Veil Nebula in Natural Color: A DSLR Astrophotography Journey

Astrophotography is a journey of patience, skill, and a touch of DIY ingenuity. Today, I'm thrilled to share a project that truly embodies these principles: capturing the Veil Nebula in its natural glory using a standard DSLR and a custom-built star tracker. This was my first multi-night project on a single object and my first time utilizing a star tracker, and the results have honestly blown me away compared to my previous untracked attempts.

The Equipment Setup:

The goal was to push the capabilities of a readily available DSLR and to experiment with a passion project: a self-built star tracker. Here's what made this image possible:

• Camera: Nikon D800 (Unmodified)
• Lens: Nikon 200-500mm f/5.6 @ 500mm f/5.6
• Tracking Mount: OG Star Tracker V2 (self-built and modified, featuring a custom DEC bracket and counterweight system)
• Specialty Accessory: Custom diffraction grating lens cap for 4-point star spikes

The Acquisition: A Marathon of Light

Capturing nebulae requires significant exposure time to bring out faint details. This project involved stacking a substantial amount of data, spread across multiple nights under Bortle 5 skies:

• Exposure Details: A total of 3489 frames, each 20 seconds long, accumulating to 19.38 hours of total exposure time across 7 nights.
  • Night 1: 653 x 20s
  • Night 2: 308 x 20s
  • Night 3: 418 x 20s
  • Night 4: 438 x 20s
  • Night 5: 510 x 20s
  • Night 6: 556 x 20s
  • Night 7: 602 x 20s
• Important Note: No calibration frames (flats, darks, or bias) were used in this acquisition.

The Processing Pipeline: From Raw to Refined

Processing deep-sky images is often as crucial as the acquisition itself. This project involved a meticulous, multi-stage approach:

Per Night Processing:

1. Raw Conversion: Light-weight adjustments in Lightroom, including applying lens profile corrections.
2. Stacking (Initial): Registration and stacking of each night's data independently using Siril.

Combined Stack Processing:

1. Stacking (All Nights): All 7 individual stacks were registered and stacked together in Siril.
2. Noise Reduction: Green noise removal was performed in Siril.
3. Background Extraction: Utilized GraXpert for effective background extraction.
4. Denoising: Applied denoise processing with GraXpert.
5. Star Removal: Used StarNet to create a starless version of the image.
6. Stretching: Individually stretched the starless image and a generated star mask in Siril.
7. Compositing & Enhancements: Combined the starless nebula and the star mask in Photoshop. Screen blending, brightness, and contrast masks were used to isolate and enhance the nebula's details, followed by a minor color boost to reveal fainter structures.

The Results and Future Aspirations

The improvement from this tracked, multi-night project compared to my previous untracked attempts is truly remarkable. The level of detail captured in the delicate filaments of the Veil Nebula is something I find incredibly beautiful and rewarding. While I'm extremely happy with this result, I know there's even more potential to be unlocked with further time and refined processing techniques.

I'm eager to continue learning and experimenting, and I welcome any and all advice and tips from the community! Clear skies!