Note: Full circle can only be captured with 35mm format digital SLR and film SLR cameras. Also, auto-focus is not supported by D40, D60, D3000, D3100, D5100, and D5000 cameras.
This circular fisheye lens produces images with an angle of view of 180° when attached to a full-frame digital or 35mm film SLR camera. It has a maximum magnification of 4.6x. Sigma's super multi-layer lens coating reduces flare and ghosting, a common problem with digital cameras. This lens can be used for scientific applications such as the solid angle measurements of cloud distribution over the sky, the vegetation distribution of the rain forest canopy, and more due to the quantifiable angle/area relationship it produces.