Photoshop.CS.Bible [Electronic resources] نسخه متنی

Navigating in Photoshop

All graphics and desktop publishing programs provide a variety of navigational tools and functions that enable you to scoot around the screen, visit the heartland and nether regions, examine the fine details, and take in the big picture. And Photoshop is no exception. In fact, Photoshop's navigation tools would make Magellan drool (were he inclined to edit an image or two).

The view size

You can change the view size — the size at which an image appears on screen — so you can either see more of an image or concentrate on individual pixels. Each change in view size is expressed as a zoom ratio, which is the ratio between screen pixels and image pixels. Photoshop displays the zoom ratio as a percentage value in the title bar as well as in the magnification box. The 100-percent zoom ratio shows one image pixel for each screen pixel (and is therefore equivalent to the old 1:1 zoom ratio in Photoshop 3 and earlier). A 200-percent zoom ratio doubles the size of the image pixels on screen, and so on.

Actual pixels

Photoshop calls the 100-percent zoom ratio the actual-pixels view. This is the most accurate view size because you can see the image as it really is. Reduced view sizes drop pixels; magnified view sizes stretch pixels. Only the actual-pixels view displays each pixel without a trace of screen distortion.

You can switch to this most accurate of view sizes at any time using one of the following techniques:

Choose View Actual Pixels.

Press Ctrl+Alt+0 (z -Option-0 on the Mac). That's the number 0, not the letter O.

Double-click the zoom tool icon in the toolbox.

Click the Actual Pixels button, which appears in the Options bar when the zoom tool is selected.

Fit on screen

When you first open an image, Photoshop displays it at the largest zoom ratio (up to 100 percent) that permits the entire image to fit on screen. Assuming you don't change the size of the image, you can return to this "fit-on-screen" view size in one of the following ways:

Choose View Fit on Screen.

Press Ctrl+0 (Win) or z -0 (Mac).

Double-click the hand tool icon in the toolbox.

Select the zoom tool and then click the Fit on Screen button in the Options bar.

Strangely, any of these techniques may magnify the image beyond the 100-percent view size. When working on a very small image, for example, Photoshop enlarges the image to fill the screen, even if this means maxing out the zoom to 1,600 percent. Personally, I prefer to use the fit-on-screen view only when working on very large images.

Well, actually, I almost never use the fit-on-screen view because it's too arbitrary. Photoshop does the best job of previewing an image when you can see all pixels ? that is, at 100-percent view size. Short of that, you want the screen pixels to divide evenly into the image pixels. This means view sizes such as 50 percent or 25 percent, but not 75 percent or 66.7 percent. And you never know what the zoom ratio is going to be with the fit-on-screen view.

Print size

You can switch to yet another predefined view size by choosing View Print Size. This command theoretically displays the image on screen at the size it will print. (You set the print size using Image Image Size, as I explain in Chapter 3.) When the zoom tool is active, you also can click the Print Size button in the Options bar to turn on the print-size view.

In practice, "print-size" view isn't particularly reliable. Photoshop assumes that your monitor displays exactly 72 pixels per inch, even on the PC, where the accepted screen resolution is 96 pixels per inch. But it's all complete nonsense, whatever the assumption. Monitor resolutions vary all over the map. And high-end monitors let you change screen resolutions without Photoshop even noticing.

The long and the short of it is this: Don't expect to hold up your printed image and have it exactly match the print-size view on screen. It's a rough approximation, designed to show you how the image will look when imported into InDesign, QuarkXPress, PageMaker, or some other publishing program — nothing more.

The zoom tool

Obviously, the aforementioned zoom ratios aren't the only ones available to you. You can zoom in as close as 1,600 percent and zoom out to 0.2 percent.

The most straightforward way to zoom in and out of your image is to use the zoom tool:

Click in the image window with the zoom tool to magnify the image in preset increments — from 33.33 percent to 50 to 66.67 to 100 to 200 and so on. Photoshop centers the zoomed view at the point where you clicked (or comes as close as possible).

Alt-click (Win) or Option-click (Mac) with the zoom tool to reduce the image incrementally — 200 to 100 to 66.67 to 50 to 33.33 and so on. Again, Photoshop tries to center the new view on the click point.

TipDrag with the zoom tool to draw a rectangular marquee around the portion of the image you want to magnify. Photoshop magnifies the image so the marqueed area fits just inside the image window. (If the horizontal and vertical proportions of the marquee do not match those of your screen — for example, if you draw a tall, thin marquee or a really short, wide one — Photoshop favors the smaller of the two possible zoom ratios to avoid hiding any detail inside the marquee.)

If you want Photoshop to resize the window when you click with the zoom tool, select the Resize Windows to Fit check box in the Options bar. The check box appears only when the zoom tool is the active tool.

Turn off the Ignore Palettes check box in the Options bar if you want Photoshop to stop resizing the window when the window bumps up against a palette anchored against the side of the program window. Turn the option on to resize the window regardless of the palettes. The palettes then float over the resized window.

PhoteshopIf you have multiple image windows open, you can control the zoom ratio on all of them at the same time. Simply Shift-click with the zoom tool in any image window. Alternatively, you can eliminate the need for the Shift key by turning on the Zoom All Windows check box in the Options bar.

The zoom commands

You can also zoom in and out using the following commands and keyboard shortcuts:

Choose View Zoom In or press Ctrl+plus (+) (z -plus on the Mac) to zoom in. This command works exactly like clicking with the zoom tool except you can't specify the center of the new view size. Photoshop merely centers the zoom in keeping with the previous view size.

Choose View Zoom Out or press Ctrl+minus (?) (z -minus on the Mac) to zoom out.

If Photoshop is unresponsive to these or any other keyboard shortcuts, it's probably because the image window has somehow become inactive. (It can happen in Windows if you so much as click the taskbar.) Just click the image window's title bar and try again.

The magnification box

Another way to zoom in and out without changing the window size is to enter a value into the magnification box, located in the lower-left corner of the Photoshop window (or image window on the Mac). Select the magnification value, enter a new one, and press Enter or Return. Photoshop zooms the view without zooming the window. (Neither the Resize Windows to Fit check box in the Options bar nor the Zoom Resizes Windows option in the Preferences dialog box affect the magnification box.)

In Figure 2-13, I started with a specially sized window at 25 percent. I then entered two different zoom ratios in the magnification box — 57.8 percent and 18.9 percent — alternately enlarging and reducing the image in the confines of a static window.

Figure 2-13: To zoom an image without changing the window size, enter a zoom ratio in the magnification box and press Enter or Return. Alternatively, deselect the Resize Windows to Fit check box in the Options bar when working with the zoom tool.

You might like to know more about the magnification box:

TipYou can enter values in the magnification box as percentages, ratios, or "times" values. To switch to a zoom value of 250 percent, for example, you can enter 250%, 5:2, or 2.5x.

You can specify a zoom value in increments as small as 0.01 percent. So if a zoom value of 250.01 doesn't quite suit your fancy, you can try 250.02. I seriously doubt you'll need this kind of precision, but isn't it great to know that it's there?

Creating a reference window

In ancient days, paint programs provided a cropped view of your image at the actual-pixels view size to serve as a reference when you worked in a magnified view. Photoshop CS does not, because it's so doggone modern, but you can easily create a second view of your image by choosing Window Arrange New Window, as in Figure 2-14. Use one window to maintain a 100-percent view of your image while you zoom and edit inside the other window. Both windows track the changes to the image.

Figure 2-14: You can create multiple windows to track the changes made to a single image by choosing the New Window command from the Arrange submenu of the Window menu.

Scrolling in the window

In the standard window mode, you have access to scroll bars, as you do in just about every other major application. But as you become more proficient with Photoshop, you'll use the scroll bars less and less. One way to bypass the scroll bars is to use the keyboard equivalents listed in Table 2-1. If you're using a Mac that lacks the Page Up and Page Down keys — such as an older model PowerBook — try out the Control key equivalents in the third column. These may also come in handy when the Page Up and Page Down keys don't always behave properly, as on new PowerBook and iBook keyboards that require you to press a separate Fn key.

I've heard tales of artists who use the Page Up and Page Down shortcuts to comb through very large images at 100-percent view size. This way, they can make sure all their pixels are in order before going to print.

Personally, however, I don't use the Page key tricks very often. I'm the kind of merry lad who prefers to scroll by hand. Armed with the grabber hand — as old-timers call it — you can yank an image and pull it in any direction you choose. A good grabber hand is better than a scroll bar any day.

Zooming and scrolling to match

Match Zoom: Choose this command to change the zoom ratio of all open images to match the zoom ratio of the active image window.

Match Location: This command is just the ticket when you want to scroll all open images to the same location as the active image window.

Match Zoom and Location: Choose this command to change the zoom ratio and location of all open images to match the active image window. Like you needed me to tell you that.

The Navigator palette

I saved the best for last. Shown in Figure 2-15, the Navigator palette is the best thing to happen to zooming and scrolling since Photoshop was introduced. If you routinely work on large images that extend beyond the confines of your relatively tiny screen, you'll want to get up and running with this palette as soon as possible.

Figure 2-15: The Navigator palette is the best thing to happen to zooming and scrolling since Photoshop 1.0.

If the Navigator palette isn't visible, choose Window Navigator. You can then use the palette options as follows:

View box: Drag the view box inside the image thumbnail to reveal some hidden portion of the photograph. Photoshop dynamically tracks your adjustments in the image window. Isn't it great?

You can also Shift-drag to constrain dragging the view box to only horizontal or vertical movement.

Box color: You can change the color of the view box by choosing the Palette Options command from the palette menu. My favorite setting is yellow, but it ultimately depends on the colors in your image. Ideally, you want something that stands out. To lift a color from the image itself, move the cursor outside the dialog box and click in the image window with the eyedropper.

Magnification box: This value works like the one in the lower-left corner of the Photoshop window (or image window on the Mac.) Just enter a new zoom ratio and press Enter or Return.

Zoom out: Click the zoom out button to reduce the view size in the same predefined increments as the zoom tool. This button doesn't alter the size of the image window, regardless of any window resizing options you set for the other zoom controls.

Zoom slider: Give the slider triangle a yank and see where it takes you. Drag to the left to zoom out; drag right to zoom in. Again, Photoshop dynamically tracks your changes in the image window. Dang, it's nice to zoom on-the-fly.

Zoom in: Click the big mountains to incrementally magnify the view of the image without altering the window size.

Size box: If you have a large monitor, you don't have to settle for that teeny thumbnail of the image. Drag the size box to enlarge both palette and thumbnail to a more reasonable size.