It gives an immense field of view - 180 degrees, with a 12mm (35mm equivalent) field of view.
The optical construction of the lens is 11 elements in 8 optical groups including 2 aspherical and 3 ed elements for optimum optical performance. The aperture consists of six diaphragm blades with apertures available from f2.8 to f22. The samyang 8mm fisheye features the latest generation multilayer anti-reflection ultra multi-coating (Umc) to minimise flare and ghosting. The integrated lens hood also helps to reduce flare from behind the lens.
Due to the very large depth of field produced by such a small focal length lens, focus can be easily achieved by simply setting the approximate distance on the lens scale. As with all manual focus lenses for critical or in very close focus situations you can use live-view to fine-tune the focus manually. The samyang 8mm f2.8 fish-eye lens is also capable of producing panoramas and 360 virtual tours, including full 360 degree images.
Fisheye lenses are also popular for special Effects use where distortion, exaggerated perspective, or extreme depth of field are desired.