Except for the first two, the rest were quite consistent within tolerance. The AZ/AL error would of course be different depending on where are you looking in the sky. These are all done with primary scope (Orion EON 120mm) on QHY268M Pro.
Well, I think it would be more accurate to say that from the data Jasem took, the procedure's variability isn't too bad (but 2 arcmins variability seems a bit higher than what is desired considering we're platesolving a solution IMO). Jasem didn't provide an output value comparison to PHD2's drift alignment output value. This or another vetted drift align output value is needed for comparison before you can say the software "works". Consistency doesn't necessarily imply precision, and result precision is the goal so you know when good enough PA occurs.
Edit: something just caught my eye in Jasem's data. All the tests were done starting on Polaris park position? That's good for the OP test, but what about away from Polaris (say 60 degrees or lower DEC?). This is where I experienced problems. Jasem, could you possibly do another set away from Polaris and if possible include a drift align output value from PHD2 for comparison? That would be very helpful....
Like magic! I set the FL to 120mm ignoring the warning message in Ekos and was able to get similar PA error both in Ekos PA and PHD2 drift alignment.
The routine I followed was to first run PHD2 drift alignment and guide assistant first, which reported an error of 6’5”.
Then I run Ekos PA and before adjusting the knobs it reported an error of 4’5”, a bit of a gap but much better than my previous tries.
Then I adjusted to 0’5” in Ekos and run a second iteration which confirmed the same error practically. I then run PHD2 guiding assistant and got 1’5” error.
So in my case there is something like 1-2 arcminutes of deviation between both, for me enough to use the much faster Ekos PA routine. I was able to confirm it by taking some 5mins pictures with perfect round stars.
So in my case it seems the wrong FL was the error, I hope this helps others.
Still struggling with this one.
I am using the skyguider pro. Should I turn tracking _off_ while I am doing the procedure ?
I want to try the PHD2 Drift alignment as suggested by others, but my visibility on the sky is limited by buildings. E.g. I cannot see the intersection of the meridian and the celestial equator on the south side. Does this matter ? Can I still try it out regardless ?
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
Waveshare Stepper Motor Board - DIY Focuser
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
Just wanted to share I found the cause. The skyguider pro was not entirely stable when doing PAA. I fixed this and now the results are much better. however, still some minor variation between consecutive runs.
That was my issue in the end as well, the position of the guide tube was not ideal, I changed it from the finder shoe to under the dovetail and this gave me the best results confirmed by PHD2 guiding assistant.
Still minor variation between consecutive runs as well, in the few arc minutes though (<5) and mostly on the RA axe, I think that is due to other factors that probably change from one run to another like wind, flexures, gear meshing, etc.
In any case this is now totally usable and will finally take me away from the looong PHD2 drift alignment method I was using until now.