Quote:
Originally Posted by TrevorW
I spent last night until 2am capturing data on HH
6min 10 and 15min subs with the 80ED and QHY8 OSC
all washed out due to the moon
should I have used my HA filter when the moon is full  |
If you're really close to the moon you'll always get skyglow so it doesn't matter what filter you are using. It will always be a challenge to extract details very close or above the sky count. That's where calibration and good flat fielding will make a world of difference.
You'll find that debayering to red only will minimize skyglow. Also flat fielding will reveal noise on the edges of the field (vignetting) that will show as white when you calibrate so you might mistake that for inverted vignetting. The solution is to push your subs longer and also push your flat duration 25% longer so they're brighter. That will get rid of the 'glow' you get in the corners and outside the field. You'll have to test different values depending on your scope but in my experience double the ADU value of the center part of your flat for Ha based on the value you normally aim for with no filter on and that works for you.