As creative as a body cap can get; It appears to be a protective body cap for your micro four-thirds camera, but this body cap also doubles as a fisheye lens with an 35mm equivalent focal length of 18mm.
Is It a Body Cap or a Lens? It’s Both.
Olympus also introduces an intriguing new lens for its Micro Four Thirds line. The BCL-15mm f8.0 Body Cap Lens serves as a body cap when carrying the camera around without its interchangeable lens, and transforms to become a pan-focus snapshot lens to capture images. The lens is so thin – just 9mm thick – that it can easily be mistaken for a camera-mount body cap. With three glass lens elements in three groups, it can be used as a wide-angle lens equivalent with a single focal length of 30mm (35mm camera equivalent). In addition to daily use as a “pan-focus” lens featuring a wide angle, fixed f8 aperture and deep depth of field, it is compatible with manual focusing using a lever and capable of close-up shooting as close as 30 cm. A lens-protection barrier is provided so the lens can be mounted permanently on the camera and even put in a pocket together with the camera.