In all modes, when the cursor is over the active photograph window, you can press and hold the CTRL key to enter the Temporary Zoom / Pan mode.
When the CTRL key is pressed, the cursor will change to show the two possible actions.
When the CTRL key is held, the left mouse button pressed and held, and the mouse dragged, a region box will draw on the photograph. When the left mouse button is released a Zoom-Area command will be executed. See the section above for Zoom Area.
When the CTRL key is held, the right mouse button pressed and held, and the mouse dragged, the photograph will pan just as if the pan mode was being used.
You can think of this CTRL temporary mode as a quick way to get into Zoom-Area or Pan mode without ever leaving the mode you are in.
Note: short-cuts that use the CTRL key are still accessible in photograph windows. For instance, to access Undo one would press Ctrl and Z. If the cursor is over a photo the cursor will change to show the Temporary Zoom / Pan mode but when Z is then pressed the Undo function will be carried out.
Also note that alternatively you can use the Shift key for this zoom function based on a setting in Preferences. See Preferences - Application Settings.