What You Can Do with Adjustment Layers
Adjustment layers are one of the most important types of layers. Their big benefit is that you can adjust them at any time you like. For example, suppose your Curves adjustments look perfect when you apply them right after they come out of Camera Raw. However, after changing the Hue and Saturation on another layer, adding some brushstroke effects, and then adding an overall Solid Color layer, you then need to change the contrast in certain brightness levels of the original image. No problemjust double-click on the Curves icon in the Curves Adjustment layer and the Curves dialog opens to allow you to make any changes. You could even make some radical changes by changing the layers blend mode.
Adjustment layers are created by choosing them from the Adjustment layers menu at the bottom of the Layers palette. Adjustment layers do exactly the same thing as the commands of the same name under the Image
Brings up the standard Color Picker dialog and lets you pick any color in the palette. As soon as you click OK, the layer is filled with that color. You may then apply any of the Blend Modes to that layer for a blended color effect. You could also experiment with the Fill and Opacity sliders for even more variety. Try Darken, Lighten, Hue, Saturation, and Soft Light.
Fills the layer with any gradient in the Gradient's palette. You can even make your own. The layer is opaque, but like Solid Color, you can use Blend Modes and the sliders to create a wide variety of effects.
Fills your image with any pattern you've made or any of the dozens of patterns that come with Photoshop. Used with colored and textured paper patters, this can be a great way to make an aged photo. Use the Overlay mode. Also, feel free to experiment. Different colors in the image will blend differently with different colors in the patterns.
Ensures that the white, black, and midpoints of brightness range are set properly. You can also set color balance by adjusting individual channels. If this layer is masked, it can be used to control tint in specific areas of the image.
Controls contrast in specific ranges of brightness. Very useful when masked for setting contrast to targeted areas of the image.
Corrects color balance, unless you had a color or grayscale card in the picture (see the "Shooting a Calibration Target or Gray Card" section in Chapter 2).
Changes the layer or targeted area's brightness, darkness, and contrast but has very little control over interpretation. Can be useful as a quick way to darken or lighten an area, such as the periphery of a vignette.
There are actually three sliders in this layer. Hue lets you interactively change the overall tint of the image. If you exaggerate the Hue setting, you can even create something that looks like a tinted photo. Adjusting Saturation affects the intensity of the colors; if you remove all saturation you'll have a monochrome. Lightness just makes the image lighter or darker.
Helps prepress folks adjust the amount of process colors to be dedicated to any primary color, which ensures the final output turns out as expected.
Creates special color effects.
Creates various color effects. This is an amazing tool for creating psychedelic-toned color effects, monotones, and duotones. The effect you get is completely dependent on the gradient used. The tones on the left end replace the shadow tones, and those on the right replace the highlights. So, for instance, if you had a gradient that went from white to black, you'd get a negative image. You could vary tones with the smoothness of the gradient, too. Experiment with a few of the standard gradients. Then, based on what you learn, make and save some gradients of your own.
The standard photo filters used in color photography, as well as some standard black and white filters. To get the same effect with the black and white filters as you would with black and white film, create a Hue/Saturation layer clipped to the Photo Filter layer, then drag the Saturation slider all the way left.
Switches the image from positive to negative.
Sets a brightness point at which colors fall on one side or the other of the black/white dividing line.
Lets you limit the number of shades of color and brightness in the image with a result that looks a bit like a hard-edged and flat-color poster.