C-700 Brochure

SEKONIC

Light Balancing  lters are placed in front of light sources to adjust their color temperature. CTO (Color Temperature

Orange)  lters will lower cooler (bluish light) color temperature light sources such as  ash, HMI’s,  orescent or LED lights

and provide warmer tones. CTB (Color Temperature Blue)  lters will raise warmer (yellowish light) color temperatures

light sources such as tungsten or natural lights providing cooler tones. Color correcting  lters are, Plus/Minus green

 lters that compensate for green tones that are commonly found in  uorescent light sources.

The image on the left was photographed under  uorescence lighting with the camera set to daylight conditions. The

image on the right was photographed after the  uorescence lights were light balanced with gels to match the camera

settings.

CRI (Color Rendering Index) is a quantitative

measure revealing the ability of a light source to

represent the colors of various objects faithfully in

comparison with an ideal or natural light source.

The Color Rendering Index (CRI) is a scale from

0 to 100, which describes how a light source

makes the color of an object appear to the human

eye and how well subtle variations in colors and

shades are revealed. The higher the CRI, the better

the color rendering ability. A Black Body Radiator

(i.e.: a  lament from a light bulb) is considered the

“reference” light source and they produce a CRI value of 100. CRI values can be evaluated from R1 through R8 (color

rendering index) and R9 through R15 (special color rendering index). Each R value represents a color for speci c color

rendering performance for the measured light source. Ra is commonly used because it represents an average color

rendering performance of a light source from R1 through R8. It is important to measure various di erent light sources

for their CRI values before using them for a shoot or production.

Color correcting and Light Balancing ﬁ lters

What is CRI and why is it important?

Color Meters vs. Spectrometers

Traditional color meters for photo/video and cine applications were designed

to match  lm sensitivity by using three photo sensors with R, G, B color  lters.

Since more images are captured with digital cameras, professionals have

noticed that traditional color meters may not match their digital cameras as

they expect because the digital sensor is designed to match the sensitivity

of human eyes. In addition, it is di cult for three photo sensors with color

 lters to read the spikes that some light sources can produce such as LED or

Fluorescents. Instead, the Spectrometers like the C-700 series can analyze the

light from 380nm to 780nm and provide a more precise measurement, which

matches the human eyes sensitivity standardized by the CIE (Commission

Internationale de I’Eclairage). Through its advanced measuring system, it

provides full spectral data of the light source along with CRI information as well

as intensity of light (illumination). Industrial spectrometers do not show LB or

CC  lters correction, however the C-700 series does provide the necessary

information required to capture images in their true colors.

SECTION

EDUCATIONAL

What is CRI and why is it important? What is CRI and why is it important?