IC 1396 Captured in the Iconic Hubble Palette

Behold the majestic IC 1396, also known as the Elephant Trunk Nebula, presented here in the awe-inspiring Hubble color palette. This vast emission nebula, located in the constellation Cepheus, is a region of active star formation, illuminated by the radiation from its central star, HD 206267.

This image is the result of dedicated effort under Bortle 6/7 skies throughout July 2025. A total of 27 hours of H-alpha and SII data, combined with 22.5 hours of SII and OIII data, were meticulously acquired and processed to bring out the intricate structures and vibrant colors of this celestial masterpiece. Each sub-exposure lasted 1,000 seconds, a deliberate choice aimed at achieving a specific ADU reading above the background noise, while balancing the risk of tracking or atmospheric disturbances.

The Gear Behind the View

Achieving such a detailed image requires a robust setup. The equipment used for this capture includes:

• Scope: Askar SQA70
• Camera: ZWO ASI2600MC Pro
• Mount: ZWO AM3
• Guiding: ZWO ASI220MM Mini + WO 32mmUniGuide Scope
• Filters: Optolong L-Ultimate + Altair SII OIII DualBand Ultra 4nm

The Art of Processing

The journey from raw data to this final image involved a sophisticated processing workflow:

1. Initial Calibration: Weighted Batch Preprocessing (WBPP) was performed on all subs, yielding two master light frames – one for each filter set.
2. Image Preparation: Dynamic Crop was applied, followed by Image Solver and Spectrophotometric Flux Calibration (with manual input for Altair filter settings) and Spectrophotometric Color Calibration.
3. Channel Separation: Channel Extraction was performed on each master light frame.
4. Integration: Image Integration was used to combine the four OIII channels, resulting in three distinct channels: SII, H-alpha, and OIII.
5. Refinement and Combination: The image underwent refinement with graXpert and blurXterminator. LRGBCombine was employed to merge the three narrowband channels into a single image.
6. Stretching and Star Reduction: The image was stretched using HT_Stretch_Unlinked. Magenta stars were corrected, followed by starXterminator and Morphological Transformation to reduce star size.
7. Noise Reduction and Normalization: NoiseXterminator was applied to the starless image, followed by NarrowbandNormalization.
8. Color Enhancement: Curve Transformations were used to enhance colors: a Green Mask was used to decrease green, a Cyan Mask to increase red, saturation, and blue while decreasing green, and a Yellow Mask to boost red. Overall saturation was increased, and an S-curve was applied to the RGB channels for contrast.
9. Detail Enhancement: DarkStructureEnhance was applied to the starless image with an amount of 0.2.
10. Star Reintegration and Final Touches: PixelMath was used to reintroduce the stars. A MultiscaleMedianTransformation was applied to the combined image for final refinement.
11. Final Polish: The image was exported to Lightroom for final adjustments and color grading.

This image is a testament to the power of modern astrophotography equipment and techniques, allowing us to explore the universe in breathtaking detail and color.