Some guiding light - Forums

Topic starter

Apr 13, 2021

I’m looking for some guidance on guiding…. I have a C925 and am using a DSLR (full frame Canon 5D Mark IV), generally with the Celestron .7x reducer, and I’m read y to add auto-guiding to my set-up. It sounds like an OAG is the way to go with my scope and the person I spoke with at OPT recommended the ZWO OAG with the 120 or 190 camera. Reviews for the ZWO OAG are mixed, though, and for the most part even the most positive reviews say it does the job inexpensively, but has its pain points – principally, a poor quality mirror stalk and an awkward focusing arrangement. So, I’m wondering what others have experienced and any alternatives I should be considering. Unfortunately, simple availability may also play into my decision. I can be fairly patient, but the scope I ordered in November and finally gave up on 4 months later to take a chance on Ebay instead, is still on backorder…..as with all other out of stock astronomy gear, I assume.

Thanks!
Scott

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Steven

Apr 13, 2021 · Edited: Apr 13, 2021

I have the ZWO AOG, and I'm pretty satisfied with it. The Setup is a bit fiddly. And yea.. the focussing can be a bit of a mess.
As you have to basically unscrew the camera and slide it up or down the stalk in order to get focus and then tighten down the screw again.. which might move the camera ever so slightly again, losing focus.. Best tip I've seen in reviews, set it up during the day as much as possible. this helps a lot..
(focus the scope/camera first.. and the AOG after.

And ever since I've had it set up, I haven't really had to touch it anymore other than some finetuning .. since my rig is pretty much "permanent".. I keep everything connected to the scope.

Either way, even without picture perfect focus, you're able to guide just fine. Not sure about the quality of the mirror stalk, I'm not an expert on the thing, so I wouldn't know about that. Again, bit fiddly to set up. But again I haven't touched it ever I got it all working.

I do know that ZWO also offers a "1,25" helical focuser" which fits the 120 mini or 290 mini camera. That should help with the focusing, that does ad some cost to it all. But I have the normal 120 camera (not the mini), so the helical focuser isn't an option for me, but again.. I've managed just fine without it so far, even if it is a bit fiddly.

I wouldn't know about alternative AOG, as this is my first AOG.. there might be far better ones out there.. also not sure if you need/have other requirements with your focal length. I'm only using it on a 400mm.

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Scott Badger

Topic starter

Apr 14, 2021

Thanks Steven, I really appreciate your feedback! I’m also looking at the QHY Med which has a helical focuser if anyone has experience with that one. Sounds like backfocus may be something to sort out as well, but every discussion on it quickly makes my head spin….

Cheers,
Scott

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Wim van Berlo

Apr 14, 2021

Zwo oag with helical focuser+ asi290 mini works for me. Without the focuser, it’s fiddly.