Capturing the Crescent Nebula: A Bortle 4 Gem with Sony a6400 and NexStar 8SE

Astrophotography is a journey into capturing the ethereal beauty of the cosmos, and sometimes, the right combination of equipment and clear skies can yield truly breathtaking results. Today, we're diving into an incredible capture of NGC 6888, famously known as the Crescent Nebula.

This stunning image was brought to life using a Celestron NexStar 8SE telescope paired with a Sony a6400 camera. Shot under the favorable conditions of a Bortle 4 sky, this capture showcases the power of dedicated equipment and skillful processing.

The Technical Details Behind the Shot

The astrophotographer shared the detailed breakdown of their setup and process, offering valuable insights for fellow enthusiasts:

• Object: NGC 6888 – Crescent Nebula
• Integration Time: 150 x 60s = 2.5 hours
• Telescope: Celestron NexStar 8SE with f/6.3 focal reducer
• Camera: Sony a6400 (unmodified)
• Mount: Celestron Alt-Az Wedge (w/ tracking)
• Filter: Celestron 2" UHC
• Guiding: ZWO ASI120MM + 30mm guide scope using PHD2
• Acquisition: NINA
• Stacking: Siril
• Processing: Photoshop
• Sky Quality: Bortle 4

Insights from the Capture

The notes from the astrophotographer highlight a few key points about this particular capture:

Captured under darker skies with an OSC camera and UHC filter. Despite the relatively short sub-exposures (60s), the faint oxygen-rich shell and shock front detail around WR 136 came through beautifully after careful stretching and star reduction in post. Slight softness due to seeing and some guiding error, but overall thrilled with how well the UHC handled this emission-rich region.

The use of a UHC (Ultra High Contrast) filter is particularly noteworthy for emission nebulae like the Crescent Nebula, as it helps to isolate the light emitted by ionized oxygen and hydrogen, thereby enhancing the nebula's structure and color against the background sky.

Even with some minor challenges like seeing conditions and guiding, the result is a testament to the power of post-processing in bringing out the hidden details within astronomical data. The faint oxygen-rich shell and shock front around WR 136 are rendered with impressive clarity.

This capture serves as an excellent example of what can be achieved with a well-matched telescope and camera system, combined with careful planning and execution. It's inspiring to see such beautiful results emerging from the passion of astrophotography!