The insert can be zoomed in to view details of the model.

Key combination Mouse movement/button Zoom
Mouse scroll wheel before Zoom in
back Zoom out
< button < Zoom out
Shift + < key > Zoom in

Note:  When zooming with the mouse wheel, the perspective changes as the area under the mouse cursor is zoomed.

Attention:        If zooming in with the mouse scroll wheel does not work, make sure that the window is activated. Click once on the workspace with the left mouse button. If the window is activated, make sure that the 1:1 view is not activated.