- Exposure time: 6 hours, 20
minutes (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: -18 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
- SQM: - (not measured)
- Location: Zoetermeer, The
Netherlands
- Date: September 28 - 29, 2011
Workflow
Image acquisition:
- Capturing 19 light frames of 1200s
Pre-processing
in
Nebulosity
(v2.3.5),
RegiStar
(1.0.7)
and Sigma
Beta
10:
- Pre-processing the light frames
with
a master bias frame (from
library) in Nebulosity
- Subtracting
the
bad
pixels
from
the
pre-processed
light
frames
with
a
bad
pixel
map
(from
library)
- Aligning
(registering) the pre-processed, bad
pixels subtracted light frames in
RegiStar
- Stacking
the individually saved registered files with "Standard Deviation
Masking" algorithm in Sigma
Beta 10
- 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
"GradientXTerminator" and "Distort > Lens Correction" filters due to
lack of flat frames
- Applying
Astronomy Tools v1.6 "Local Contrast Enhancement" action (applied
locally by using a clipping mask)
- Removing
some dust halos (donuts) with the Clone Stamp Tool due to lack of flat
frames and a filty sensor (naughty me...)
|
