Meade OAG / PHD2 Queries

[Peter_D]

Hi,

I am setting up my Celestron C6 for DSO imaging. I know it's not ideal scope but I want to see my results before having to possibly part with it. There's no rush as I still have to get a 0.63 reducer - this is all just practice, getting used to the equipment I have and seeing what I need to purchase over the next while. 

Progress: Day 1: I was able to focus the  guidecam attached to OAG  and DSLR during daytime and later connected to PHD2 successfully. No guiding. Polar alignment off.

Day 2: Polar aligned better but had taken off the guidecam after the session and had to try focusing on a star moving the guide camera up and down. The star wasn't precisely focused and although PHD2 started guiding (yeah!) it lost the star pretty soon.

The OAG I use is a Meade Off Axis Guider that I picked up a few months ago. I have a couple of questions on it specifically:

1. Do people usually have a dedicated guide camera attached to the OAG that they set up once in the daytime and just keep it screwed in at the correct height for focus? It just doesn't seem like it is precise enough to do the focusing during night time if you have taken off the guidecam before -  my guidecam is currently my asi224mc (my planetary cam) so I might need to get a dedicated asi120mc mini if I stick with the OAG?

2. The Meade OAG just seems badly designed to use with a DSLR.  You can see in the photo that you cannot fully attach the camera without the body of the camera or the OAG thumbscrew  coming into contact. Frustrating. To I need an extension or a locking ring? A better OAG?

3. Last question (sorry if it is basic) - Do you set up the guidecam first in, for example, Sharcap and then shut Sharpcap down and start PHD2 or can the setup of the guidecam be done in Sharpcap and we keep it open and then start PHD2? I'm confused.

Thanks for any guidance (pardon the pun!). It would be great to see if anyone else is using this type of OAG and can shed a little light on question 3.

Final thought, would it be just easier to use a 50mm guidescope? 🙂

Clear skies

Peter

[michael8554]

Hi Peter

1.  Use a Parfocal Ring to set how far in the guidecam is inserted for best focus. I'm assuming your ASI224MC has a 1.25" nosepiece attached.

Yes, keep the guidecam in place if possible, once you have best focus.

2. That fouling will occur with most OAG's. You need to mount the DSLR inverted, so that the flash housing doesn't foul.

Loosen the three tiny screws that hold the EOS bayonet in the T2 adapter, rotate, retighten.

3. Setting the guidecam focus is a one-time operation if you keep it in place.

Then at the start of each session, focus the DSLR, then the guidecam should be in focus too.

So routinely no need for SharpCap, unless you use it for PA.

Michael

 

[Peter_D]

That's super Michael, many thanks for the detailed explanation!