The standard view used in Neurolucida is a top-down perspective along the X and Y axes. This is the view displayed in the Tracing window and in the Macro View window.
If you are working in 3D, the Orthogonal View is a useful supplement to the standard view as it enables you to view your tracing from the side, along the X,Z axes or the Y,Z axes .
To open the Orthogonal View window, click this icon in the toolbar
or click Tools>Depth Filter.