Iris Nebula (NGC7023)

Buy a Print This combined image was made by stacking luminance frames at 2 different exposures for the background plus a third, shorter exposure just for the bright central region. The red, green and blue frames were then stacked and combined in the usual way, but filtered more than usual to remove noise. Finally, the color image was blended with the luminance image using Photoshop’s “color” blend mode. This produces an image that gets its sharpness from the luminance frames, with minimal color noise. The nebula is about 1,300 light years from Earth in the constellation Cepheus. It was captured […]