Methods of determining the divergence angle between a primary image and a secondary image generated by a glazing are disclosed. In a first method, a glazing is illuminated with a light source and a primary and a secondary image of the light source, generated by the glazing, are captured using an image capture device. The distance between the primary and the secondary image is determined, and the divergence angle determined from this distance. In a second method, the primary and secondary images are viewed on a target marked with a scale indicating the divergence angle. The divergence angle is read from the scale and the positions the primary and secondary image. In this second method, the light source is located at the center of the target. In both methods, the light source comprises at least one light emitting diode. Preferably, the method is used to examine the edge region of a glazing.