Abstract: A lighting fixture with a controllable light block. The fixture includes a reflector and high intensity discharge lamp that requires a re-strike or warm-up period to come to full brightness or intensity. A cover member is mounted to the reflector and is moveable between an unblocked position and a blocked position. Movement of the cover member is immediate so that blockage of light from the fixture is immediately effectuated. The apparatus is configured so that cover member can be in the blocked position for indefinite periods of time even though the arc lamp continues to be operated at full power, without heat buildup which is detrimental to any part of the apparatus. The cover member also allows light control and special effects lighting options. Another aspect of the invention utilizes an aperture in the cover member that is alignable with the light source when the cover member is in the blocked position.