Sh2-91
in H-Alpha + OIII + RGB
First up is the Narrowband data combined with the RGB via
the Foraxx script in PixInsight:
Next up is the same data combined using Photoshop and layering the Ha
and OIII on top of the RGB using clipping masks and Lighten Blend Mode
and dictating which colour each layer would affect:
And this subtle variant where I created an HOO image in Photoshop first then layered the RGB over top using Lighten blend mode:
And just to show how faint this is, here's the pure RGB stretched HARD!
From
Google's AI Summary: " Sh2-91, also called the Little Veil Nebula, is a
faint but expansive supernova remnant in the constellation Cygnus, near
the star Albireo. It is a small portion of the
supernova remnant
SNR G065.2+05.7, a vast, ancient, and distant structure that is larger,
further away, and older than the famous Veil Nebula. Due to its
faintness and the dense starfield it resides in,
Sh2-91 is a
challenging target for both amateur astronomers and imagers, often
requiring long exposure times and specialized filters to observe and
capture."
Image
Data:
Scope: AP155EDF
Camera: Moravian G4 (16803 ccd) w Astrodon Gen II filters
Mount: Paramount MX
Ha: 40 x 20 min; OIII 19 x 20 min; RGB 12/12/13 x 10min
Lucknow, Ontario, Canada
Aug 2025
Images acquired using TSX and CCD-Commander
Processed in PixInsight and Photoshop as follows:
PixInsight:
RGB:
Gradient Removal, SPCC, BlurX, NoiseX, Curves, HT,
StarReduction. Save
as TIFF
H-Alpha: Gradient Removal, BlurX, NoiseX, StarX, Curves, HT.
Save as TIFF
OIII: Same as H-Alpha
Foraxx script applied to the Ha and OIII using unstretched stars
Stars-back-in pixel math to add the RGB stars to the Foraxx image. Save
as TIFF
Photoshop:
Tweaked the Forax + RGB image then Save for Web
RGB split into channels; Starless Ha and OIII added via layers with
clipping masks. H-Alpha assigned to Red and OIII assigned to Blue and
Green. All at 80%
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