Today’s B&H DealZone (one-day deal) features the Lensbaby 5.8mm f/3.5 Circular Fisheye Lens for Canon EF for only $159.95. Save $140 from the regular price of $300, this is the lowest price seen yet!
This lens is designed for crop-sensor cameras and will give a full circular field of view. (It will work on a full-frame camera, but will produce a smaller image.)