Measuring the brightness (luminance) of light reflected from the subject is
useful when subjects cannot be approached, for measuring light sources
(neon signs, etc.), and measuring highly reflective surfaces or translucent
subjects (stained glass, etc.).
To take a reflected-light measurement, hold the meter in front of the camera
and point the metering lens toward the part of the subject you want to
measure. If the subject area is small, you may have to move the meter closer
to the subject to measure it properly