Real World Adobe® Photoshop® CS2 [Electronic resources] : Industrial-Strength Production Techniques نسخه متنی

Navigation

In this section, we first explore some of the fastest ways to move around your image, including zooming in and out. Then we discuss moving pixels around both within your document, and from one document to another. It's funny, but we find that even expert users forget or never learn this basic stuff, so we urge you to read this section even if you think you already know all there is to know about navigating in Photoshop. And as usual, Photoshop CS2 snuck in some new zoom and scroll tricks.

Magnification

Images got pixels. Computer screens got pixels. But how does one type of pixel relate to the other type of pixel? When you display an image on your screen, Photoshop has to match the image pixels to screen pixels (see Figure 2-2). The percentage in the title bar of the document window tells you how Photoshop is matching up those pixels.

The key to understanding this percentage stuff is to remember two things. First, at 100-percent view (otherwise known as Actual Pixels), each image pixel is represented by a single screen pixel. This view has nothing to do with how big the image will appear in print (or even on the Web, because different monitors have different resolutions). Second, at any percentage other than 100, you're probably not seeing a fully accurate view of your image.

At 400 percent, the image is magnified four times. At 50 percent, it's reduced by half, so you're only seeing half the pixels in the image because you're zoomed farther out and Photoshop has to downsample the image on the fly. When you're viewing at an integral multiple of 100 (25, 50, 200, 400 percent, and so on), Photoshop displays image pixels evenly. At 200 percent, four screen pixels (two horizontal, two vertical) equal one image pixel; at 50 percent, four image pixels equal one screen pixel, and so on.

However, when you're at any "odd" percentage, the program has to jimmy the display in order to make things work. Photoshop can't cut a screen pixel or an image pixel in half, so instead it fakes the effect using anti-aliasing. The moral of the story is, always return to Actual Size (100 percent) view to peruse your image.

By the way, while it's tempting to select Print Size from the View menu (in order to see how large the image will be on paper), this setting is only accurate on 72 pixels-per-inch monitorsin other words, on those old 13-inch Apple monitors and hardly anything else. We just ignore it.

Tip: Don't Select the Zoom Tool

We never select the Zoom tool from the Tool palette. You can always get the Zoom tool temporarily by holding down Command-spacebar (to zoom in) or Command-Option-spacebar (to zoom out). Each click reduces from actual size to two-thirds (66.7 percent), to one-half (50 percent), to one-third (33.3 percent), and so on when zooming out, and magnifies in 100-percent increments when zooming in. (Actually, it jumps from 800 to 1200 percent, and from 1200 to 1600 percent, which is the maximum magnification available.)

You can also drag around an area with the Zoom tool. The pixels within the marquee are magnified to whatever percentage best fills the screen.

Tip: Zoom with Keystrokes

If you just want to change the overall magnification of an image, press Command-plus (+) or Command-minus (-) to zoom in or out. We find this especially handy because it resizes the window at the same time if necessary. But if any palettes are open, this keystroke won't increase the document window beyond the edges of the palettes unless you click the Ignore Palettes checkbox in the Options bar while the Zoom tool is selected. Note that adding the Option key to this mix tells Photoshop to zoom in or out without changing the size of the window. For some reason, it's just the opposite in Windows: The Ctrl key zooms without resizing, and holding down Ctrl and Alt zooms and resizes.

Tip: Zoom with the Scroll Wheel

If your mouse has a scroll wheel, you can use it to scroll or zoom. By default, it's set to scroll, and pressing Option while turning the wheel makes it zoom instead. To reverse this behavior, check Zoom with Scroll Wheel in General Preferences.

Tip: Get to 100-Percent View Quickly

You can jump to 100-percent view quickly by double-clicking on the Zoom tool in the Tool palette. This is just the same as clicking the Actual Pixels button in the Options bar or choosing Actual Pixels from the View menu. Faster still, press Command-Option-0 (zero).

Tip: Fit Window in Screen

Double-clicking on the Hand tool, on the other hand (no pun left unturned), is the same as clicking Fit on Screen in the Options bar when the Zoom tool or Hand tool is selected, or pressing Command-0 (zero)it makes the image and the document window as large as it can, without going out of the screen's boundaries.

Tip: Zoom Factor

At the bottom-left corner of the window, Photoshop displays the current magnification percentage. This isn't only a display: You can change it to whatever percentage you'd like (double-click to select the whole field). Type the zoom percentage you want, then press Return or Enter when you're done. If you're not sure exactly what percentage you want, note that you can press Shift-Return instead of Return and the field remains selected after Photoshop zooms in or out, letting you enter a different value (see Figure 2-3).

Moving

If you're like most Photoshop users, you find yourself moving around the image a lot. Do a little here . . . do a little there . . . and so on. But when you're doing this kind of navigation, you should rarely use the scroll bars. There are much better ways.

Tip: Use the Grabber Hand

The best way to make a small move around your image is with the Grabber Hand. Don't choose it from the Tool palette. Instead, hold down the spacebar to get the Grabber Hand. Then just click-and-drag to where you want to go.

Grab Every Image

Wouldn't it be cool if you could use the Grabber Hand on more than one open image window at the same time? No problem: Just hold down the Shift key with the Grabber Hand tool (or press Shift-spacebar with any other tool). This works when zooming in and out, too: Just add the Shift key and your magnification change gets applied to all open images.

Info Palette," later in this chapter.) If your mom has a feathered halo around her, you may not be able to get this to work if you click on the feathered part.

Navigator Palette

The Navigator palette acts as command central for all scrolling and zooming (see Figure 2-4). We rarely use this palette because we find that it's usually either too precise or not precise enough, and it takes too much mousing around. Of course, this is largely a personal bias on our part; if you find it useful, more power to you.

Most of the palette is occupied by a thumbnail of the image, with a red frame indicating the contents of the active window. (If your image has a lot of red in it, you might want to change the frame color by choosing Palette Options from the palette's flyout menu). Dragging the outline pans the contents of the active window. Command-dragging lets you define a new outline, thereby changing the zoom percentage.

The percentage field at the lower left of the palette works exactly like the one at the lower left of the image window. Clicking the zoom-in and zoom-out buttons has the same effect as pressing Command-plus and Command-minus. David's favorite feature in this palette is the magnification slider, which lets him change the zoom level dynamically. It's not a particularly useful feature, but it's mighty fun.