This custom 'hyperfisheye' lens can see behind itself

This custom 'hyperfisheye' lens can see behind itself

If you're doing ordinary photography and videography, there's rarely any need to go beyond extreme wide-angle lenses — but why be ordinary? This absurd custom fisheye lens has a 270-degree field of view, meaning it can see behind the camera it's mounted on — or rather the camera mounted on it. It's certainly a bit of fun from Lens Rentals, the outfit that put it together, but it's definitely real and might even be useful.