A large aperture full-frame fisheye lens with 180° diagonal angle of view. This lens has the world largest aperture of f/2.8 in its class at the time. This lens is called "full-frame fisheye lens" to distinguish from circular fisheye lenses, which produce circular images that do not fill the entire frame. It will actually focus closer than the minimum focusing distance of 0.3m on the lens scale, enabling closest shooting distance of 0.2m at smaller aperture. As filters cannot be attached to the lens front, four filters, SKY, Y3, O and R are built-in.