- Exposure time: 4 hours (20 min.
sub-exposures)
- Lens/telescope: INTES 150 mm (6")
MK-69 at f/6
- Image scale: 1.24 arcseconds per
pixel, FOV 68.5' x 51.6' (F = 900 mm at 5.4 micron pixels)
- Camera: SBIG ST-8300M (T: -30 degrees
Celsius) with Baader
H-alpha 7 nm narrowband filter
- Mount: Astro-Physics Mach1 GTO
(guide rate: 1x, PEM activated)
- Guiding: TS OAG + SX
Lodestar +
PHD (small dither, settle < 0.5)
- SQM: - (not measured)
- Location: Zoetermeer, The
Netherlands
- Date: February 2 - 3, 2012
Workflow
Image acquisition:
- Capturing 12 light frames of 1200s
- Capturing 1 flat frame of 60s
with a Geoptik Flatfield Generator
Pre-processing in
Nebulosity
(v2.3.5)
and Sigma
Beta
10:
- Pre-processing the flat frame
with
a master bias frame (from
library) in Nebulosity
- Pre-processing the light frames
with
a master bias frame and the
pre-processed flat frame
- Subtracting
the
bad
pixels
from
the
pre-processed
light
frames
with
a
bad
pixel
map
(from
library)
- Matching
the histrograms of the pre-processed, bad pixel substracted light frames
- Aligning (registering) the
pre-processed, bad pixels subtracted light frames and saving
each individual file
- Stacking
the individually saved registered files with "Average of Medians"
algorithm in Sigma
Beta 10
- Trimming the dark edges by making
a crop
- Applying the "Digital Development
Processing (DDP)" tool
Post-processing
in
Photoshop
(CS4):
- Adjusting levels and curves in
order to get a smooth and proper histogram and as much dynamic range
as possible without clipping
- Applying
Astronomy Tools v1.6 "Local Contrast Enhancement" action (applied
locally on the high contrast details by using a clipping mask)
|
