The Perspective option controls whether a 3D view displays as perspective instead of orthographic.
Video: Create a Perspective View
Video: Work with Uncropped Perspective Views
To create a perspective view
Revit LT creates a perspective 3D view and assigns a name to the view: 3D View1, 3D View2, and so on. To rename the view, in the Project Browser right-click it, and select Rename.
You can use a section box to limit the viewable portion of a 3D view.