We describe a new 4096 4096 pixel CCD mosaic camera (MOCAM) available at the prime focus of the Canada-France-Hawaii Telescope (CFHT). The camera is a mosaic of four 2048 2048 Loral frontside-illuminated CCDs with 15 m pixels, providing a eld of view of 140 140 at a scale of 000 :21 pixel . MOCAM is equipped with B, V, R and I lters and has demonstrated image quality of 000 :5{000 :6 FWHM over ...