Edit Bar Controls - Rotate About.
This tool allows you to zoom out of and in the 3D scene by clicking and dragging up and down.
Rotate About - you can Zoom In/Out about the origin, the scene, selected objects or the view centre.
Simply click and drag to zoom in/out. Right-mouse click and select Cancel 3D Camera Zoom to cancel the tool.
Related topics: Notes On 3D Tools.