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1 1 Appendix
1-1. Glossar
Color Temperature
Color Temperature refers to the chromaticity of a heated object (commonly refer to as a black
body) that will vary according to its temperature. The color temperature is measured in units of
Kelvin (K) and refers to the temperature of a heated object at a given color or chromaticity. The
higher the color temperature is, the bluer the light, and the larger the Kelvin value becomes.
The lower the color temperature is, the redder the light, and the smaller the Kelvin value
becomes. The color temperature of a heated object (black body radiator) is correlated to the
color temperature of light and it is strictly defined as a correlated color temperature. Any
teference to color temperature in this manual includes correlated color temperature.
Light
This refers to the electromagnetic wavelength ranging from 380nm to 780nm that can be
detected by the human eye.
Black Body
Theoretically, this is an object that absorbs all wavelengths and when heated, emits light
equivalent to the applied color temperature.
Black-body Radiation | This refers to the light emitted by a black body. The amount of energy released for each
wavelength changes with the applied color temperature, resulting in visible color variations.
Correlated color
3 sensors (R-G+B) matched to the spectral characteristics of the human eye (known as a color
temperature
matching function) are used, and using the measurement values of the 3 sensors to calculate
values known as chromaticity coordinates, the chromaticity diagram points are used to derive
the correlated color temperature (K) and the deviation (Auv). At this time, only the light source
that is at the same point as a black-body that is considered to be a base color temperature is
teferred to as the "color temperature".
K
Expressed in absolute Kelvin temperature, with units of "K". 0 (zero) K is equivalent to -273.15
°C or -459.67°F.
Visual color
Displayed by using 3 sensors (R-G-B) approximated to the spectral characteristics of the
temperature
human eye (known as a color matching function) and calculating based on the ratio of the 3
sensors.
Photographic color
Displayed by using 3 sensors (R-G-B) approximated to the spectral characteristic of films and
temperature
calculating based on the ratio of the 3 sensors.
MK-
Read as "per mega Kelvin", this unit is based on the International System of Units and
equivalent to the traditional unit of MIRED (mrd). It expresses the inverse of color temperature.
The inverse of color temperature is 1,000,000 divided by the color temperature.
1,000,000
color temperature
The inverse color temperature decreases as the color temperature increases.
Ex.) 10,000K = 100MK`1, 3200K = 312.5MK1
If a 100K change is applied to both 10,000K and to 3200K, the human eye perceives the
change applied to 3200K as larger. In other words, there is a difference in perception of the
same change in color temperature depending on the color temperature's numerical value.
When the inverse color temperature is used, the human eye perceives a given amount of
change as the same for any color temperature.
daMK°!
MK" divided by 10. Because the unit MK"! is extremely small compared to the amount of
change in color temperature the human eye can perceive, and because performing corrections
is difficult, for practical purposes the unit daMK"!
(deca per mega Kelvin) is used. This unit is
also used in conventional filters that change color temperature.
Inverse color temperature =
LB index
The difference of the reciprocal of the selected color temperature and the reciprocal of the
measured color temperature. It is expressed in units of MK-! (equivalent to MIRED) or daMK"1.
LB filter
Stands for "Light Balancing Filter', and refers to a filter used for correcting color temperature in
photography. A blue filter is used to raise the light source color temperature, while an amber
filter is used to lower it. The filter number used in compensation can be expressed in daMK,
or deca Mired (1/10 of Mired), or the Kodak's Wratten or Lee's filter number. By using the
custom settings in the C-500/C-500R, the display can be changed to show the type of the filter
being used.
CC index
Number that expresses the amount of difference between the G component (green range) of
the measured light source and the base black-body radiation of the color temperature. 1 CC
index is equivalent to 2.5 CC filter number.
CC filter number
Stands for "Color Compensating Filter", and refers to a filter used for correcting color in
photography. The 6 different types of this filter are yellow (Y), magenta (M), cyan (C), blue (B),
green (G), and red (R), but the C-500/C-500R only uses the magenta (M) and green (G) types.
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