16. Color calibration
Preparations
1. S etup the ambient light conditions as it should be during the play out of the movie. (e.g. only the stairs and em ergenc y exit
lighting is switched on).
Note: In an optimal setup less than 1% of light from an y other source than the light from the projector should illuminate the
screen.
2. Configure the desired aspect ratio: e.g. FL AT or SCO P E (use mos t comm on aspect ratio). Do this by activating the correct LENS
file.
3. P osition the spectrometer per pendicular to the screen and m easure in the center of the screen.
4. S ta rt up Comm unicator and follow the laser white point calibration wizar d.
After white point calibration proceed immediately with color gamut calibration.
16.3 Color gamut calibration
Color G amut
Color G am ut is the entire range of reproducible colors by a particular device such as a projector. The entire range of reproducible
colors are typically defined so that horizontal and vertical directions describe saturation an d luminance changes, respectively. When
a color is "out of gamut," it is not possible to reach that co lor by the device.
520
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380
x
y
0.9
0.8
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0.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
1
Image 16-1
Sample Chromaticity Diagram with Color Gamut of target device (1).
Why apply color correction?
During the pos t-production process of a film , a specific color space is applied. This color space is the Target Color G amut Data
(TCGD). All movie content oper ates under t
hat gamut. To ensure that in the cinema theater the film is pr ojected within the same
color space as intended by the film industry, the color space of the pr ojector has to be corrected accordingly.
What has to be done?
The c olor coordinates for the projected primary colors must be measured on the screen. The values can be different than those
originally inside the projector due to reflection on the screen or due to the influence of the glass between the projection booth and
the theatre and even the projected colors are different from setup to s etup.
These meas ured color coordinates are references for the projector and will be entered so that the projector knows how its colors
are projected on the screen. T his reference measurement (MCGD), together with the delivered gamut file (TCGD) of the film w ill
introduce a color correction so that the film will be projected with the desired color target.
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R5906753 DPXK BLP SERIES 20/11/2017
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