Menu "View" - "Magnifier"

Switches on/off the special window in which that part of the tree which is under the mouse cursor is shown in 1:1 scale.

The Magnifier's window lacks the usual borders and title bar, however you can move it and change its size using the mouse.

In the center the window has a kind of a "sight" - a red cross that shows the exact position of the mouse cursor. Using this "sight" it is possible to position the mouse in the necessary frame with greater ease while remaining in small scale mode.