Dolly
Moves the view forward or backward. This tool lets you set certain options more precisely than the View Panel or Autodesk® ViewCube®.
Access this tool from the View palette:
Dolly Viewing Options
Eye/View/Up
These sliders let you define a view by moving the camera. The Eye position, View point position, and Up vector end point determine the view. The nine fields that define these positions contain decimal numbers. They represent, from left to right, the X, Y, and Z Coordinates for each of the three camera parameters. To see the camera as you modify it, use WindowDisplay > Toggles > Cameras .
Zoom
The Zoom slider takes a decimal number that defines the extent of the field of view of the camera. Values must be positive in the range of 0.2 to 179.
Auto Dolly
If this option is checked (default), holding down a mouse button without dragging in an orthographic window dollies smoothly in (left mouse button), or out (middle or right mouse buttons).
If this option is unchecked, or if you drag the mouse immediately, a dolly box is drawn and the view dollies in (if you drag right) or out (if you drag left) in discreet increments.