LIGHT BEAM CONTROLS

The width of the light beam is controlled by the knobs on the side of the lamp arm nearest the bottom.

The height of the beam is controlled by the knob near the top of the illumination tower.  The height of the beam is shown in the small window 
above the height control knob.  (On 
some models there is a lever below 
the filter lever which adjusts the 
beam height.)  The lever between 
the height control and window is used 
to put neutral density filters,  cobalt 
and green filters in the light beam.

The top portion of the light tower 
rotates the light beam.  The post that the height adjustment knob is on can be grasped to rotate this part of the tower.  The amount of rotation is noted on the scale at the position of the metal rod below beam height control.  This is useful, for example, in measuring the rotation of toric contact lenses.