By pressing and holding down the Ctrl key while dragging one of the three yellow camera snap points (marked with arrows in Figure 1), you can easily change Camera height and/or Target height.
Changing Camera height and Target height can also be done in the Camera Settings found in the Render & Camera Settings dialog.
Figure 1 Pressing and holding down the Ctrl
key while dragging
the yellow snap points (pointed out with arrows) makes it easy
to adjust the camera height and target height.