Plate solving problem

Anything that doesn't fit into any of the other forums
Post Reply
Bob_in_PC
Posts: 4
Joined: Wed Jun 30, 2021 1:10 pm

Plate solving problem

#1

Post by Bob_in_PC »

Hi - I'm having issues with platesolving. I seem to have Stellarium, Sharpcap 4.0, and PHD2 all installed and running properly. I have Stellarium doing the mount control and it slews when commanded through Stellarium fairly close to desired target. The polar alignment tool works perfectly and I get excellent PA. But, when I hit the plate solve and re-sync button, it takes ~15 minutes for it to go through the plate solve routine after which it shows it didn't solve (outside of the 15 degree window). I actually did get it to plate solve a couple of times but it wouldn't re-sync. But, mostly it doesn't plate solve. Also, I am using an Orion mini 50 mm and an Orion Starshoot Autoguider camera. I'm trying to autoguide my DLSR with 135 mm lens - the guide scope is 162 mm FL. I am attaching the log file.
Log_2021-09-27T20_30_28-1740.log
(985.47 KiB) Downloaded 45 times
Thanks in advance. Bob
User avatar
admin
Site Admin
Posts: 13177
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: Plate solving problem

#2

Post by admin »

Hi Bob,

I think the first thing is that the number of stars being found is probably a bit on the high side - typically 250-350 in your log. Try increasing the sigma value in the SharpCap plate solving settings to bring the number down (probably to 50 to 100). If the star detection is over sensitive and is finding hot/warm pixels as stars then that can cause problems.

Next thing to do is to upload one of your images to nova.astrometry.net to check that it (a) solves there and (b) to look at the field of view and co-ordinates that come out. It's worth checking that you have the correct index files installed for your field of view once you know it - again without the correct index files, you will not get a solution

Another point is to check that the RA/Dec co-ordinates on your mount are actually close to the real pointing of the telescope - SharpCap sets a limit of 15 degrees for the search area around the current co-ordinates, so if you are further out than that, you will get no result.

If none of this helps, please feel free to share an image that you are trying to solve (ideally in PNG or FITS format) for us to investigate.

thanks,

Robin
Post Reply