Please Recommend a Guiding Scope

[AdamJL]

Hi folks

Please can you recommend me a guide-scope. Open to all suggestions under my max budget which is $500. Doesn't mean I want to spend that, but can be convinced if the argument's good enough :rofl:

My current equipment is below in my signature; I'm shooting 600mm f/l only for now, with a plan to upgrade in the next 12-18 months to a 900mm f/l OTA so I'd like the scope to match that.

I will also be getting a ZWO ASI290MM Mini camera, if that helps.

Cheers!

[billdan]

I used the Orion 50mm f3.2 mini guide-scope ($160 from Bintel) for a year attached to my 8inch F5 Newt. It worked great, plenty of guide stars to choose, never had an issue with it, but it does fog up in humid weather.

I was getting around 1arcsec RMS guiding with it on an EQ6, I later replaced it with the Orion thin OAG and got 0.7arcsec RMS guiding. When I replaced the EQ6 with a Mesu 200 mount, I got 0.4arcsec RMS guiding.

OAG's are a pain to setup (took me 2 hours) mainly because I dropped the prism and installed it back to front.
Guide stars are easy to find using an OAG on Milky Way targets, finding a guide star when imaging a remote galaxy can be an issue though.

[multiweb]

For the cost and reliability you can't beat an OAG. Off course it's a pain to set up and get the guider in focus the first time but it's a one of and then it's done. The benefits far outweigh potential issues especially flexure. You can also check your focus while imaging by looking at your guider's stars. win-win.

[The_bluester]

My SVX80 worked well with a guidescope, and pretty well with the inbuilt guider on my mount, but I don't reckon I would want to try it with anything less solidly mounted, or much over the 480mm focal length. The inbuilt guider guides down to about 0.8" on decent nights, I don't think it is reasonable to expect much better out of a 120mm focal length guider.

I use an OAG on my C925 and it guides down to about 0.6" on my old Orion Atlas. I bought the QSY OAG-M as I had rigidity issues with the Orion thin OAG I used before where the QSY is much more solidly constructed. With the ASI290MM mini camera I have never actually had an issue finding a guide star though there have been times PHD2 has picked about the only star I could see in the field.

[AdamJL]

I should have mentioned I'm not looking at a OAG setup currently. In future, sure, but I've got enough to learn without adding something new.

[multiweb]

Actually an OAG is likely the way you'll end up going in the end, it's cheaper and more reliable. Some things are worth learning right at the beginning then you're done with it all for the better.

[Zuts]

For long focal length imaging OAG is the way to go, however if you do go with a guide scope then the longer FL the better for longer FL imaging scopes.

I have a Baader Vario finder which doubles as my guidescope. It's well made has a 60 mm objective and a FL of 250 mm. The focuser is only a drawtube which is not really suitable however it can be locked into place at the rough focus and a zwo helical focuser added for fine focusing.

You can also take widefield images through it.

[AdamJL]

thank you! This seems to be the path I'll follow. Thanks for the specific model to look into.

[Startrek]

I started imaging just over 3 years ago using an Orion 50mm guide scope in the offset shoe of my newt, worked ok
Then advanced to an Orion 60mm guide scope with helical focuser piggyback mounted on a dovetail bar central axis on my newts
So much easier to achieve focus on PHD2 using the star profile tool , also has a wider field than the 50mm and there a larger selection of guide stars
(Orion 60mm guide scope with helical focuser has a focal length of 240mm)

[Startrek]

Forgot to mention I’ve used a ZWOASI120MM-S ( USB3 ) guide camera from the start , great guide camera !!

[AdamJL]

Update.. I got my new setup yesterday!

50ED Evostar + ASI290MM Mini.

I chose the 290 in case I want to get into OAG in the future as it's more sensitive.

Happy days! I set everything up in Nina and will hopefully try a test session tomorrow night for a couple of hours.