IC1396 is a massive emission nebula in the constellation Cepheus. This nebula is so large I couldn't even fit the entire structure within my frame, yet you could easily fit 5 full moons across this image from our perspective. Within this nebula are tendrils of dark dust and most noticeably the "Elephant's Trunk" sprawling out near the bottom of the image. Ionized Sulfur, Hydrogen, and Oxygen molecules within the nebula were mapped respectively to Red, Green, and Blue to create this false-color image.

Equipment:

OTA: William Optics GT81 w/0.8x reducer (382mm fl at f/4.7)

74mm aperture stop-down ring (brings scope to f/5.2)

Mount: Orion Sirius EQ-G (HEQ-5)

Guidescope: Orion 50mm guidescope

Guiding camera: Orion StarShoot Autoguider

Imaging camera: ZWO ASI1600MM-Cool

Accessories:

DeepSkyDad Autofocuser AF1

QHYCCD PoleMaster

Software:

SGP

PHD2

CdC

PixInsight

Acquisition:

Location: Flower Mound, TX (Bortle 7)

Dates: 7/17/19, 7/18/19, 7/19/19, 7/20/19, 8/10/19, 8/11/19, 8/12/19

Gain: 200 Offset: 50

Camera temp: -10C

Ha: 396x180" Astrodon 5nm

SII: 49x600" Astrodon 3nm

OIII: 51x600" Astrodon 3nm

Total integration time: 36hr 28min

64x darks per calibration (master from library)

30x flats per calibration

200x bias per calibration (master from library)

Preprocessing:

Batch PreProcessing script to generate calibrated images

StarAlignment

LocalNormalization

ImageIntegration

DrizzleIntegration

DynamicCrop

DBE

Luminance Processing:

Duplicated the master Ha to use as the luminance

Deconvolution

ArcsinhStretch and HistogramTransformation to bring to non-linear

ExponentialTransformation to push nebulosity

LocalHistogramEqualization

MultiscaleLinearTransform for sharpening

HistogramTransformation

Preparing separate Sii, Ha, and Oiii linear masters for tonemapping (applied to each master individually):

TGV & MMT noise reduction (via Jon Rista's method)

ArcsinhStretch and HistogramTransformation to bring to non-linear

Removed stars via StarNet++

Further removed background artifacts with MMT

DBE on the SII and OIII channel to help corners

LinearFit to Ha

Combined prepared Sii, Ha, and Oiii masters with ChannelCombination:

R: Sii

G: Ha

B: Oiii

Tonemap Processing:

HistogramTransformation to balance channels

Several a/b channel CurvesTransformations using ColorMasks to alter the colors to an aesthetically pleasing palette

MMT to heavily noise reduce any artifacts

CurvesTransformations to fix the over saturation near the bright stars.

Combined Tonemap with Luminance using LRGBCombination:

CurvesTransformation for contrast

MorphologicalTransformation for slight star reduction

UnsharpMask with a StarMask to harden up the soft stars a tad

HistogramTransformation to pull the white point in a little

CurvesTransformation with a red ColorMask to help reduce reds in the corners

Resampled to 30% for web posting