A target for use in white balancing video cameras and, in particular, video cameras suitable for endoscopic use. The target is molded from an elastomeric material having the ability to diffuse a substantial portion of light incident upon the target from a video camera. A user may use the target to white...http://www.google.es/patents/US5365267?utm_source=gb-gplus-sharePatente US5365267 - White balance target
