What is a luminosity mask?
I love luminosity masks (also known as luminance range masks) - it’s my favorite type of mask. They are incredibly flexible and powerful, and give you amazing control over your edit. I use them all the time. Years ago when I was beginning to learn about masking, I admit to being intimidated by them. It sounds so complicated! But really, it’s not that hard.
Most of the other common mask types (brush, radial gradient, linear gradient) allow you to create a mask in a part of the photo that you select - like a foreground, a sky, or just some general area that needs an adjustment. It’s sort of like picking a geographic area of the photo - your mask covers everything in the selected area. That selected area could contain a mix of Highlights, Midtones and Shadows because you are choosing the entire section. And yes, these masks are really useful too - I use them a lot. But oftentimes, a luminosity mask is a better way to make a selection.
So then what is a luminosity mask, you ask? Well, it’s a mask based on light values, not “real estate”. These allow you to isolate specific tonal ranges, such as Highlights, Midtones, or Shadows - regardless of where they are in the image - and create a mask just for them. This gives you so much control over your edit, which is essential when you are trying to achieve a balanced look in your edits. It’s a great way to apply subtle adjustments to an image.
When you think about it, a photograph is just a collection of light, right? So these masks make sense for that reason. When editing, if you apply a color adjustment (for example) across the entire image, it can look over-saturated and unnatural. Using a luminosity mask lets you control which specific tonal areas in the photo where that color impact will display. You can apply it more gently and subtly in the Highlights and Midtones, for example, with a luminosity mask and a generous gradient edge.
If you haven’t learned how to use them, I cover this topic in a lot of videos and highly recommend you experiment until you get the hang of it. You’ll be glad you did! Want to learn more? Subscribe to my YouTube channel:
