Fisheye lens series drr danubia lens mount nikon f lens speed 35 focal length 8 mm suitable for sensor type aps c construction prime lens area of use landscape photography indoor photography close up photography focus manual focus internal focus closest focusing distance 30 cm lens types aspherical ed lens construction groupselements 710 minimum aperture 22 max aperture 35 lens switch afmf coating multicoating mc length 980 mm weig