Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
Luminance, also known as tone is the brightness of a pixel. Luminance is measured in steps known as levels. In an everyday average RGB image, which is far in a way the most common kind of image you'll encounter, a level of 0 is black and a level of 255 is white. The other levels 1 through 224 are shades of gray in between. So where does color come in? Again, assuming an RGB image, you have three luminance-only versions of the image called channels.
The three channels are respectively colorized red, green and blue, hence RBG, and then blended together to produce the full color composite. In other words, color is a function of luminance. Meanwhile, luminance and color sometimes react with each other in surprising ways. Look at a strip of gray values and you see a steady progression of neutral levels just as you would expect. Throw in a cool color like blue, and the blues go from light to dark again as expected.
But add a warm color like red and we go from these pinks at the top to a surprisingly intense scarlet near the bottom. Then as we progress into the oranges, notice how the most vivid colors move up the list. We eventually arrive at yellow, which darkens into a muddy, somewhat unappetizing green. In other words, changing the brightness of a photo can be tricky. The purpose of this chapter is to show you how to adjust luminance in ways that make your images look always better and never worse.
I'll start by explaining channels so you can see how luminance and color work together. Next, I'll show you Photoshop's Automatic Luminance Correction functions, and then we'll take a look at two commands that put you in control, Brightness Contrast and Shadows Highlights. In the end, I think you'll be amazed at the degree to which you can rescue even the most washed-out or gloomy looking image.
Get unlimited access to all courses for just $25/month.Become a member
Access exercise files from a button right under the course name.
Search within course videos and transcripts, and jump right to the results.
Remove icons showing you already watched videos if you want to start over.
Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.
Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.