The Zoom level can be controlled in several different ways:
View menu Zoom command – invokes Zoom dialog
View Menu Zoom In command – zooms in 2 X
View Menu Zoom Out command – zooms out 2 X
Right-click menu – zooms around mouse cursor position
Toolbar buttons, described below
Mouse wheel – zooms around mouse cursor position, roll up for zoom in, and down for zoom out (panning is also available by holding down SHIFT or CTRL)
The Zoom In command can be invoked by the Toolbar button or the PgUp key.
The Zoom Out command can be invoked by the Toolbar button or the PgDn key.
The toolbar zoom combo box can apply arbitrary zoom factors from 6.25% to 1600%. You can select a predefined zoom level, or type in your own value.
The Zoom dialog allows direct selection of several different zoom levels, as well as entering a Custom zoom level in the same manner as the toolbar combo box.
Note that the zoom level automatically "rounds" itself off to an even binary number.