Designed for its somewhat insane 24mm f/14 probe lens, Laowa released a focal reducer that concentrates the light coming through the lens into a smaller, brighter image circle suited for a sensor smaller than full frame.
This means that the f/14 lens becomes a maximum aperture of f/10 for a crop or M43 sensor.
The Laowa probe lens- probably the oddest looking lens to come out in recent memory – has proven very popular for its ability to get unique shots. The lens is about two feet long, with the half of the barrel furthest from the camera completely waterproof, allowing for the lens to be placed in water or out in the elements.
The end of the lens has LED lights capable of being powered via a USB battery; a feature particularly valuable for shooters exploiting its macro capabilities.
Originally designed for full frame sensors, one drawback for the lens has been its very narrow aperture.
The $250 focal reducer is available as an adapter from PL or EF mounts (the two mounts previously offered for the lens) to EF, R, L, X and M43 mounts.