Sony NSR Series User'smanual page 64

Maximum Detectable Object Size
Enter a maximum size for the object to be detected.
Alternatively, configure the size by using the mouse to
drag the maximum detectable object size setting frame
(blue). You can change the size by dragging each of the
edges. The setting frame cannot be deleted.
G Apply
This saves the settings.
H Cancel
This cancels the changes to the settings.
64
Configuring Motion Detection Settings