Capturing the North America Nebula (Caldwell 20) with a New Dual-Band Filter
Astrophotography is a journey of constant learning and experimentation. Recently, I had the opportunity to test out a new piece of equipment: the SV220 dual-band filter. The goal was to see how it would perform when mounted to the front of my camera lens, even with a full moon and Bortle 7 skies. The target for this test? The magnificent North America Nebula, also known as Caldwell 20.
The Challenge and the Setup
Mounting a filter to the front of a camera lens can present its own set of challenges, especially when it comes to achieving focus. I used step-down rings to securely attach the SV220 filter. To my delight, I found that I could achieve focus manually and even utilize N.I.N.A.'s canon lens autofocus plugin. While my polar alignment wasn't perfect – a deliberate choice as the primary focus was on testing the filter and focusing – the results were still promising.
Equipment Used:
- Camera: Canon Rebel T2i (modified)
- Lens: Canon 55-250 mm IS II
- Filter Mounting: Step-down rings to mount SV220 to the front of the lens
- Mount: Sky Adventurer GTi
- Tripod: iOptron Tripod
- Control: Laptop running N.I.N.A.
Processing:
The single, 60-second exposure was processed using a combination of software to bring out the detail:
- Pixinsight: Stretching, background neutralization, and noise reduction.
- GraXpert: Further noise reduction.
The Results
Despite the less-than-ideal conditions, the SV220 dual-band filter proved its worth, allowing for the capture of the distinct shape and hydrogen-alpha emission of the North America Nebula.
This test was a valuable learning experience, showcasing the adaptability of the equipment and the potential of the new filter. I'm excited to explore further possibilities with the SV220 under darker skies!
