NGC2244, Rosette Nebula, Altair 183M, 20x180s

[turfpit]

The Rosette is not best placed for me now as it is moving into the sky-glow produced by the Manchester (UK) conurbation. My intent was to capture extensive nebulosity at the expense of star saturation (in the open cluster NGC2244). Full image here https://www.astrobin.com/393465/ .

_NGC2244-20x180s-g200-bl30.jpg (229.46 KiB) Viewed 1582 times

Equipment: Altair 66ED refractor, Altair 183M camera, 0.8x reducer/flattener, Celestron AVX mount.
Software: SharpCap 3.2, FITS Liberator, SiriL 0.9.10, Gimp 2.10.
Capture: 20x180s, 20 darks, 100 bias, 100 flats. *Unguided*.

The black level setting of 30 in SharpCap was decided by taking single bias frames and using the minimum black level setting which gave a centralised/balanced histogram in FITS Liberator.

Mount alignment was achieved with polar scope, 2 alignment stars, 4 calibration stars and an All Star Polar Align. Focus was with a Bahtinov Mask.

SiriL: calibrate, register, stack frames, background extraction, apply histogram transformation and export to TIFF.
GIMP: Curves, levels, shadows-highlights, contrast, slight noise reduction.

If I get a chance, I will repeat this capture with the same exposure (maybe gain 400) but using an Ha filter.

Dave

[ALTAIRH183M]
Output Format=FITS files (*.fits)
Capture Area=5440x3648
Binning=1x1
Pan=0
Tilt=0
Colour Space=MONO12
Fan=On
Temperature=13
Black Level=30
USB Speed=1
Auto Exp Target=144
Frame Rate Limit=Maximum
Analogue Gain=200
Exposure=180000
Timestamp Frames=Off
Banding Threshold=35
Banding Suppression=0
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=2019-02-26T19:54:53.9002407Z
SharpCapVersion=3.2.5926.0

[oopfan]

Pushing the 183M to the max!

[turfpit]

Pushing the imager to the max perhaps? The camera seems ok once a good combination of capture settings have been worked out. I must try for a longer integration time, maybe using the IDAS LPS P2 or Ha filter.