There are several adjustments that affect the saturation of an image, and in this lesson we’ll discuss two. As always in this book, you’ll learn the foundations and rationale here and then you can deepen your knowledge in the Compendium. For this lesson, the good parts to reference are “Vibrance” (page 237) and “Hue/Saturation” (page 238).
Picture the light from a laser. No matter what color it is, it’s impressively intense and vibrant—in fact, its color is purely of one wavelength. That would be the ultimate saturated color. The color of an old incandescent bulb is smeared out a bit around various yellows, reds, and oranges. Since it’s not as pure a hue as the laser, we’d say it’s less saturated. Full spectrum lights produce a color of light that is pretty much completely unsaturated: all the visible hues are blended together as white light. So, saturation is a measure of the purity of a hue.
An image with no saturation is grayscale. Each hue in a heavily saturated image is pure but without gradation of color. We call this “color clipping,” and it’s generally avoided. It can also occur when outputting an image: depending on the settings used, colors that didn’t clip on screen may clip in print, or colors that aren’t clipped on one display may clip on another.
The Vibrance adjustment has two sliders: Vibrance and Saturation. The Hue/Saturation adjustment also has a Saturation slider, but it behaves (I’d say misbehaves) very differently from the identically named one in the Vibrance adjustment. Let’s try them both. We’ll use the same image so you can compare.
The Vibrance slider more strongly affects the least saturated colors so it avoids clipping colors that started out more intense. It also avoids oversaturating skin tones. The Saturation slider is much stronger but shows some restraint. When lowered, it can remove all color from the image. This is also true with the Hue/Saturation adjustment with which users customize grayscale conversions. Or they used to until the Black & White adjustment was made for exactly that approach.
Double-clicking the name (label) of a slider resets that control to 0.
By increasing the Saturation and reducing the Vibrance, you can remove color from nearly neutral areas. Note here how the yellowed white stone is made to look cleaner while the red and blue areas mostly retain their color.
This adjustment can affect saturation, as you would guess, but it can also shift hue and affect lightness (tone) in an image. Remember the color wheel we saw earlier? Shifting hue means giving that wheel a turn—either slightly or drastically. Let’s experiment a bit, then we’ll do something practical.
Please note that dragging it either way to the end gets you to the same place: the other side of the color wheel! The numbers are a hint too: 180 or -180, as in 180º. Watching the color strips at the bottom of the panel is helpful to see how the current hues (top strip) become shifted to the hues directly below them. Each strip is essentially a color wheel snipped and flattened.
If you aren’t impressed yet, that’s alright. There’s a really cool feature that you may find more exciting. You can adjust these attributes for each hue. That is, you can adjust the hue, saturation, and/or lightness of just blues, for example. Let’s do that.
Note the menu with the word Master chosen and the small pointing hand to its left. These are two ways of choosing the hue you want to adjust. The menu seems fairly straightforward: if you want to adjust blues, you choose Blues from the menu.
That little hand resembles a scrubby cursor, the one you see when you hover over a field’s label. Just hover the cursor over the word “Hue” or “Saturation” to see what I mean. Well, this tool can be used like that.
The blues in the image don’t exactly correspond to Photoshop’s definition of blue. (On Photoshop’s color wheel, blue is at the angle of 240º. That will be useful knowledge soon.) But let’s continue for a moment as if our blues are their blues.
As long as what you press and drag on has a hue within Photoshop’s defined range for that hue, this will work. Dragging on a reddish pixel will change which hue you’re adjusting entirely.
To precisely target the right range of hues for the image, there’s another tool to enlist: the Hue sampler. It’s the first eyedropper near the bottom of the Properties panel.
The Adjusted Hue Indicator (officially, another thing called the Hue slider) has shifted to the left, closer to cyan. If it’s wrapping around to the other end, ⌘/Ctrl-drag the hue strips to offset them. The central part of that indicator is under the hues that will be fully adjusted, the outer parts are under those hues that will be partially adjusted. The numbers above the hue strips show the exact hue angles on the color wheel that are being affected. Check out the diagram above.
If you’d like to learn even more about this adjustment, see “Hue/Saturation” (page 238). Yes, there’s more! In fact, now that you understand the approach to using adjustment layers, you can explore the other adjustments too. Use the “Adjustments & Color” chapter of the Compendium as your guide.
To affect only some areas of an image and not others requires us to make selections and masks. So you won’t be surprised when you turn the page and see what’s up next.