Reverse Vignetting - 2022-07-24
East Veil Nebula - 2022-07-19
masterLight frame integrated in PixInsight, Red channel only. with STF stretch applied.
The image looks to be over calibrated by the Flats in that the dark vignetting in the corners of the Light subs now appear bright in the integrated master. Suspected problem is that Darks (45s) and Dark Flats (2s) do not have the same offset.
Both Darks and Dark Flats were captured with ZWO ASI6200MM using the ZWO ASCOM driver, which I believe should have applied Offset of 50 (DN 500) to both sets of subs. Both sets of subs look normal with a boosted STF stretch.
So far I have found that the Median and Min data numbers for the Dark subs are 11.0 and 0.0, respectively. TheMedian and Min data numbers for Dark Flat subs are 501.0 and 324.0, which seems in line with what I expected.
I believe that the Darks are not correct, and will produce another set.
Reverse Vignetting - 2022-07-24
East Veil Nebula - 2022-07-19
masterLight frame integrated in PixInsight, Red channel only. with STF stretch applied.
The image looks to be over calibrated by the Flats in that the dark vignetting in the corners of the Light subs now appear bright in the integrated master. Suspected problem is that Darks (45s) and Dark Flats (2s) do not have the same offset.
Both Darks and Dark Flats were captured with ZWO ASI6200MM using the ZWO ASCOM driver, which I believe should have applied Offset of 50 (DN 500) to both sets of subs. Both sets of subs look normal with a boosted STF stretch.
So far I have found that the Median and Min data numbers for the Dark subs are 11.0 and 0.0, respectively. TheMedian and Min data numbers for Dark Flat subs are 501.0 and 324.0, which seems in line with what I expected.
I believe that the Darks are not correct, and will produce another set.