Next we explored various component arrangements to hone in on the most effective VXR configuration. Several promising concepts were constructed as foam core mock-ups for client review. The mockups illustrated the approximate volumetric requirements of the film path, light path, optical path, camera, drive mechanism, PC Boards, and power supply components. This process defined basic engineering requirements, and component costs, but left overall unit design open for thorough investigation. As with the VXR, the Sierra form factor contributes significantly to the appeal of the unit. Aesthetically the SIERRA bridges the gap between architectural element and high tech medical device. The low profile and angular end caps were designed to blend the unit into the wall, (the primary mounting configuration), while the organic contours of the front panel suggest where the film is loaded and how the materials flow through the scanning process. Wireform feed and exit trays are gently curved to mimic the film path, and to provide a softer less angular access point for user hands. The wireform parts are also less visually dense than solid plastic parts and reduce the overall visual mass of the unit.