Recommendations for guide scope for C11

Considering C11 Edge in next year or so. Would appreciate your input on what would be a good affordable guidescope package? I would be using it on a DX mount and Canon XSi camera at first. I have a SPC900NC and Neximage5 that might be used for autoguiding, but can purchase a new cam if necessary. Thanks for any ideas, experiences, suggestions.

With an SCT, you will want an OAG.

For a DSLR, I'd suggest one of the thin OAG's and a very sensitive guide camera like the Lodestar or Lodestar v2.

Like this, Adam?

http://www.highpoint...-guider-atk0070

Hi,

I have seen people using a guidescope on the Edge 11" with no problems of flexure. Wouldn't a scope with a lode star be ideal vice the OAG?

I don't have experience with the ATIK. I did like my TS9-OAG, but it's very similar to the Orion thin OAG that is out now for less money. Bear in mind, I don't have experience with it specifically. I'll hope an owner chimes in. The reason I like the thin OAG's is it allows you to maintain the back-focus with all stock Celestron parts.

OAG's are more difficult to get setup then guidescopes. You must get both cameras parafocal. If you go with a camera like the Lodestar, SBIG or QHY5LII, they have 1.25" bodies and you will need a c-mount to 1.25" compression ring so you can slide the guide camera up and down to focus. As well, you NEED a sensitive camera, I tried and tried and tried. I bought the Lodestar, and success!

I used to use my guidescope as a guider for my 8" SCT. I was able to get 8m subs, but after that they showed drift. Many people may have success with guidescopes, but with an SCT's moving mirror I think the OAG is better. Not necessarily because the mirror is the cause of the issues, but because when battling elongated stars, it's not always obvious what's causing them. You can buy more rigid mountings and upgrade your guidescopes focuser, but even then, an OAG is guiding at the full FL of the system. It's more accurate, and gives sharper stars.

Are you looking at the C11 primarily for imaging, or for visual? Mainly asking because I think one of the most difficult factors in guiding that rig will be the long 2800mm focal length, which will magnify errors… it's a tough place to start out in autoguiding. You might consider the f/7 adapter, which takes it down just under 2000mm, but I don't know if that leaves enough room for an OAG if you wanted to go that route.

For a guidescope, Stellarvue makes a nice 50mm finder-style guidescope that isn't too expensive, with a good focuser, and a lot of attachment options. It's only about 210mm focal length, though, so you'd want to choose an auto guider with small pixels, maybe a QHY5L-II or a Starlight Xpress Superstar. If you go with a guidescope, try and attach everything pretty rigidly. With refractors, Astro Physics seems to have discovered that a major cause of flexure between scope and guidescope was the felt lining of scope rings or guidescope attachment feet. That probably holds for SCTs too, even though there are a couple of other factors as well, like potential mirror movement.

Good luck whichever way you go.

Woodworkt, I would like to eventually do imaging with the C11, but I have a C80ED I could begin with as I learn the basics. I'm in a fairly light polluted area so will require substantial filter use and processing.

You need a 300mm or so guidscope for that focal length to work. Orion makes a nice 80mm short tube refractor or you can buy a more expensive Baader setup from Astro-Physics. Also, get a focal reducer - that mount is going to be on the edge at 2800mm and you'll have a small field of view for any OAG to work with.

There's been an explosion in the availability of good quality guidescopes, and for some reason the trend in focal length seems to be right around 200-250mm as the sweet spot (averaging right around 225), even for those used/marketed to guide larger instruments.

Guidescopes, range from higher to lower fl:
--Borg 60 "miniborg": 60mm x f5.4 = ~325mm $$$
--Borg 50 "miniborg": 50mm x f5 = 250mm $$$
--Baader/Astro-Physics 61mm: 61mm x f4.1 = ~250mm $$$
--Stellarvue 60mm: 60mm x f3.75 = 225mm $$
--Stellarvue 50mm: 50mm x f4.2 = 210mm $
--William Optics M-G50: 50mm x f4 = 200mm $
--Astro-tech 50mm: 50mm x f3.6 = 180mm $
--Orion 50mm deluxe guider: 50mm x f3.2 = 162mm $

The only two I have personal experience with are the Baader/Astro-Physics and the Stellarvue 50. The Baader has a bit more aperture, 40mm more focal length, and a really great/rigid mounting bracket (at least if you get it through Astro-Physics, which makes the bracket)--it's the one I currently use. I found the Stellarvue to be substantially easier to focus, however, so it's the one with my wife's gear (it's also about half the cost). Craig Stark, the author of PHD, I believe also published an article that rates the Miniborg 50 very highly as well.

Hope that helps!

Woodworkt, I went to a totally different source: http://www.amazon.co...0332200_TE_item
This is a minimum weight and cost guide scope but should have the required FL for imaging. And, if it doesn't work out, one of my grandsons will get a nifty g & g.