Zoom Tool

With the zoom tool, the image is taken to a higher or lower magnification. Select the zoom tool by clicking it's icon or pressing z on your keyboard. When the tool is selected, the cursor becomes a small magnifier with a plus sign in the center. The plus indicates that clicking on the image will bring you closer to the image. Hold the Alt/Option key on the keyboard and the plus changes to a minus to zoom out. 

To use the zoom tool just click on the area of the image that you want to enlarge or reduce. Photoshop places the pixels that you clicked on in the center of the screen. The zoom will be at a pre-set percentage each time you click. If you click and drag a selection marquee Photoshop will zoom and center to the selected area. Double clicking on the zoom tool icon in the Photoshop toolbar will zoom the document window to 100 percent.

The zoom toolbar you can choose to resize the windows to fit. The checkbox labled ignore palettes will allow the window to enlarge past the boundaries of any palettes that you have open. The toolbar also has the same three buttons that appear on the Hand toolbar. 

To use the zoom tool while using another tool without selecting it from the Photoshop toolbar, hold down Ctrl/Command + Spacebar to zoom in, and Alt/Option + Spacebar to zoom out. 

The View menu contains five zoom commands. All of the commands, except print size, have keyboard equivalents. The zoom in and out commands can be issued using Ctrl/Command and the (+) plus or (-) minus key. 

Ctrl + 0 (zero) causes the image to fit to the widest dimensions on the screen. Pressing Alt/Option + Ctrl/Command + 0 (zero) causes the image to be shown at actual size. 

Photoshop also has a small box in the lower-left portion of the viewing area. You can double click in this box and zoom to any percentage by typing it and pressing enter. 

Here are some other keyboard commands that you can use with a large image. 

The Page Up key moves the image just slightly less than a full screen up. 

Shift + Page Up moves the image up about one tenth of the screen. 

Ctrl/Command + Page Up moves the image to the right one full screen. 

Replace the Page Up key with the Page Down key to do the previous commands in the opposite direction. 

The Home key will take you to the top left corner of the image and the End key goes to the bottom right corner of the image. 

TIP: Pretty obvious what this tool does. It allows you to zoom into your image. Don’t be dumb, it doesn’t actually change the size of your image. Hold the [Alt] key to zoom out. Holding the [Shift] key will zoom all of the windows you have open at the same time. Double-click on the Zoom Tool in the palette to go back to 100% view.