A retrofit LED lighting system for replacement of existing metal halide lamp driven by magnetic ballast is provided. The obturator assembly including a housing, a penetrating tip disposed at a distal end, an elongated shield including a guard extending from a shaft are movable relative to the penetrating tip, and a latch mechanism disposed generally within the housing. The support arm can articulate relative to the base assembly from a home, normally horizontal position to a position angled with respect to the direction of travel in order to enhance assembly procedures. The sleeve includes at least one pusher bar. Sensors have applications in rotor speed detection, magnetic field detection, read heads, and MRAM, for example. A drive coupling is provided which couples the first drive for adjusting elevation of the surgical microscope to the second drive for adjusting the ophthalmic magnifier lens.