wall surface with light the beam distribution pattern achieved with the lens 38 is able to provide highly uniform illumination of an extended region of a wall surface definition the term u201c wall surface u201d is used here to mean a surface that is adjacent to a fixture used for illuminating that surface and can be a wall a backdrop a cyc screen a scrim an element of stage or studio scenery or any similar surface to be illuminated by an adjacent lighting fixture except for the lens structure 34 the fixture 10 may be identical to a known par fixture such as the source four u2122 lighting fixtures sold by electronic theatre controls inc of middleton wis u s a such known fixtures may be provided with removable and replaceable lens structures of various types such as refracting lens for various fixed beam angles and adjustable beam angles however known par fixtures and lenses are not suited for wall wash or cyc applications for example fig2 is an illustration of a known par fixture 40 used to illuminate a wall surface 42 the fixture 40 is supported on a floor surface 44 perpendicular to the wall surface 42 and is positioned adjacent to the wall surface 42 typically about three to six feet from the wall surface 42 the light beam axis of the fixture 40 is inclined from vertical and toward the wall surface 42 at an angle of about seventy degrees the central axis of the light beam from the fixture 40 strikes the wall surface 42 at a point 46 about eight or nine feet above the floor surface 44 the illumination of the wall surface 42 is.