The URSA Mini B4 Lens Mount lets you swap the built in PL mount on your URSA Mini with a B4 mount. The precision glass optics of the B4 lens mount are specifically designed to match URSA Mini’s sensor with your high definition B4 lenses. You also get built in spherical aberration correction so you can use your lenses wide open with no blooming effect. The built in lens control connector works with both PL and B4 lenses, so it can be used for HD with B4 lenses today and Ultra HD with PL lenses tomorrow! URSA Mini PL is the perfect camera to help broadcasters make the transition between HD and Ultra HD!