This autofocus fisheye lens is designed for use with digital SLR cameras equipped with APS-C size image sensors. The Nikon version produces a diagonal angle of view of 180° (154° for Sigma, 167° for Canon). The diagonal field of view of this fisheye lens produces striking images with exaggerated perspective & distortion. The minimum focusing distance of 13.5cm, & maximum magnification 1:3.3 allows subjects to be as close as 1.8cm from the lens’ front element. The close focusing capability together with a large depth of field allow close up photography that covers objects surrounding the photographic subject. The Integral hood blocks out extraneous light & the Super Multi-Layer Coating minimizes flare & ghosting, creating superior image quality. It is equipped with an inner focusing system that creates high definition & excellent image quality over the whole frame. The HSM (Hyper Sonic Motor)ensures fast & quiet autofocusing & allows full-time manual focus override by rotation of the focus ring. The fast f/2.8 maximum aperture produces a bright image in the viewfinder making this lens ideal for low light photography. This lens is ideal for photographers using computer stitching software which requires circular fisheye images to be input, resulting in stitched panoramas. Due to the quantifiable angle/area relationship it produces, this lens can be used for scientific applications such as solid angle measurements of cloud distribution over the sky, or vegetation distribution of the rain forest canopy. This lens is supplied with a gelatin filter holder at the rear, allowing the use of gelatin filters.