Join Jan Kabili for an in-depth discussion in this video Creating and editing adjustment layers, part of Photoshop CS4: Image Adjustments in Depth.
Adjustment layers are the most flexible way to correct the colors and tones in an image. Most of the commonly used Photoshop image adjustments like Levels and Curves and Black and White and about a dozen more can be applied as adjustment layers. So what exactly is an adjustment layer and how do you make one? To show you that, I have my Adjustments panel open and I have my Layers panel open, and in the Layers panel you can see there are two layers in this file. I'm going to make the photo layer temporarily invisible so you can see that on the lizard layer, there is just this little lizard surrounded by transparent pixels. I'll make the photo layer visible again and turn the lizard layer off, so that you can see that the photo layer has this photo of a garden wall.
And I'll make both of those layers visible again. The first step in adding a new adjustment layer is to select whichever layer you would like to have the new adjustment layer come in above. I'd like this adjustment layer to affect both the lizard and the photo layers. So I'm going to select the lizard layer here in the Layers panel. Then I'm going to add an adjustment layer. If you've created adjustment layers in previous versions of Photoshop, you probably did that by going down to the Black and White icon called the Create New Fill and adjustment layer icon at the bottom of the Layers panel and clicking there and choosing one of the adjustment layer flavors from here.
You can still do it this way, but in Photoshop CS4 there is another and I think more direct way of applying an adjustment layer and that's from the New Adjustments panel. So I'm going to exit out of this menu without choosing an adjustment and I'm going to go up to the Adjustments panel. At the top of the Adjustments panel, there are 15 icons that represent the 15 different kinds of adjustment layers. If I move my mouse over any one of these, I see its name at the top of the Adjustments panel. I'm going to go over to the first icon, the Brightness/Contrast icon, and I'm going to click on that icon and that adds a new Brightness/Contrast adjustment layer in the Layers panel. I know this is an adjustment layer, because unlike a regular pixel-based layer, this adjustment layer has two thumbnails on it.
The thumbnail on the left is the thumbnail that represents the adjustment and sometimes, by the way, this may look like a generic icon, if you don't have a lot of room in your Layers panel. There is a also a layer mask thumbnail on this adjustment layer, because each adjustment layer comes with a layer mask that you can use to limit where the adjustment applies in the image, this I'll show you how to do in a later movie. When I clicked the Brightness/Contrast adjustment layer icon, not only did I get a new adjustment layer in the Layers panel, but the Adjustments panel changed too to display the controls for the Brightness/Contrast adjustment.
That's different than in previous versions of Photoshop where each adjustment had its own dialog box. Now all of the controls always appear here in the Adjustments panel when an adjustment layer is active. I can use these controls to tweak the appearance of the image. So, for example, if I want this image to be brighter, I'll click on the Brightness slider and I'll drag to the right. You can see that both the lizard on the lizard layer and the photo on the photo layer have gotten brighter. Because, by default, an adjustment layer affects all of the visible content on the layers beneath it.
One important quality of an adjustment layer like this one is that it does not directly change the image pixels. So if I were to come in and make the Brightness/Contrast adjustment layer temporarily invisible, by clicking its eye icon, you can see that I still have that same dark image on the lizard and photo layers below. This nondestructive quality of adjustment layers is really important, because it means that you are protecting your original image so that you always have access to it. That's true even if you save the image, close it, and then reopen it as long as you've saved it in a format that retains layers like the .PSD or Photoshop Document format, the TIF format or the Photoshop PDF format.
I'm going to turn this Brightness/Contrast adjustment layer back on, by clicking in its visibility field, so that I can show you that you can have more than one adjustment layer in an image. To add another adjustment layer, I need to get back to Icon view in the Adjustments panel. I can do that with the Brightness/ Contrast 1 layer selected by going to the bottom of the Adjustments panel and clicking on this green arrow. Back here in Icon view of Adjustments panel, I could choose a different adjustment this time. For example, I think, I'll apply a Black and White adjustment by clicking on this icon right here and that converts the image to black and white.
It brings up the controls for the Black and White adjustment layer here in the Adjustments panel, and you can see that there is a new adjustment layer in the Layers panel, the Black and White 1 adjustment layer. One of the great things about adjustment layers is that they remain editable, and that means that I can go back at any time and tweak the settings for an adjustment layer. So now that I've converted this image to Black and White, I can see that I'd like it to be a little bit brighter. So I can go back to the Brightness/Contrast adjustment layer by selecting it in the Layers panel, and that brings up the Brightness/Contrast settings for that particular adjustment layer.
And here, I could come up to the Brightness slider and I could drag it further to the right or I could add contrast to the image by clicking on the Contrast slider and dragging it to the right. By the way, contrast means the difference between the light tones and the dark tones in an image. I've mentioned some of the unique qualities of adjustment layers, but in other ways, adjustment layers behave just like regular layers. You've already seen that I can make an adjustment layer temporarily invisible by clicking its eye icon. I also can change the stacking order of adjustment layers. So, for example, if I click-and-drag the Brightness/Contrast 1 adjustment layer to the top of the layer stack and release my mouse when the border above the Black and White adjustment layer turns bold, you'll see a slight change in the image, because adjustment layers affect not just regular layers beneath them, but also other adjustment layers that are beneath them.
I can also change the Opacity of an adjustment layer. So with this Brightness/Contrast 1 adjustment layer selected in the Layers panel, I could go up to the Opacity field, click on the arrow to the right of it and drag the slider to the left to slightly reduce the strength or Opacity of the Brightness/Contrast adjustment layer. Similarly, I could change the layer blend mode of the adjustment layer from this menu or I could even delete an adjustment layer by selecting it in the Layers panel and then pressing the Delete key on the Mac or the Backspace key on the PC.
Now that you know what adjustment layers are and how to create and edit them, I hope you'll get in the habit of using adjustment layers. If you're still using direct adjustments instead, you're missing the important advantages that adjustment layers offer, which I'm going to spell out for you in more detail in the very next movie.
- Using adjustment layers in a non-destructive image-editing workflow
- Correcting color with curves
- Adjusting brightness and contrast with levels
- Dodging and burning photographs
- Reading histograms accurately
- Converting color images to grayscale with a Black & White adjustment layer
- Customizing auto-corrections for more accurate quick adjustments