Colour Light Output
- an easy way to evaluate projector colour output
What is Colour Light Output?
Colour Light Output (CLO) is a specifi cation that
provides critical information on a projector’s ability to
deliver colour. Developed by colour scientists using
the same approach as White Light Output (Brightness)
measurement, Colour Light Output provides the buyer
with additional key information about colour.
Does Brightness measure colour?
No. Current product specifi cations such as Brightness
(or White Light Output), Contrast Ratio and Resolution
give no information regarding a projector’s ability to
reproduce colour. The existing Brightness specifi cation
only measures the total amount of White Light projected.
It does not measure colour – in fact, many manufacturers
artifi cially boost brightness by adding white light, which
dilutes the projector’s colour brightness.
Why is Colour Light Output important?
Colour Light Output is critically important because it
measures the brightness of Red, Green and Blue. Red,
Green and Blue create white when combined in the right
proportions. They also comprise the input signal that
tells your projector how to reproduce colour images.
Beautifully balanced colour is possible when bright Red,
Green and Blue combine to produce the brightness equal
to White. Colour Light Output provides users with an
additional way to evaluate a projector and make more
discerning buying decisions.
Is Colour Light Output the same in all
projectors?
No. There are vast differences in the Colour Light Output
of projectors on the market today. Look at the images
below from two competing projectors
How is Colour Light Output measured?
Image #2*
Image #2*
Brightness (or White Light
Output)
measures the
total amount of white light
projected in lumens on a
nine point grid. It does not
measure colour.
Colour Light Output
uses
3 sets of a nine-point grid to
measure the primary colours
- red, green and blue, using
the same approach used to
measure White Light Output
in lumens.
How should Colour Light Output be used?
Colour Light Output should be used with White Light
Output to provide insight into a projector’s overall picture
quality. Two things to remember:
3LCD Projector
Brand X
Image #1*
Image #1*
When selecting a projector, ask for
the Colour Light Output measurement.
1. Select High Colour Light Output.
2. Make sure the Colour Light Output
equals the White Light Output.
Colour Light Output specifi cation
describes the difference in colour between
these two projectors.
Brand X
Low CLO
White Light Output
Colour Light Output
800 Lumens
=
/
2200 Lumens
=
2200 Lumens
2200 Lumens
White Light Output
Colour Light Output
3LCD
Projector
High CLO
* Actual photographs of images produced by 2 competing
projectors run in default mode. Price, Resolution and Brightness
(White Light Output) are the same for both projectors.
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Red
Red
Green
Green
Blue
Blue
Red
Blue
Green
