OM System BCL-0980 9mm F8.0 Fisheye Body Cap Lens

The BCL-0980 is a body cap with a lens in it. 22.5mm deep, 71g, fixed at F8.0, with a sliding lever that moves between the closed position, normal focus and a close-focus setting at 0.2m. There is no autofocus and no aperture ring, which is the point: it is a lens you leave on the camera as a cap and use when a 180 degree view suits the picture.

At F8.0 on Micro Four Thirds most of the frame is in focus anyway, so the lever is more of a hyperfocal switch than a focusing control. The multi-coated optics hold up better against flare than the price suggests, and the 43mm filter thread takes a protector.