Changing Arc Lamps



  1. Move collector lens away from bulb (knob on lamp housing) or remove lens entirely. Separate socket from lamp housing (retaining screw).
  2. Remove copper wire from post (thumb screw) then pull bulb upwards from socket (loosen lug nut at base; special wrench). Remove heat sink (silver cap on bulb; set screw).
  3. Reverse steps 1-2 to reinstall new bulb, being careful not to put strain or stress on bulb when tightening fittings. (For 50W HBO burners make sure flat sealed surface is facing to side.)
  4. To align arc, remove an objective, rotate empty space into viewing position and place a white card flat on stage, revealing real and mirror arc images. Focus images using collector lens and align (see diagram) using centering screws on lamp housing.
  5. Defocus images to evenly illuminate field; reinstall objective.




  • For greater stability, run for one hour before using.
  • Never switch high pressure burners on and off quickly.