This circular fisheye lens produces circular images with an angle of view of 180-degrees when attached to a full-frame digital or 35mm film SLR camera. It has a fast maximum aperture of f/3.5 and a minimum focusing distance of 13.5cm. Sigma's super multi-layer coating and Special Low Dispersion (SLD) glass provide excellent image quality
This lens is perfectly suited for low light conditions indoors or at dusk. Special Low Dispersion (SLD) glass offers effective compensation of color aberration. Sigma's super multi-layer lens coating reduces flare and ghosting, a common problem with digital cameras and also creates an optimum color balance. 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.