Do you have a sample file?

Yeah, sure! Here is the sub i used

www.dropbox.com/s/te6u033m5ncoze2/M45_Li...-57-40_015.fits?dl=0


The only thing I can see is that the solver says "Scale range: 13.7533 to 20.63 arcsec/pixel" but my image 5.92 arc/px

Is that your issue, you have it set at “F1150” that is not correct at all, no scope has that f ratio..... :0

So I just ran your image in my StellarSolver tester program. With the initial information in the header file it didn't solve with my normal options profile. So I tried unchecking the "use scale" and "use position" checkboxes to see what the issue was. I thought that it was probably a scale issue, since that has been a typical issue users have had. But no the scale was fine. In fact when it did solve it said the scale was: Pixel Scale: 5.92796" which is just fine with the pixel scale that was saved in the image. Then I checked the RA and DEC that was saved in the file, and I said "Whoa!" The RA and DEC saved in your file was RA: 0.0202806 and DEC: 89.8869. That is basically at the pole!! When I unchecked "use position" it solved right away and said this was the position: Field center: (RA,Dec) = (56.4615, 24.3425) deg.

Ok, I didn't see that coming!
So, how is this possible and where I have to look and resolve the issue? (As you can understand I have no clue...)

I agree, I expected it to be a scale issue, not because of the scale you reported, since that number was inflated due to downsampling probably, but because that is typically the reason folks have failed solves. No I didn't expect the position to be off. Was this the first solve of the evening? Had you just turned on your telescope? Did you do a cold start or a reset when it was already on an object?

I've made those changes too, but unfortunately no, the issue still remains I can't get it solved even on a simulator profile. I have just the same errors.

And to be honest I can't understand how those infos are written into the header - so I could change them. Maybe it is something fundamental on my profile that I do not know, cause till the previous version, everything was working properly.

And my setup is pretty simple : SkyGuider Pro, DSLR, ZWO.
My profile:
Mount = iOptron SkyGuiderPro (tried with Telescope Simulator too)
CCD: Canon DSLR
Guider: ZWO CCD


PS. Yes, it was my first and only session that night.

So really you don’t need to change the information about the telescope position in the header of the image that was taken, that is automatically taken from KStars and the drivers knowledge of the telescope location. When you first start up, your mount should probably be in the position looking at Polaris and then once started up, you should slew to your first alignment star and take a plate solve. Then do a couple more in different spots before you go to your target.

The.one exception to this is that some mounts/drivers have a warm start mode where if you have the scope still in the same spot as a previous run, you can just start right back up

The other part about what you said about getting a simulator plate solve to work, are you using the internal solver or ASTAP? And whichever one it is, do you have the right index files or catalogs?

My steps are quite usual, just PA and then "slew" (manually of course) to my target.

I've tried all the available solver combinations but none of them work. I have all the required index files (and even more).

Right now I can see that even the individual ASTAP installation can't solve the image (on my RPI4 and my Mac)

Try unchecking use scale and or use position and make sure that the alignment logging is turned on in ekos. Also when you say the index files are installed, please go into the ekos index file downloader and make sure it can find them .

When you say you “manually “ slew I hope you mean using the hand paddle and not just pushing the scope (unless there are absolute encoders)