A New Dawn for Deep Sky Imaging: North American Nebula in Glorious SHO

Four months into my astrophotography journey, I've taken a significant leap forward by investing in a monochrome camera system. This includes a dedicated filter wheel, electronic focuser, and the highly sought-after LRGBSHO filters. The results of this upgrade are truly breathtaking, and my first light with this new rig has been on the iconic North American Nebula, a celestial landmark I previously captured at a lower focal length.

From OSC to Monochrome: A Leap in Detail and Color

Having previously shot the North American Nebula at 135mm with an OSC (One-Shot Color) camera, I was eager to see the difference a monochrome setup would make. I must say, I am incredibly impressed with the results. The level of crispness and detail is phenomenal. Color management has become remarkably straightforward, and the SHO (Sulfur, Hydrogen, Oxygen) color palette offers a richness and vibrancy that was simply unattainable with my previous dual-band Ha-OIII filters. The flexibility to capture both SHO data for the nebula and RGB data for the stars in the same session is a game-changer.

The Rig Behind the Spectacle

Achieving these results required a specific set of equipment, carefully chosen to maximize performance, especially under challenging Bortle 8 skies:

• Mount: Skywatcher 150i Wave mount
• Telescope: Askar SQA55 f/4.8
• Camera: Touptek ATR585M (Gain 100, Offset 50, Cooled to -10°C)
• Filters: Touptek 36mm SHO and RGB filters

Data Acquisition and Integration

The imaging session was meticulously planned to gather sufficient data for both the nebulosity and the stars:

• Nebulosity: 44 subs of 300s SII, 23 subs of 300s Ha, and 44 subs of 300s OIII. This amounts to approximately 8 hours and 35 minutes of integration time for the narrowband data.
• Stars: 60 subs of 10s each for R, G, and B channels.

All of this was captured under Bortle 8 skies, demonstrating the power of dedicated narrowband imaging and careful processing.

Post-Processing Alchemy: Pixinsight and Lightroom

The raw data was transformed into the stunning image you see today through a rigorous post-processing workflow:

• Stacking: 2x drizzle stack (Square function with 0.7 drop shrink size)
• Noise Reduction & Sharpening: BlurXterminator, NoiseXterminator
• Stretching: SetiAstro Statistical stretch
• Star Handling: StarXterminator
• Color Calibration: Narrowband renormalization
• Final Adjustments: Curve transformation, Lightroom enhancements
• Composition: Recomposition of elements as needed.

This process highlights the rewarding, albeit sometimes challenging, nature of processing monochrome data. It's a journey of relearning and refining techniques, but the results speak for themselves. The sheer beauty and detail captured in the North American Nebula and the intricate structures of the Cygnus Wall are a testament to the advancements in modern astrophotography equipment and techniques.