Apple Macintosh Performa 577 - Manual (Page 142)

Adjustments Light Meter Setup - 21
Light Meter Setup
This topic covers setup for
three light meter models:
R77, L-248, and 246.
Model R77 (Apple part
number 076-0310) is the
newest model available.
Model R77
The R77 light meter is
capable of reading luminance
from 10 to 1,000
footcandles (fc).
Before you begin, remove
the 10X multiplier plate