Sony 16mm f/2.8 Fisheye A-Mount Autofocus Lens

Manufacturer's Description: 

Once a scientific tool but now a favorite of creative photographers, 
fisheye lenses forgo the restraints of rectilinear perspective—the 
complex “correction” that is required to keep straight lines looking 
straight—to deliver expansive images that cover an extremely wide 
angle of view with curvilinear perspective. The SAL16F28 provides 
an extremely wide 180° angle of view on 35mm full-frame format 
cameras (110° on APS-C format cameras). In addition to eye-catching 
interpretations of reality, it offers extended depth of field so that you 
can capture huge vistas in which everything from 20 centimeters to 
infinity is sharp, even at maximum aperture. Since the bulging front 
element and wide angle of view prevent the use of external screw-in 
filters, four selectable internal filter settings are provided: normal, O56 
monochrome, B12 red reduction and A12 blue reduction.