Breathe new life into your Cooke Optics S4 12mm lens. This Xpander, when mounted on the rear of the Cooke 12mm lens, converts the image circle to cover Open Gate in the Alexa 35 and other Super-35 cinema cameras.  The original lens design only covered the Academy Aperture, limiting the use with modern digital cinema cameras. This Xpander, designed with the highest quality optics, is easily installed on the rear of the lens by removing 6 screws, replacing the factory PL mount.