Port windows are a specialized and often overlooked part of digital projection in both old and new theaters. Reel-to-reel film projectors did not require advanced optical technology for the port window. With the introduction of digital projectors, that became a necessity. The leading studios and major chains throughout the world have chosen Opticlear as their standard. Optical Coatings has supplied over ¾ of the world's cinemas. Our pricing, availability, customization & service all contribute to a high rate of customer satisfaction.