Sh 2-54: A Stunning Dual-Filter Narrowband and RGB Star Capture

This is a truly remarkable capture of the emission nebula Sh 2-54, brought to life through a sophisticated integration of narrowband and RGB data. The result is a stunning visualization of cosmic gases and the embedded stars that illuminate them.

The Journey to This Image

The creation of this image involved a significant investment of time and expertise, spanning approximately 20 hours of integration time. This was broken down as follows:

• 60x60 seconds for RGB Stars
• 180x180 seconds with the Optolong L-Extreme filter
• 200x180 seconds with the Askar D2 filter

This layered approach allows for the capture of specific emission lines (like Hydrogen Alpha and Oxygen III from the L-Extreme) and complementary details (from the Askar D2), all while incorporating the natural color of the stars.

The Equipment Behind the Shot

Achieving such a detailed image requires a robust setup. Here's the equipment that made this shot possible:

• Telescope: Skywatcher 150PDS
• Camera: ToupTek ATR585C
• Mount: Proxisky UMI 17R
• Filters: Optolong L-Extreme + Askar D2
• Guiding: Askar OAG + ZWO ASI220MM Mini
• Accessories: Askar Filter Drawer, QHY Focuser, Mele Quieter 3, Pegasus Powerbox

The Art of Processing

The processing pipeline is as crucial as the acquisition. This image was meticulously processed in Pixinsight, with final touches in Gimp. The workflow included:

1. Separate Stacking: Stars, L-Extreme, and Askar D2 data were stacked independently.
2. Alignment: Crucial for combining the different datasets accurately.
3. Gradient Removal: Using Graxpert to clean up background gradients.
4. SPCC: For color calibration.
5. Channel Separation: Dividing the L-Extreme and Askar D2 data into Sii, Ha, and Oiii channels.
6. Noise and Blur Reduction: Employing BlurX and NoiseX.
7. Star Manipulation: Using StarX for selective star processing.
8. SHO Combination: Merging the narrowband channels to create the signature false-color representation.
9. Narrowband Normalization: Balancing the narrowband signal.
10. Selective Color Correction: Refining the color balance.
11. Sharpening: Enhancing fine details.
12. Minor Corrections: Further adjustments made in Gimp.
13. Star Treatment: Stretching and saturation adjustments for the stars.
14. Final Combination: Integrating the processed nebula with the enhanced stars.

This comprehensive approach showcases the dedication and skill involved in modern astrophotography, resulting in a truly beautiful and scientifically informative image.