23
4-2. Setting Light Receiving System
4-2-1. Measuring with Incident Light Function (Lumisphere Extended /Retracted)
Use either extended or retracted (flat) lumisphere
to measure incident light. Point the lumisphere at
the camera (lens optical axis) from a position close
to the subject and then measure.
1. Extending Lumisphere
Rotate the Lumisphere retracting ring
2
to
align the mark with the extended symbol (
)
on the meter head.
2. Retracting Lumisphere
Rotate the Lumisphere retracting ring
2
to
align the mark with retracted symbol (
)on
the meter head.
Lumisphere alighining mark
Lumisphere
retracting ring
2
Lumisphere
retracting ring
2
Extended (
)
Retracted (
)
Lumisphere Extended
Lumisphere Retracted (flat)
Extended lumisphere is used to measure
illumination of people, buildings, and
other three dimensional subjects.
Retracted lumisphere is used to measure
illumination of flat subjects such as
manuscripts, paintings, difference of one or
more light sources for ratio lighting (See P46
for details) and illumination in Lux or Foot-
candle (See P28 for details).
•
Try to minimize the influence fo the person taking the light measurements. (Do not obstruct the light sources. There
will also be reflected light from the person’s clothing, so do not allow this reflected light to enter the light receptor.)
•
If the light meter is used with the Lumisphere retracting ring in a middle position, distributed light quality will change,
and suitable measurements cannot be made.
•
Do not push down the lumisphere with your hand.
•
Because it may affect the precision of the measurements, be careful not to damage or dirty the Lumisphere/Light
receptor. When Lumisphere becomes dirty, wipe it with a dry, soft cloth. Never use organic solvent such as thinner or
benzene.