When editing a document in Photoshop, it is often necessary to change your view of the document for ease while editing. Using the zoom tool allows you to work closely on a smaller area by enlarging the selected area, or zoom out to see the document in its entirety. There are three primary ways to use the zoom function in Photoshop; they are the zoom icon, the navigator icon, and the navigator panel.
Zoom Icon: Using the tool bar
Click on the zoom icon from the tool bar on the right hand-side. With the magnifying glass, click onto the area in which you wish to magnify.
The magnifying glass can control the "zoom in" (magnify) function, but you can also "zoom out" (reduce) from the image by changing the setting in the upper left hand corner:
Command Zoom: Using a keyboard shortcut
To zoom in quickly on the center of the image, press the Command key and the plus key (+) simultaneously. To zoom out, press Command and the minus key (-). After zooming, you may scroll vertically and/or horizontally to refine the zoom's location on the document.
Navigator Zoom: Fine-tune control
The navigator zoom provides a more detailed visual representation of the zoom location, giving the user more precise control over zoom level and location on the document.
The Navigator Panel can be found on the right side of the screen. Click the Navigator tab to activate the Navigator display. The Navigator renders a preview of the document. The red box in the display represents what you will see given the current zoom level. Drag the red box to the area you wish to focus on. On the bottom edge of the navigator panel, there is a blue slider, with mountain-like buttons on each side.
You may click and drag this slider to increase or decrease the zoom level. Left is to zoom out, right is to zoom in. Alternately, you can click the buttons on either side to increase or decrease zoom level. Again, the left button will zoom out, the right will zoom in. If you want to be precise, you can also type in a percent value in the lower left corner of the display and press enter. The zoom level will adjust accordingly.