Quote:
Originally Posted by montewilson
Jase - Very kind and constructive as usual. What FWHM do you normally get with your images. It seems I am getting about 4", this image, for reasons not clear to me at the moment hovered around 7". I got a trial copy of CCDInspector to help me evaluate my focusing better.
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Based on my imaging run logs (below) ~6" appears the norm. I do get different values with the Ha filter. Also varies depending on the sky conditions.
14:22:02 Plate-solve pointing image.
14:22:03 3973 image stars found
14:22:04 1125 catalog stars found
14:22:04 Solved! 227 stars matched.
14:22:04 Average residual is 0.45 arcsec.
14:22:04 Pointing error is 2.348 arcmin @ angle 13.71
14:22:04 Image FWHM is 6.1 arcsec (1.74 pixels)
14:22:04 True focal length is 53.2 cm.
14:22:04 True image center (J2000): 10h 37m 46.8s -61 45' 59.61"
14:22:04 Imager sky position angle is 243.1 deg.
14:22:04 Image FWHM is 6.1 arcsec (1.74 pixels)
14:22:06 [sync] pointing model updated
....
14:39:37 Plate-solve final image
14:39:51 56891 image stars found
14:39:53 17099 catalog stars found
14:39:58 Solved! 305 stars matched.
14:39:58 Average residual is 1.13 arcsec.
14:39:58 Pointing error is 0.146 arcmin @ angle 33.13
14:39:58 Image FWHM is 9.0 arcsec (2.59 pixels)
14:39:58 True focal length is 53.2 cm.
14:39:58 True image center (J2000): 10h 37m 42.8s -61 48' 09.15"
14:39:58 Imager sky position angle is 243.1 deg.
14:39:58 Image FWHM is 9.0 arcsec (2.59 pixels)
14:39:58 (avg FWHM = 6.81 arcsec)
....
14:58:35 Plate-solve final image
14:58:50 56994 image stars found
14:58:51 17099 catalog stars found
14:58:55 Solved! 306 stars matched.
14:58:55 Average residual is 0.72 arcsec.
14:58:55 Pointing error is 0.110 arcmin @ angle 14.48
14:58:55 Image FWHM is 9.1 arcsec (2.62 pixels)
14:58:55 True focal length is 53.2 cm.
14:58:55 True image center (J2000): 10h 37m 42.3s -61 48' 10.13"
14:58:55 Imager sky position angle is 243.1 deg.
14:58:55 Image FWHM is 9.1 arcsec (2.62 pixels)
14:58:55 (avg FWHM = 7.58 arcsec)
....
15:02:02 Plate-solve pointing image.
15:02:03 2655 image stars found
15:02:03 567 catalog stars found
15:02:04 Solved! 176 stars matched.
15:02:04 Average residual is 0.34 arcsec.
15:02:04 Pointing error is 3.257 arcmin @ angle 349.98
15:02:04 Image FWHM is 5.4 arcsec (1.56 pixels)
15:02:04 True focal length is 53.2 cm.
15:02:04 True image center (J2000): 10h 49m 49.8s -64 45' 22.46"
15:02:04 Imager sky position angle is 243.2 deg.
15:02:04 Image FWHM is 5.4 arcsec (1.56 pixels)
15:02:06 [sync] pointing model updated
....
15:19:03 Plate-solve final image
15:19:17 65919 image stars found
15:19:18 8728 catalog stars found
15:19:20 Solved! 345 stars matched.
15:19:20 Average residual is 0.59 arcsec.
15:19:20 Pointing error is 0.120 arcmin @ angle 320.35
15:19:20 (pointing corrector updated with this observation)
15:19:20 Image FWHM is 8.4 arcsec (2.41 pixels)
15:19:20 True focal length is 53.2 cm.
15:19:20 True image center (J2000): 10h 49m 54.4s -64 48' 29.35"
15:19:20 Imager sky position angle is 243.2 deg.
15:19:20 Image FWHM is 8.4 arcsec (2.41 pixels)
15:19:20 (avg FWHM = 6.18 arcsec)
....
15:35:51 Plate-solve final image
15:36:05 66317 image stars found
15:36:06 8728 catalog stars found
15:36:08 Solved! 348 stars matched.
15:36:08 Average residual is 0.6 arcsec.
15:36:08 Pointing error is 0.130 arcmin @ angle 311.45
15:36:08 Image FWHM is 7.3 arcsec (2.08 pixels)
15:36:08 True focal length is 53.2 cm.
15:36:08 True image center (J2000): 10h 49m 54.2s -64 48' 29.73"
15:36:08 Imager sky position angle is 243.2 deg.
15:36:08 Image FWHM is 7.3 arcsec (2.08 pixels)
15:36:08 (avg FWHM = 6.64 arcsec)
....
15:52:42 Plate-solve final image
15:52:56 65301 image stars found
15:52:57 8728 catalog stars found
15:52:59 Solved! 349 stars matched.
15:52:59 Average residual is 0.58 arcsec.
15:52:59 Pointing error is 0.108 arcmin @ angle 326.74
15:52:59 Image FWHM is 8.6 arcsec (2.48 pixels)
15:52:59 True focal length is 53.2 cm.
15:52:59 True image center (J2000): 10h 49m 54.6s -64 48' 29.48"
15:52:59 Imager sky position angle is 243.2 deg.
15:52:59 Image FWHM is 8.6 arcsec (2.48 pixels)
15:52:59 (avg FWHM = 7.43 arcsec)
....
15:57:05 Updating pointing...
15:57:07 (taking 10 sec. exposure, Clear filter, binning = 1)
15:57:40 Plate-solve pointing image.
15:57:41 2879 image stars found
15:57:41 658 catalog stars found
15:57:42 Solved! 218 stars matched.
15:57:42 Average residual is 0.37 arcsec.
15:57:42 Pointing error is 5.777 arcmin @ angle 311.70
15:57:42 Image FWHM is 5.5 arcsec (1.58 pixels)
15:57:42 True focal length is 53.2 cm.
15:57:42 True image center (J2000): 11h 07m 43.0s -63 40' 52.25"
15:57:42 Imager sky position angle is 243.2 deg.
15:57:42 Image FWHM is 5.5 arcsec (1.58 pixels)
15:57:44 [sync] pointing model updated