The problem of early detection of sub surface Lap Joint corrosion in the fuselage section of aircraft is critical to the continued air worthiness of aging aircraft. The large area of lap joint to be inspected requires a high speed system of measurement. D Sight is an enhanced visual technique that allows rapid inspection and early detection of lap joint corrosion. With the presence of inter-layer corrosion, a very distinctive surface budge or pillowing occurs between the lap joint rivets. D Sight imaging technology magnifies surface curvature changes to the exterior skin of the aircraft making them readily apparent. Extremely low levels of corrosion can be detected below the surface as the oxidized material distorts the lap joint and creates shape changes on the outermost skin. The D Sight sensitivity to local curvature change amplifies the effect dramatically and instantaneously. Stored D Sight images, compared with current images can readily determine a change in a specific area of an aircraft, while constantly updating maintenance records.