Problems With Accurate SSlewing After PA

[hatflyer]

After I polar align with EQ mount (AZ-GTi), the slew to my first target is way off (e.g 40+ degrees), even tho mount/camera were aligned to north star after polar alignment. Alignment is set to where Alt is my latitude and Az is 0 (and DEC = 90, RA=0). It was close to that even before polar alignment started. Any idea why? I expect it to be off, which is why u need camera alignment, but by so much?

I use EQMOD to connect and NINA.

And if successfully slew and center with plate solve, the indicated Az/Alt is still way off (it is not re-set to adjust to the corrected position); will NINA know to set tracking rate to the centered object, or will it track using the faulty current Az/Alt coordinates?

Thanks.

[Gordon]

Make sure you are using conventional mapping units degrees, minutes and seconds. Rather than Decimal GPS coordinates.

This website can help.

https://gps-coordinates.org/coordinate-converter.php

[JayTee]

I want to make sure that you are using the correct nomenclature.

A polar alignment PA is when you physically move the mount so that the R.A. axis points to the NCP.

A goto alignment is where you use alignment stars and your time, date, and location so the HC can build an accurate Sky Map so that it knows where to point the telescope based on the object you've requested to view.

To get your best and most accurate setup, most of us do the following routine:
A rough PA ( physically setup your mount as best you can so it points to the NCP), followed by a two-star goto alignment, then back to refining your PA, and then a final two or three-star goto alignment to correct the movement created by the final PA.

I know it sounds confusing and a lot of work, but after you've done it a few times it shouldn't take more than 15 or 20 minutes. Some of this can actually be done before it gets fully dark.

[hatflyer]

I want to make sure that you are using the correct nomenclature.

A polar alignment PA is when you physically move the mount so that the R.A. axis points to the NCP.

A goto alignment is where you use alignment stars and your time, date, and location so the HC can build an accurate Sky Map so that it knows where to point the telescope based on the object you've requested to view.

To get your best and most accurate setup, most of us do the following routine:
A rough PA ( physically setup your mount as best you can so it points to the NCP), followed by a two-star goto alignment, then back to refining your PA, and then a final two or three-star goto alignment to correct the movement created by the final PA.

I know it sounds confusing and a lot of work, but after you've done it a few times it shouldn't take more than 15 or 20 minutes. Some of this can actually be done before it gets fully dark.

Yes, got all that. You are talking of using Synscan? Had issues there as well. I like the 3-point plate solve in NINA.

Does it matter if 1 star is on the opposite side of the meridian? I think with 2-star Synscan yes, they have to be on the same side, but NINA no. Anyway, my polar alignment is very accurate. It's the star alignment that isn't.

To use Synscan, u need to see the live view on the camera so u can center objects? Can't do that when camera is connected to the laptop. If I disconnect it, then re-connect I have to shut down NINA and re-boot, or it doesn't connect to my camera. Not sure what is lost when I shut down NINA and re-start.

Actually, if I part the mount, I can try PA with NINA then star align with Synscan with disconnecting the camera. Then park and re-start NINA with camera back connected.

[JayTee]

Now that we're talking about a plate solve with N.I.N.A., that's a whole different ball game. It's also a very accurate ball game. A 1 star go to alignment should be sufficient to get you close enough to your object wherever it is in the sky to let N.I.N.A. plate solve for it. This should, in theory, give you your best go to alignment.

[KathyNS]

After I polar align with EQ mount (AZ-GTi), the slew to my first target is way off (e.g 40+ degrees), even tho mount/camera were aligned to north star after polar alignment. Alignment is set to where Alt is my latitude and Az is 0 (and DEC = 90, RA=0). It was close to that even before polar alignment started. Any idea why? I expect it to be off, which is why u need camera alignment, but by so much?

I use EQMOD to connect and NINA.

And if successfully slew and center with plate solve, the indicated Az/Alt is still way off (it is not re-set to adjust to the corrected position); will NINA know to set tracking rate to the centered object, or will it track using the faulty current Az/Alt coordinates?

Thanks.

You didn't mention doing a goto alignment. Without it, you can expect slews to be off.

[hatflyer]

After I polar align with EQ mount (AZ-GTi), the slew to my first target is way off (e.g 40+ degrees), even tho mount/camera were aligned to north star after polar alignment. Alignment is set to where Alt is my latitude and Az is 0 (and DEC = 90, RA=0). It was close to that even before polar alignment started. Any idea why? I expect it to be off, which is why u need camera alignment, but by so much?

I use EQMOD to connect and NINA.

And if successfully slew and center with plate solve, the indicated Az/Alt is still way off (it is not re-set to adjust to the corrected position); will NINA know to set tracking rate to the centered object, or will it track using the faulty current Az/Alt coordinates?

Thanks.

You didn't mention doing a goto alignment. Without it, you can expect slews to be off.

That's what the step of slew and center is to do in NINA. The equivalent of a go to alignment. That is off, so I help it get to the target properly with the directional keys, and plate solve, but after that the next target is way off again. And Az/Alt still off.

[UkDave]

I use APT I always platsolve and sync mount from within one hour of the celestial equator never platesolve near the North Star region , ivo from Apt told me this and makes my Goto++ more accurate and centres in less steps since taking this advice I’ve never had any issues .

[Juno16]

Probably a dumb question, but you do have the “SYNC” button on in NINA plate-solving?

I don’t use Synscan myself. I use Cartes du Ceil to goto targets when I wast to slew “manually”. Gets me close.
Then, I use NINA plate-solving to center and sync to the target. I usually only use Cartes du Ceil when I want to manually slew and sync, manually focus, calibrate PHD2, or kill time waiting for my target to rise.

Mostly, I just power everything up, connect all equipment to NINA (I know that you use EQMOD, I use GreenSwampServer) start a sequence in NINA and the mount slews to the target, plate solves, centers, and syncs. It then runs an autofocus. That’s it.
Good luck!