Zeiss Otus 85mm f/1.4 Apo Planar T ZF Manual Focus Lens for Nikon F Mount Prime portrait-length lens designed for Nikon F-mount FX-format DSLRs and 35mm film cameras. It is also compatible with DX-format DSLRs, where it will provide a 35mm-equivalent focal length of 127.5mm. Fast f/1.4 maximum aperture benefits working in difficult lighting conditions and also enables extensive control over focus placement for shallow depth of field and selective focus applications. One aspherical element and six elements made from anomalous partial dispersion glass help to suppress chromatic aberrations for greater clarity and color accuracy around subject edges, regardless of the aperture setting in use. Based on the Planar optical concept, this apochromatic lens virtually eliminates both chromatic and spherical aberrations in order to reduce color fringing and color artifacts in front of and behind the plane of focus. A floating element design places variable air gaps between select lens groups to realize consistent performance throughout the focusing range, from 2.6' to infinity.