Observation by David Davies: M1, The Crab Nebula

Uploaded by

David Davies

Observer

David Davies

Observed

2022 Mar 07 - 22:01

Uploaded

2022 Mar 15 - 13:09

Objects

The Crab Nebula (M1)

Equipment
  • 8-inch Ritchey-Chretien
  • Skywatcher EQ8 mount
  • QSI 683 camera
Exposure

25 x 5-min lum, 15 x 5-min RGB

Location

Cambridge, UK

Target name

M1, The Crab Nebula

Title

M1, The Crab Nebula

About this image

I've returned to the Crab Nebula as part of understanding the imaging differences between my one-shot ASI 294MC Pro camera and my QSI 683 mono camera with Astrodon filters.

The 294 camera produces a pleasing image, but the HII regions are very weak and rendered orange rather than red. I suspect that this is due to the green pixels having significant sensitivity at the red end of the spectrum and capture these HII regions as being partly green in colour. Hence the 'orange' rendering of the HII red.

By contrast, the HII tracks are rendered red in this image as the Astrodon filters have very sharp cut-offs between the colours.

I think the Crab Nebula is a tricky target. Although it is quite bright, it is relatively large, so the surface brightness is low. So you need lots of data to bring out the detail.

I was plagued by hazy skies and the luminance data, in particular, was barely useable. Nonetheless, it is quite a pleasing image, and I've tried to hold back the temptation to pop up the colours. The presented image is very much how it came out of PixInsight's Photometric Colour Calibration tool.

 

Files associated with this observation
Like this image
Copyright of all images and other observations submitted to the BAA remains with the owner of the work. Reproduction of work by third parties is expressly forbidden without the consent of the copyright holder. By submitting images to this online gallery, you grant the BAA permission to reproduce them in any of our publications.