Adobe Photoshop CS5 for Photographers - Martin Evening [202]
Figure 9.12 Text layers are created whenever you add type to an image. Text layers can be re-edited at any time.
Adjustment layers
Adjustment layers are image adjustments in the form of layers. With adjustment layers you have the opportunity to edit the adjustments as often as you like, plus you can toggle an adjustment on or off by clicking the layer eyeball icon (Figure 9.13). The chief advantages of working with adjustment layers are that you can re-edit the adjustment settings at any time and you can use the paint, fill or gradient tools to selectively apply the adjustments to an image.
Figure 9.13 Adjustment layers are image adjustments that can be placed within an image and applied to individual or multiple layers. Like other layers, you can mask the contents and adjust the blending mode and layer opacity.
Layers panel controls
Figure 9.14 provides an overview of the Layers panel controls for the layered image shown in Figure 9.15. The blending mode options determine how a selected layer will blend with the layers below, while the Opacity controls the transparency of the layer contents and the Fill opacity controls the opacity of the layer contents independent of any layer style (such as a drop shadow) which might have been applied to the layer. Next to this are the various layer locking options. At the bottom of the panel are the layer content controls for layer linking, adding layer styles, layer masks, adjustment layers, new groups, and new layers, as well as a Delete Layer button. Most of the other essential layer operation commands are conveniently located in the Layer panel fly-out options.
Figure 9.15 Here is an expanded diagram of how the layers in a magazine cover image file were arranged inside Photoshop. The checkerboard pattern represents transparency and the layers are represented here in the order they appeared in the Layers panel.Client: Goldwell Professional Haircare.
Layer visibility
You can selectively choose which layers are to be viewed by selecting and deselecting the eye icons. If you go to the History panel options and check ‘Make Layer Visibility Changes Undoable’, you can even make switching the Layer visibility on and off an undoable action.
Layer styles
You can use the layer style menu at the bottom of the Layers panel (see Figure 9.14) to apply different types of layer styles to an image, shape or text layer. This feature is really of more interest to graphic designers rather than photographers, but you'll find descriptions of the various layer styles in the DVD Help Guide.
Figure 9.14 This is an overview of the Photoshop Layers panel. See also the diagram in Figure 9.15 which shows how this layered image appeared as a final composite.
Adding layer masks
You can hide the contents of a layer either wholly or partially by adding a layer mask, a vector mask or both. Masks can be applied to any type of layer: image layers, adjustment layers, type layers or shape layers. Image layer masks are defined using a pixel-based mask, while vector masks are defined using path outlines. Click once on the Add Layer Mask button to add a layer mask and click a second time to add a vector mask (in the case of shape layers a vector mask is created first and clicking the Add Layer Mask button adds a layer mask). You will also notice that when you add an adjustment layer or fill adjustment layer a layer mask is added by default. The layer mask icon always appears next to the layer icon and a dashed stroke surrounding the icon tells you which is active (see Figures 9.16 and 9.17).
Figure 9.16 The Layers panel view shown here contains two layers, and the selected layer is the one that's highlighted here. The dashed border line around the layer mask icon indicates that the layer mask is active and any editing operations will be carried out on the layer mask only. There is no link icon between the image layer and the layer mask. This means that the image layer or layer