Siril StarNet Pixel Math Photoshop processing M27 Dumbbell nebula

This shows processing steps to process M27 using Siril and Photoshop. Total Integration: 8,100 seconds (2.25 Hours) | 5-Minute Sub-exposures 📸 Capture Details Optics: Celestron SCT 9.25" Mount: iOptron CEM40 Imaging Camera: ZWO ASI2600MC (One-Shot Color) Guiding & Control: ZWO ASI290MM | PHD2 | NINA Stacking: Siril (OSC Processing Script) --- 💻 The Processing Workflow A deep dive into taking raw stacked data and turning it into a vibrant, sharp final image using a powerhouse software suite: Siril ➔ GraXpert ➔ StarNet++ ➔ Cosmic Clarity ➔ VeraLux ➔ Photoshop. #### 1. Pre-Processing & Linear Phase (Siril & GraXpert) Crop: Trimmed the edges to eliminate stacking artifacts. Background Extraction: Ran GraXpert BGE to remove gradients and ensure a flat field. Color Calibration: Plate-solved the image inside Siril and ran SPCC (Spectrophotometric Color Calibration) for accurate star and nebula colors. Star Correction: Experimented with Star Aberration Remover (noted some minor artifacts to watch out for). Star Separation: Ran StarNet++ to split the data into a Starless image and a StarMask for independent processing. #### 2. Enhancing the Nebula (Starless Processing) Sharpening: Applied Cosmic Clarity (Non-stellar amount: 0.5–1.0) to pull out the intricate gas structures of M27. Noise Reduction: Cleaned up the background using GraXpert Denoise (~0.5–0.7). The Stretch: Used VeraLux Hypermetric (Standard Stretch Target) to safely bring the nebula out of the linear phase, followed by minor Curves Transformations to taste. Local Contrast: Finished the nebula enhancement with VeraLux Revela to make the details pop. #### 3. Star Processing & Recomposition Star Stretching: Stretched the StarMask using Asinh (50–100) and Histograms to keep the star profiles tight and colorful without bloating. PixelMath Recomposition: Combined the stars and nebula back together using a screen blend formula: ~((~StarMask)*(~Starless)) How it works: This inverts both images, multiplies them, and inverts the result. It leverages the mathematical properties of a screen function to perfectly preserve and enhance the bright areas of both layers without clipping. #### 4. Final Polish (Photoshop) Brought the recomposed TIFF into Photoshop for the final touch-ups. Adjusted Levels to balance the background sky easter eggs and contrast. Used Adobe Camera Raw (ACR) for fine-tuning Saturation, Vibrance, and Clarity. --- If you enjoyed this processing walkthrough, don't forget to Like, Subscribe, and clear skies! 🔭