A lot of short exposures trying to get the star colors alright.
Discussion of Exposure Length of RGB filtersOne thing I have noticed on stars is that the transmission levels (of photons) may vary very slightly even with "balanced' filters. There is a nice discussion on Cloudy nights:
https://www.cloudynights.com/topic/817210-lrgb-exposure-ratios-snr-balance-and-color-balance-for-qhy-600m/"The relative signal in each passband for L, R, G, B is
RelativeSignalQHY = {3.13,
1.00, 1.14, 1.05} QHY QE curve"
This may not look like much, but this is
14% more G than R. I was wondering why green was showing up in both R and B stars... maybe this is why.... of course I have different equipment, but I think the principles hold.
This resulted in my changing the exposures of my
RGB to 22 19 and 21 seconds respectively. These numbers were calculated to be optimal at 22 (sounds very low but higher blows out the centers of the stars in the ZWO) . Anyway, in PixInsight there is now less G in these stars.... seen by holding the cursor over the star and left button clicking.
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