View the original size of a page or image: Choose View > Actual Size.
Zoom to a particular section of a PDF or image: Choose Tools > Rectangular Selection, select the section, then choose View > Zoom to Selection. To see the document at actual size again, choose View > Actual Size.
View a page at a specific percentage of its original size: Type a percentage in the Scale field in the toolbar.
If you don’t see the Scale field, choose View > Customise Toolbar, then drag the Scale field to the toolbar.
Magnify an area in a PDF or image: Choose Tools > Show Magnifier, then move the pointer over the area you want to magnify. To stop magnifying, choose Tools > Hide Magnifier or press the Esc key.