Minolta IIIF - Page 28

Problem Light Sources
The Color Meter IF uses three sensors (one each for red, green, and blue) to measure the light
from the source and determine the filtration required. It will provide accurate results for a variety of
common light sources. However, problems may occur with light sources with sharp peaks (or line
spectra) in their spectral power distributions. Such light sources include sodium lamps, mercury lamps,
metal-halide lamps, and some fluorescent lamps, such as the three-narrow-band lamps.
If photographs will be taken under such light sources, it is recommended that test photographs
be taken and color bracketing be performed. If there is a difference between the displayed filter
value and the actual required filtration, this difference will generally be the same for all lamps of
this type, and can thus be stored in one of the memory channels for later use. Please remember,
however, that it may not be possible to accurately reproduce all colors under such light sources,
regardless of the filters used.
Spectral power distributions
ML
|
S
/
KH
8 nu
ee E E a 3
400
500
600
700
(nm)
400
500
600
700
(nm)
50
Metal-halide lamp Amnon narrow-band
uorescent lamp
26