An apparatus and method for web inspection utilize simultaneous capturing of
reflected
and transmitted light images for real-time merging of same. The reflected light
and transmitted light image capturing systems are registered with each other in
terms of the down-web and cross-web field being imaged. To allow for the simultaneous
acquisition of reflected and transmitted light images, the imaged portion of the
web is an unsupported span, and the web is tensioned to prevent sagging. The reflected
light and transmitted light image capturing systems each include multiple cameras
registered with each other in terms of down-web and cross-web imaging field, and
the cameras for the transmitted light image capturing are aligned directly with
the light source, which outputs light that is incident on the web at an angle.