Guy kindly shared his process for creating this beautiful image of the galaxy M74...

To start:

• For the integration and processing I used PixInsight
• I combined the RGB image as usual, except I used the V files to add to the G channel

Processing:

• I aligned each channel and stacked them
• I then stacked the 3 channels into a single colour image
• Next I cropped the image to remove artifacts present on the edge of the image
• I then used DBE (Dynamic Background Extraction) to remove the background gradient
• Next is colour calibration and then the image is then stretched
• I decided to do a HDR Multiscale Transformation to reveal some of the inner structure that would otherwise be overexposed

Noise reduction:

• Setting the blackpoint of the image (not too harshly)
• I used a masked saturation boost to enhance the colour
• Finally I removed green from the image as that doesn't really look that natural in this case

Photoshop:

• I balanced the colour a little and sharpened the image a little too

This process took Guy around 15-20 minutes.