50 mounted on the spindle stationary pulley 50 is mounted on pulley support plate 70 carriage 18 39 is rotatably mounted on the spindle 58 and rotates on the spindle between the two stationary pulleys 40 and 50 the opposite side is substantially the same except that fluid transition member 64 is attached to support post 16 39 with connecting conduits attached at 68 which can be flexible hoses if desired stationary pulley 50 is mounted on a pulley support 72 and stationary pulley 40 is mounted on spindle 58 39 members 74 and 76 provide additional support for the spindle 58 39 the carriage 58 is mounted on the spindle 58 39 and fluid transition 64 so that it may rotate the lens system mounting is shown in fig5 which is a sectional view taken at 5 5 of fig3 the mounting of each frame or panel 20 and 22 is identical and comprises securing the panel 20 to the carriages 18 and 18 39 by spindles 60 and 60 39 pulleys 36 are rigidly secured to the end of the spindle 60 and 60 39 the lens systems 26 mounted on support plates 44 are rotatably mounted on the spindle 60 and 60 39 by bushings 80 and 80 39 on which are mounted pulley supports 82 and 82 39 to which pulleys for rotating the lens 54 are attached the pulley supports 80 and 82 39 are also securely welded or attached to the lens support arms 44 the bushings 80 and 80 39 permit the lens system.