NGC7000 with Ha filter
Posted: Mon Sep 24, 2018 9:42 pm
Altair 66-ED refractor, Planostar 0.8x reducer/flattener, Altair 183M camera, Ha 7nm narrowband filter.
SharpCap 3.2 + FITS Liberator + Siril + GIMP 2.10
60 lights, 50 darks, 100 bias, 100 flats
exposure=90s, gain=1000, black level=150 [unguided]
I had to set the gain much higher than I am used to (100) in order to get a decent histogram. The other surprise was with taking flats, normally to get a reasonable histogram I use an exposure of 250ms but with the filter in use I had to use 15s. I also had to push the mount tracking capability by upping the exposure to 90s but it looks like the AVX held up here.
This was my first experience with a narrowband filter - some interesting challenges with settings . Quite pleased with the image but have noticed some horizontal banding that I will need to go away and investigate further.
Dave
Lights
[ALTAIRH183M]
Output Format=FITS files (*.fits)
Capture Area=5440x3648
Binning=1x1
Pan=0
Tilt=0
Colour Space=MONO12
Fan=Slow
Temperature=8.8
Black Level=150
USB Speed=2
Auto Exp Target=120
Frame Rate Limit=Maximum
Analogue Gain=1000
Exposure=90000
Timestamp Frames=Off
Apply Flat=None
Subtract Dark=None
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.5
#White Point
Display White Point=1
TimeStamp=2018-09-23T19:58:58.1949246Z
SharpCapVersion=3.2.5762.0
Flats
[ALTAIRH183M]
Output Format=FITS files (*.fits)
Capture Area=5440x3648
Binning=1x1
Pan=0
Tilt=0
Colour Space=MONO12
Fan=Slow
Temperature=8
Black Level=149
USB Speed=2
Auto Exp Target=120
Frame Rate Limit=Maximum
Analogue Gain=400
Exposure=15000
Timestamp Frames=Off
Apply Flat=None
Subtract Dark=None
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.5
#White Point
Display White Point=1
TimeStamp=2018-09-23T23:02:59.5309235Z
SharpCapVersion=3.2.5762.0