Many windows in PS can be resized and their content magnified. The primary PS windows, such as the Setup, Image, Retinal Diagram and so on, consist of a toolbar across the top, a content region, and one or more additional control regions. The content region is always the largest rectangular portion of the window in which, for example, a 3D rendering or diagram or CT image is displayed and manipulated.
The current size and magnification factor of the content region of a window are displayed in a gray button at the lower left corner. The buttons to the right of the placard zoom out (minify), zoom in (magnify) and return to the default home view.
Clicking in the gray button opens the Window Magification & Content Size Dialog Sheet wherein you can enter specific values for magification and content size. The buttons along the right side of the dialog quickly create standardized content sizes that are useful for creating figures and movies for publication, lectures, and this user guide.
Note: any window, including content and controls, can be captured as a .png file using the MacOSX screen capture keyboard commands. For example, press command-shift-4, place the cursor over the window to capture, hit the spacebar on the keyboard to select the window, and click the cursor. That's how all the figures in this user guide were captured.