Cradled in cosmic dust and glowing hydrogen, stellar nurseries in Orion the Hunter lie at the edge of a giant molecular cloud some 1,500 light-years away. Spanning nearly 25 degrees, this breath-taking vista stretches across the well-known constellation from head to toe (left to right). The Great Orion Nebula, the closest large star forming region, is right of center. To its left are the Horsehead Nebula, M78, and Orion’s belt stars.
Image:
Annotated Image:
Equipment:
- Nikon D800
- 50mm f1.4 lens
- GEM 28
- NINA
- Nikonhacker
Acquisition:
- ISO 800, F2.8
- Taken from a bortle 1 zone in Northwest CT
- 155 x 240s subframes (10 hours) – Taken on 12/26/2022, 12/27/2022
Processing:
Pre-processing and stacking
- All subframes were calibrated and normalized through WBPP
- The subframes were debayered and split into monochrome channels
- The subframes were registered with distortion correction
- the subframes were registered based on a PSF snr estimate
- The subframes were normalized using local normalization
- Each channel was integrated separately using the ESD clipping algorithm
Preparation of all frames:
- Stacking artifacts were cropped
- the RGB channels were combined to create an RGB image
- the RGB image was plate solved
- DBE was applied iteratively
- the RGB image was photometrically color calibrated
Linear noise reduction
- A low-contrast mask was applied
- Two iterations of TGV noise reduction were applied, one targeting high-frequency noise and one targeting low-frequency noise
- A medium-contrast mask was applied
- MMT targeting all 8 scales was applied to remove large-scale noise
Stretching
- The stars were seperated from the nebula using Starnet 2
- the RGB image was stretched using Arcsinh stretch
Non-linear adjustments:
- LRGB combination
- HDR, LHE, and curves to increase local contrast
- MLT was applied targeting 5 layers of luminance
- The background level was set to .09
- the stars were stretched using Arcinh stretch
- The image was relinearized and the stars were added back