Photoshop is an extremely intricate program for which there is a multitude of ways to accomplish any one task. Nonetheless, one of the most fundamental techniques almost every photographer should know is how to create and use luminosity masks. This great video tutorial will show you how to use them.
Coming to you from Nathaniel Dodson with tutvid, this helpful video will show you all about luminosity masks in Photoshop and why they are so useful. Luminosity masks are so helpful because they allow you to create layer masks that are derived from the luminosity values in a photo. In other words, this could allow you to create a layer mask that selects only the highlights of an image and then easily blend something like a color toning effect into them or to add an adjustment of some sort to only the shadows and have it gradually blend into the midtones for a realistic transition. The best part is that they're very easy to generate quickly, making them an extremely powerful editing tool for many genres of photography that is often far more efficient than using some other sort of masking technique. Check out the video above for the full rundown.