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View Full Version here: : Decision time: OAG or GS


Alkor88
11-08-2018, 09:49 PM
Good Evening,
I want to push the capabilities of my setup a bit further. Guiding is on the cards.
I have my doubts about OAG with a 9.25 SCT. Especially having the standard tube and not the HD (flatter field). Guiding scope seems a better option.
Cheaper too because I already own an ORION 80mm short tube scope (FL400/F5) with CG-5 bracket.
The other thing on my mind is downsizing the scope. My NexStar is for sale.
So I have to get a new tube for my CGX. I thought to step up to the Celestron 9.25HD but after reading a lot about AP I might go for a smaller refractor like the SW Esprit 100 or 120
I am sort of torn between two ideas.
May start with a cheap ASI120 to see how it all works.
Any guidance?

StuTodd
11-08-2018, 10:14 PM
There is no reason you can't use an OAG with the C9.25. The set up may cost as you may require an f6.3 focal reducer and a sensitive guiding camera.

If you already own an 80mm scope and bracket, go for that option. Both have pros and cons but the guide scope option is probably the easiest for learning imaging with.

Alkor88
12-08-2018, 05:19 PM
I actually might give OAG a go. I am testing PWI 1.2.1 tonight and also have now PHD2 installed. It sees the mount through PWI.
Need to get the Celestron off-axis adaptor, wide adaptor for it and CCD camera.
I'll use the Canon 6D as main camera for the time being.

So what is a sensitive camera for OAG? Will the ASI120MC do or does it need to be better? ASI290MC?

StuTodd
12-08-2018, 08:21 PM
The camera needs to be sensitive to get a guide star in such a small area that the pickoff mirror yields. The 120 would be good but have you considered the mono version rather than the OSC?

doppler
12-08-2018, 08:53 PM
Hi Peter, I have the 120mc and while it is great to use with a guide scope it does struggle with the OAG at times, I think that the 120 mono would be a lot more sensitive and a better starting point.

Alkor88
16-08-2018, 03:00 PM
Thanks Rick,
I did so a couple of days ago. The 120mm-s is already in my hands and I am testing it first as a prime focus cam to get the hang of it. Those little things are a lot more fiddly than my Canon.
I was thinking of using it when aligning the mount with PWI but that is difficult because to FOV is so narrow.
Peter

multiweb
16-08-2018, 03:06 PM
With an SCT, OAG all the way.