SGP FITS Conversion Causing error


I’ve noticed SGP converts my FITS files when uploading to If true, then this is almost certainly what is causing my failed plate solving attempts in SGP.

  • I’ve uploaded the same fits file to both SGP and and only achieve success when uploading manually to Furthermore, I’ve noticed the fits image I submit through SGP looks degraded, possibly binned?, when viewed on
  • I live in the middle of a city and require the use of narrowband filters. I’m sure the use of filters contributes to my SGP plate solving failures; however, with my original fits files handles it well.

Is it possible to add an option in SGP to upload the original fits file? OR, does anyone in the community have any ideas I can use to overcome the issue with the current version of SGP? Taking 3 minute exposures works, but I don’t view that as a solution (is that reasonable?).



Yes, SGP does downsample your image before sending it to Astrometry if the image is larger than 1200 pixels across. We can add an option to disable this. But it could result in an extremely large file getting uploaded to Nova.

I would recommend plate solving with a Lum filter though. You can still switch back to the narrowband filters for imaging. SGP has the option to do this currently. This is how I plate solve and I only shoot narrowband from home as I also live in an area with decent light pollution.