Capturing the Dazzling Pleiades: A Bortle 3 Gem
Welcome back to the blog! Today, we're diving into the celestial beauty of the Pleiades star cluster, also known as M45. This iconic open cluster, often referred to as the Seven Sisters, is a breathtaking sight in the night sky, and capturing it from a Bortle 3 dark sky zone truly brings out its intricate details.
The Gear and the Dark Skies
This stunning capture was made possible with a fantastic combination of equipment:
- Camera: Canon Rebel T7
- Telescope: Redcat 51 WIFD
- Mount: iOptron Skyguider Pro
Crucially, the observing location was a Bortle 3 zone. For those unfamiliar, the Bortle Scale is a measure of light pollution, with Bortle 1 being the darkest possible. Bortle 3 skies offer a significant advantage for astrophotography, allowing fainter details to emerge and dramatically improving the signal-to-noise ratio.
The Data Acquisition
To build this image, a solid set of data was collected:
- Lights: 120 frames, each exposed for 60 seconds at ISO 1600.
- Darks: 30 frames.
- Flats: 30 frames.
- Bias: 30 frames.
This methodical approach ensures the best possible data for post-processing.
The Processing Workflow
Post-processing is where the magic truly happens. The workflow for this image involved a multi-stage approach:
- Stacking: The initial stacking of the light, dark, flat, and bias frames was performed in Affinity Photo 2. While Siril is a powerful tool for stacking, the user opted for Affinity Photo 2 due to disk space limitations on their older MacBook during the stacking process.
- Color Calibration and Stretching: Siril was then employed for essential color calibration, stretching the data to bring out the details, and saturation adjustments.
- Refinement: Finally, the processed image was moved back into Affinity Photo 2 for critical tasks such as background removal, star reduction to manage their size and intensity, and denoising to clean up any remaining noise.
This careful sequence of steps allowed the inherent beauty of the Pleiades to be revealed, resulting in the spectacular image you see above.
Why Not Stack in Siril?
A common question that arises is why not complete the entire stacking process within Siril. For many, Siril is the go-to for its robust stacking capabilities. However, Siril can consume a significant amount of disk space during the stacking process, especially with large datasets. This was a limiting factor in this instance, prompting the use of Affinity Photo 2 for the initial stacking phase. For those facing similar challenges, upgrading storage solutions can be a cost-effective way to leverage powerful software like Siril to its full potential.
This image is a testament to what can be achieved with the right equipment, a dark sky location, and a well-thought-out processing pipeline. Keep looking up!
