Hy

I know and was happy to reach the 50" total error, but guiding, later on, was giving me 3-4 degrees of error. This didn't happen the time before (it was flawless)

I have a question that could e basic ut worth checking, as I use OAG, in both PHD & Internal guider, I enter my scope parameters as guide scope parameters ()and the camera is the guide camera), but I was thinking that I only look into a small portion of the scope FOV periphery and not the whole aperture. Does this affect the guider calculations?

I believe that only your focal length, and the guide-camera's pixel size matter.
I don't believe the aperture matters, though I also believe the aperture you used is the correct one.
Hy

Question. Is the all-sky polar alignment process sensitive to cone error?

my understanding of the principle of operation is, that the algorithm is not depending on a perfect alignment of the scope or camera in relation to the mount axis. The algorithm will always find the point in the sky around which the axis of the mount revolves, i.e. the MOUNT will be polar aligned. Whether your scope is parallel to the mount axis or not is a different question. So even with a pefectly polar aligned mount axis you could still have a cone error. But the PA algorithm should not be affected by this.
Probably Hy can comment on this as I just derive this from my theoretical understanding.

A  quick question, apologies if it has been covered earlier in this long thread:

My CEM70 is often persnickety about doing the rotations in the polar alignment assistant, so I usually check "Manual rotation". When I get the nice triangle in the PAA, the alt-az adjustments don't move the star along the legs of the triangle, but in some other directions. Is it expecting that the mount has returned to the zero position before clicking "Refresh"? That would be a bit odd, since it's plotting the triangle on the third image, which is at 60° RA from zero, and I'm prompted to select a star there. (I don't know if clicking on a new star even works once you've clicked "Refresh".)

My CEM70 has <em>also</em>  been rather persnickety about parking and returning to home position in the past, I know that Jasem looked into this for iOptron mounts at least once but I'm rather chary about letting it smack into the tripod again to discover if the problem still exists so I have the "park afterwards" checkbox off too.

@Dirk, @Andrew:  I would agree with Dirk that is should be unaffected by cone error. 

@Rick: The refresh should be done in the same mount position as the last capture. That is, the mount is only moved twice.
It captures the first image, it slews in RA, it captures the 2nd image, it slews a 2nd time in RA, it captures the third image.
At this point the refresh/correction procedure is done, with no further mount movements, except of course, for adjusting the alt and az knobs
to correct the mount's polar alignment.

I agree that I believe you can't change your star selection after you click refresh, probably best to select the star when it asks before it even changes to that screen.

Hy

Huh! Wonder why it's whacked for me, then. Something about the CEM70? Well, it's not really an issue. I use the PAA as a backup and quantitative assessment of my iPolar solution now anyway.

However, I was just reading up on the no-polaris alignment and was gobsmacked. That is quite the feature, my friend. Can't wait to try it out -- it literally opens new horizons for me, i.e. in my tree-cave back yard I may be able to move around until I have a patch of sky that includes a target, rather than just using the tiny slice from which I can see Polaris.

I tried aligning from way back under the trees, no northern visibility at all. Lined up the tripod by aligning the center post with a leg on a heading of 000° using my trusty 50-year-old Boy Scout compass (magnetic declination is negligible here). Slewed to visible sky at about 130° az and 35° altitude. Ran the PAA, the azimuth was so far off the triangle didn't even fit in the camera frame. Wound up running it for three or four cycles overall, PAA said 40", PHD Guiding Assistant said 2'. I'll take that!

Star still wasn't tracking the triangle, however. No matter, since the helpful circle guided me to the correct adjustments quite easily, so long as I didn't go too fast. Racking the azimuth more or less followed the hypotenuse, but not quite. Altitude was of course about perpendicular to that. Mount was pretty close to level by the bubble in the base. Does sensor orientation matter? My camera was at some completely random rotation since I was mostly just playing around.

Chris and Hy, this is the nuts. Terrific work, and it will make a big difference to my imaging. Even when I don't have good targets in my available slice of sky in the back yard, I can use that time to debug hardware and workflow instead of infringing on valuable remote-site dark-sky time. Bravo!

Duplicated

Let me first say thank you for such a great piece of software and specially for this new polar alignment method, a life saver for all of us that don’t have direct view to Polaris.

I’ve successfully used the method to get under 1’ error, having tried at different sky locations (I have a clear view NE-East-South).

After doing the polar alignment I use PHD2 for guiding so I usually run Guiding Assistant to confirm the PA error. The problem is that there is a huge misalignment between both, yesterday for example I finished Ekos PA under 1’ but when I run PHD2 guiding assistant it reported 42’, and I think PHD2 was right as the drift was evident. After that I run the drift alignment in PHD2 and I was able to get under 3’ of error which was good enough for imaging. Unfortunately I wasn’t able to measure back the PA error in Ekos as it refused to plate solve giving a timeout (never happened before)

What could be causing this deviation? My only guess is that there is some error in the configuration. Camera and focal length setting were set equally in both, however my guide scope has theoretical FL of 120mm, but when I did plate solving in Ekos for the first time it reported 128mm based on the FoV calculation, so I set it like that since the beginning. Seems strange to me that there is a 7% variation between the manufacturer theoretical FL and the real one, maybe this is the error?

Any suggestions? This is driving me nuts, it takes me forever to do PHD2 drift alignment, min 1h, so it would be amazing if I could use Ekos and have PA done in 10min.

Thanks!

Looks like other users are reporting the same here: indilib.org/forum/ekos/10056-inconsisten...ignment-results.html

I will close this topic and we'll continue there.