Off Axis guiding

[m.tweedy]

I am considering buying an Atik OAG to go onto my 460EX and EFW2 (Astrodon6nm narrowband and Astronomik LRGB) to be used mainly on my WO GT81 not reduced (i need to get some basic imaging before contending with reducers and spacers). I am intending to attempt longer exposures hence guiding.

Is it practical to guide with an OAG on such a short FL scope or should i use a seperate guider. i have a Lodestar x2 mono

[davedownsouth]

You probably want someone with more experience to give you the correct answer, but I used the Atik GP OAG built into my Atik One 6 (Basically a 460) for guiding with my WO Star 71 and that worked very well for me.  Will be interested to hear if this set up is not appropriate for some reason 

[swag72]

I use an OAG on my short focal length scope at 330mm but only because I have a camera with it all integrated and if it's there I will use it.

Recently I was using a camera without a built in OAG and using my finder guider to do the work. I could find no difference in the guiding figures and overall guiding accuracy. You should be absolutely fine not using an OAG at a short focal length. I'm certainly not saying it's WRONG, but it's not necessary, unlike when you get to the long focal lengths.

That's my take on it anyway, having used a 330mm with and without an OAG

[m.tweedy]

I use an OAG on my short focal length scope at 330mm but only because I have a camera with it all integrated and if it's there I will use it.

Recently I was using a camera without a built in OAG and using my finder guider to do the work. I could find no difference in the guiding figures and overall guiding accuracy. You should be absolutely fine not using an OAG at a short focal length. I'm certainly not saying it's WRONG, but it's not necessary, unlike when you get to the long focal lengths.

That's my take on it anyway, having used a 330mm with and without an OAG

Thank you Sara I rate your opinion very highly indeed. I think i may well leave OAG for the moment until I have some experience under my belt (then OAG on my C8 or C11 for small planetary  ).

[tony210]

I was blown away by my OAG but using a mirror scope 8inch RCT where mirror movements are likely. With a refractor if you have a well bolted down guide scope you should get a very  good result- but OAG is great! - Tony