From the Standard Views dropdown 
, you can also select a display orientation of Front, Back, Left, Right, Top, Bottom or Isometric.
Note
Selecting a Standard View when the Active Camera Type is selected will also update the Real-Time View.
Choose the Perspective or Orthographic Camera Type to unlink the real-time viewing mode from the Geometry View allowing you to control the two views independently of each other. However, you will still see the real-time movement and postion of the active camera.