Beginning astroimagers want results, and that means colorful images. Unfortunately, that doesn’t happen quickly. So, this column is about the foundations of blending color.
The best way to create a colorful image is by working on a color layer that is independent of a “properly prepared” luminance layer, which I’ll discuss in a future column. The color layer is not scaled or stretched and opens looking dark in Photoshop
(image #1). Paste the luminance layer above the color layer so that the conversion from a grayscale image to an RGB image happens automatically. Blend the luminance layer with the color layer using the “Luminosity” mode.
Astronomy magazine subscribers can read the full column for free. Just make sure you're registered with the website.