This grant will be used to replace the red and blue channel cameras on the Double Imaging Spectrograph (DIS) of the 3.5 meter telescope at the Apache Point Observatory. The detectors in the present cameras are outdated, having high noise, 12 to 40 electrons per pixel versus approximately 5 electrons per pixel for the new detectors, cosmetic defects, and low quantum efficiency. The replacement devices will be larger, 1048 x 1320 pixels versus 512 x 512 for the present blue channel camera and 800 x 800 pixels for the red channel camera, and provide a smaller plate-scale for the telescope.