Selecting the Contents of Layers

A few sections back, I mentioned that every layer (except the background) includes a transparency mask. This mask tells Photoshop which pixels are opaque, which are translucent, and which are transparent. Like any mask, Photoshop lets you convert the transparency mask for any layer — active or not — to a selection outline. In fact, you use the same keyboard techniques you use to convert paths to selections (as explained in Chapter 8) and channels to selections (Chapter 9):

♦ Ctrl-click an item in the Layers palette to convert the transparency mask for that layer to a selection outline.

♦ To add the transparency mask to an existing selection outline, Ctrl+Shift-click the layer name. The little selection cursor includes a plus sign to show you that you're about to add.

♦ To subtract the transparency mask, Ctrl+Alt-click the layer name.

♦ And to find the intersection of the transparency mask and the current selection outline, Ctrl+Shift+Alt-click the layer name.

If you're uncertain that you'll remember all these keyboard shortcuts, you can use Select ^ Load Selection instead. After choosing the command, select the Transparency item from the Channel pop-up menu. (You can even load a transparency mask from another open image if the image is exactly the same size as the one you're working on.) Then use the Operation radio buttons to merge the mask with an existing selection.

Selection outlines exist independently of layers, so you can use the transparency mask from one layer to select part of another layer. For example, to select the part of the background layer that exactly matches the contents of another layer, press Shift+Alt+[ to descend to the background layer and then Ctrl-click the name of the layer you want to match.

The most common reason to borrow a selection from one layer and apply it to another is to create manual shadow and lighting effects. After Ctrl-clicking on a layer, you can use this selection to create a drop shadow that precisely matches the contours of the layer itself. No messing with the airbrush or the lasso tool — Photoshop does the tough work for you.

Now, you might think with Photoshop 6's extensive range of layer styles, manual drop shadows and the like would be a thing of the past. After all, you have only to choose Layers Layer Styled Drop Shadow and, bang, the program adds a drop shadow. But the old, manual methods still have their advantages. You don't have to visit a complicated dialog box to edit a manual drop shadow. You can reposition a manual shadow from the keyboard, and you can expand and contract a manual shadow with more precision than you can an automatic one.

On the other hand, this is not to say the old ways are always better. A shadow created with the Drop Shadow command takes up less room in memory, it moves and rotates with a layer, and you can edit the softness of the shadow long after creating it.

What we have is two equally powerful solutions, each with its own characteristic pros and cons. Therefore, the wise electronic artist develops a working knowledge of both. This way, you're ready and able to apply the technique that makes the most sense for the job at hand.

The following sections explore the manual drop shadows, highlights, and spotlights. For everything you ever wanted to know about the Layer Styles commands, read Chapter 14.

Learn Photoshop Now

Learn Photoshop Now

This first volume will guide you through the basics of Photoshop. Well start at the beginning and slowly be working our way through to the more advanced stuff but dont worry its all aimed at the total newbie.

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