Set Viewport Camera
Display > Set Viewport Camera
 

Description:
   
    The Set Viewport Camera (Display > Set Viewport Camera) submenu allows you to choose the camera for the current viewport. All cameras besides the perspective camera are orthagonal.  For all cameras except the perspective camera and the free orthographic camera, view rotation is disabled.

    The different cameras you can choose from are: Free Perspective, Free Ortho ("ortho" meaning orthographic projection, as in objects further away from the camera won't be made smaller to adjust for perspective), Top Ortho, Left Ortho, Right Ortho, Front Ortho, Back Ortho, and Bottom Ortho.


Notes:

-When more than one viewport is onscreen at once, only the active viewport's camera is changed.

-There is only one of each type of camera. Multiple viewports with the same camera setting will not have independent position and rotation controls.

-Camera options can be edited in the Display Options (Options > Display Options...) dialog.

- You can set a background image to use as a modeling guide for top, bottom, front, back, left, and right orthographic cameras using the Set Viewport Image command.