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question about iOptron Sky Guider Pro

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Please help!

I have two of the iOptron mounts: Skyguider Pro and CEM40.

Still can’t properly guide despite precise polar alignment. My SGP mount, guiding in RA, seems to over correct, is that right? I keep getting the “Delta RMS threshold exceeded” error message.

How do you set to wide field guiding? I am using Orion mini scope on qhy 5-II-m for guiding my main scope Radian Raptor with focal length of 274 mm on Canon 60Da DSLR.
1 year 6 months ago #64541
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It looks like your guiding in RA is fine, with RA RMS = 1.39 in that screenshot. The total RMS is degrading, because deviations in DEC are increasing (DEC RMS = 4.27). That suggests that your polar alignment is off. How do you know that your polar alignment is precise?

Jo
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
1 year 6 months ago #64551

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Appreciate the insight.
You are probably correct. I do the polar alignment with the polar scope at the beginning of the session. What is your recommendation with respect to polar alignment just prior to guiding? Use the Stellarmate polar alignment or Sharp Cap routine? Look at Polaris again through the polariscope?
1 year 6 months ago #64557

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How do you know your polar scope is aligned properly? Have you tested whether the crosshairs are indeed centered on the RA axis?

You can do this indoors or outdoors for that matter during the day. Pick a point on a wall (like a dot on a piece of paper pinned to a wall or something similar, point the polar scope to it and then rotate the RA axis. If the crosshairs remain centered right on that dot, then your polar scope is aligned properly with the RA axis. If the crosshairs move away from that point, as you rotate the mount then you need to first align the polar scope, otherwise you will never be able to get accurate polar alignment.

Have you ever done that?

Jo
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
1 year 6 months ago #64558

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I am using the polar scope built into the RA axis of the iOptron mount. I am assuming iOptron has it's scope lined up the the RA axis correctly.
1 year 6 months ago #64559

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Adding to Jo's excellent questions, are you sure your telescope is in balance? Polar alignment certainly may explain the behavior you see, but unbalance as well.

Wouter
Wouter van Reeven

ASI6200MM and 7 slot 2" filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and 5 slot 1.25" filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
1 year 6 months ago #64561

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That is not at all a given. Aligning the polar scope does take some time and effort. It may be roughly aligned, but most likely not precisely. The other day I suggested to a member of my local club to check the alignment of the polar scope in his brand new iOptron CEM25P mount when he had similar problems. The polar scope was misaligned by 33 arc minutes!

You can test that also easily using the PA routine in Ekos.

The bottomline is it very much depends on who in the factory is doing that and how good and how fast they are. It makes little sense for iOptron to have someone spend 30 min to perfectly align the polar scope of a low end mount. That is not cost-effective.
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
Last edit: 1 year 6 months ago by Jose Corazon.
1 year 6 months ago #64562

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I did not realize how far off the Polar scope can be from the axis. Guess precise alignment would have to rely on Ekos alignment assistant or SharpCap. Which is better?

Thanks for the feedback on balance. Pretty sure I'm balanced with respect to the RA axis. Not sure about balance with respect to DEC axis, no guiding possible in this axis using iOptron Skyguider.
1 year 6 months ago #64566

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I would advise you to first check and then realign your polar scope. That's the way to quickly align if you are out in the field without a computer. That is the number 1 use for the SkyGuider Pro with a wide angle lens (up to 200 mm). It will take you about 30 min to fix that problem. Definitely do it.

Apart from that, the Ekos polar alignment routine is all I ever use. Never used SharpCap. So I would say, use Ekos and be done with one well functioning software suite.

Here the instruction for aligning the polar scope on the ZEQ25. The method for all other mounts should be pretty much the same.

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Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
Last edit: 1 year 6 months ago by Jose Corazon.
1 year 6 months ago #64569
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@ nanwang As you've seen to the other thread, I had exactly the same issue with like you with the internal guider. Bottom line: Nevered worked properly.
I gave up trying and loosing precious clear sky hours and tried with PHD2 (changed Ekos profile guider to PHD2 of course). Now the system works.

I am pretty confident that this has nothing to do with your PA. I used SharpCap and had excellent PA but never worked.

At the moment I PA only from polarscope and that helped me <strong>a lot</strong> on ditherting. Take a look here indilib.org/forum/astroberry/7997-dithering.html?start=0

For me works like this:

At PHD2 you have to set:
Dither settings: Mode, Random RA only, scale 4.0 (I use 4 combined with 4px from Ekos settings, so I could dither at 16px)
Algorithms: Dec guide mode = OFF
Last edit: 1 year 6 months ago by Euripides.
1 year 6 months ago #64676

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Thank you for sharing your experience on guiding the iOptron SGP. Mount super portable but guiding still a challenge. I have finally given up on internal guiding and switched to PHD2 which is working but not perfectly. I have not been able to connect the PHD2 program running on SM+ with the guiding tab on Ekos. Thanks for your suggestion on dithering. Will definitely give that a go. Hope that will smooth out the erratic corrections.
1 year 6 months ago #64706

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Have you changed the guide selection to PHD2 in your profile, before running it?


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1 year 6 months ago #64725

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