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The Hole in the Trees Skybox | all galleries >> Deep Sky >> Planetary Nebulae > WeDe 1
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WeDe 1

Weinberger-Dengel-Hartl-Sabbadin 1 in Orion

Nebula is Ha mapped to red-magenta, stars are RGB. About two hours of OIII was captured, but showed no (or almost no) signal, so I didnít use it.

Exposure: Total exposure time about 21 hours, 59 x 20mins Ha, 20 x 2 mins per channel RGB. All bin 1x1. Captured over about 10 nights from January to March 2018.
Light pollution: Bortle 8 (white zone, NELM about 4.5)
Image scale at capture: 0.6 arcsecs/pixel = f/5.7
Scale of presentation: 1.2 arcsecs/pixel (50% reduction)

Scope: C11 (standard, not Edge) with Celestron 0.63 reducer
Mount: Paramount MX+, connected via ASCOM Telescope Driver 6.1 for TheSkyX, with MKS 5000 driver
Camera: SXVR-H694, connected via SX ASCOM driver (SX 1.2.2 also installed)
Filter wheel: Atik EFW2 with 7x1.25 carousel and Artemis driver
Filters: Astrodon 5nm Ha/SII, 3nm OIII, Type IIi LRGB
Rotator: Optec Pyxis 2", connected via Andy Galasso's 0.4 driver (Optec Pyxis Rotator AG)
Focuser: Rigel Systems GCUSB_nStep with driver version 6.0.7
OAG: Orion Thin OAG
Guide cam: Lodestar (first generation). 4 second exposures
Automation SW: Sequence Generator Pro beta
Guide SW: PHD2.6.3, connected to guide cam via native SXV driver
Platesolving: PlateSolve 2, failover to local 0.19 server
Collimation: Metaguide 3, using ASI120MM connected via ZWO Direct Show driver

Processing Workflow by Workspace in PixInsight 1.85

1. Calibration
BatchPreProcessing with flats, darks and bias, using Cosmetic Correction with master dark
Local Normalization

2. Stack and Mure Denoise
Blink to preview and reject a few frames
Subframe Selector to confirm selections and weight by FWHM and SNR
Image Integration
Mure Denoise

3. Luminance Linear Processing
Dynamic Crop
Dynamic Background Extraction

4. Luminance Stretching
Histo Trans
Masked Stretch
Curves Trans
Noise Reduction with TGV Denoise and Multiscale Median (following
David Aultís Astro Imaging Channel tutorial).
Local Histogram Equalization to enhance contrast inside nebula

5. RGB Linear Processing
LRGB Combination to merge RGB channels
Dynamic Crop (using the same icon as with luminance)
Dynamic Background Extraction
Photometric Color Calibration

6. RGB Stretching
Split luminance from RGB
Masked stretch on chrominance
Curves to boost saturation on chrominance
Histo Trans and Curves on luminance
LRGB Combination to merge luminance and chrominance
TGV Denoise

7. Color
Colorized Ha to red-magenta in PixelMath: mapped Ha to R, 0.14 to green, and 8% Ha+0.12 to blue.

8. Combine
Star removal, following David Aultís technique
With PixelMath max command, add starless nebula and RGB star field

9. Final
In Photoshop, clean up blue comatic halos on color layer with Radial Blur and desaturation sponge. Save as TIFF
Downsize 50% and save as JPG

other sizes: small medium large original auto
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Sakib 29-May-2018 16:59
It's always fun finding this in widefield Orion images!