By default, images are displayed at 100% magnification; however, you can zoom in to get a closer look at image detail or zoom out to view a larger portion of the image. You can also specify the magnification level at which images open.
In the toolbox, click the Zoom tool .
Do the following
Click the image where you want to magnify it.
Zoom in to a specific area
Drag across the area you want to magnify.
Right-click in the image window.
Switch between the current and previous zoom levels
Click the Zoom to previous button on the property bar.
Zoom in or out by a preset level
Choose a magnification level from the Zoom list box on the property bar.
You can also zoom in to or out from the image using a mouse wheel.
To set the magnification level at which images are opened
In the Workspace list of categories, click General.
Choose a magnification level from the Opening zoom list box.
The magnification level that you choose is used the next time you open an image.