Canon EF 8-15mm f4 L USM Fisheye Zoom Lens

Despite being designed for full-frame cameras, the Canon EF 8-15mm f4L USM doesn't cover the full frame. But that's the point. At 8mm the lens creates breathtaking spherical images isolated in the center of a void. As you zoom in, so too does the image circle cover more of your sensor, and by 15mm the frame is fully covered. And it does this, while maintaining sharpness, thanks to ultra-low dispersion glass, and specialty coatings to protect the lens and prevent flares and ghosting.