The Camera horizontal zoom value. Change this value to zoom in, or out of, a Scene.
A value of 0.5 would zoom the Camera out, so you can now see twice as much of the Scene as before. A value of 2 would zoom the Camera in, so every pixel now takes up 2 pixels when rendered.
Set to 1 to return to the default zoom level.
Be careful to never set this value to zero.