog/lepus/index.htm

[michael8554]

Murphy's Law applies here.

Your 2.4M focal length means those tiny nebulae are nicely framed.

But it's F10 so you will need long exposures.

And long exposures plus long focal length equals epic quality of guiding.

Maybe lots of shorter exposures will work for you.

Also I'm quite happy with results that Olly would not find acceptable,  maybe just do the best you can with what you've got?

Michael

[ollypenrice]

Murphy's Law applies here.

Your 2.4M focal length means those tiny nebulae are nicely framed.

But it's F10 so you will need long exposures.

And long exposures plus long focal length equals epic quality of guiding.

Maybe lots of shorter exposures will work for you.

Also I'm quite happy with results that Olly would not find acceptable,  maybe just do the best you can with what you've got?

Michael

Yes, perfectly valid but how much more do you invest in what you've got? I invested far too much in assuming I'd be able to image with my 10 inch LX200. I never did get to image with it. I had it, I invested more in it and that investment was wasted. I don't suggest that this would always be the case and it's quite possible that someone else might have done better than I did - but I post this thought because it's based on my own experience.

Olly

[Tim99]

Thanks for the discussion fellas.  I bought the SCT with the idea that I would use it for planetary work.  Had read about using webcam and stacking and thought that sounded fun.  

The little 80mm Refractor is what I have been using for DSO imaging so far.  That has been very enjoyable.  I understand that the long focal length of the SCT makes it difficult to use for long exposures.   I thought with a good guide system, I could give it a try.

I have a saying, "A little knowledge is a dangerous thing."  This certainly true in this hobby.  A person can spend a lot of money foolishly if he isn't careful.  lol

[Tim99]

Thanks Olly for your candid response.  I tried to image Andromeda Galaxy when I first got the SCT.  Results were not good compared to what I was getting with the 80mm Refractor.  This verified what I had been reading about trying to Image at f10.

Reading your explanation and as I learn more, the question is why pour money into trying to image DSO's at f10 when success can be achieved so much easier with my little Refractor?

I decided to enjoy DSO imaging with the ED80 and leave the SCT for visual (observing) and maybe give Planetary imaging a try.  I like what i have read about the ZWO ASI224.  Sounds like I might get good planetary images with that cam on the SCT.  Could I also use that cam for auto guiding on the 80mm Refractor?  What scope would you suggest I use for guiding on the 80mm Refractor?

Thanks,

Tim

[derrickf]

,

the question is why pour money into trying to image DSO's at f10 when success can be achieved so much easier with my little Refractor?

The answer to your question lies in what you are trying to achieve:

your small, short focal length refractor will enable you to take widefield, relatively low resolution images of most objects. Take NGC1514  as an example - an 80mm refractor can produce a pleasing, widefield view of the object in a large starfield, however you will not resolve fine detail in the structure of the object because you are imaging at a somewhat coarse image scale. See  this post for a representative example (72mm scope)  http://stargazerslounge.com/topic/256612-planetary-nebulae-ngc1514pk-205-the-medusa-nebulae/?hl=ngc1514

A longer focal length instrument (my 12" f/8 and your 9 1/2" f/10 are similar in focal length although yours is slightly slower) will have a greater image scale and resolve greater detail at the cost of both increased exposure times required and a mount that is capable of accurate guiding at this focal length. See my poor attempt a few years ago here: http://dfarley.co.uk/Latest_Images/NGC1514.htm

HTH

Derrick