Tonal Response Curve - NEC SpectraView Reference 241 User Manual

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4.5.2 Tonal response curve

Shades of gray from black to white will be reproduced in a specific way,
depending on the individual monitor. CRTs and LCDs are very differ-
ent in their native characteristics. In order to normalize the response
character monitor calibration corrects the tonal response curves to a
defined function.
L* (recommended)
Theoretically, the ideal color system for cross media publishing is L*a*b*.
It equals the characteristics of human color perception. So, it is logical
to combine the advantages of the L*a*b* with the representation of tone
values on a monitor.
The L* method calibrates your monitor in such a way that gray scales
appear visually equidistant. If you increase the R, G and B signals by
the factor 2, the displayed color will be doubled in brightness. This way
the RGB monitor space is optimally adapted to the human visual sensa-
tion.
Since ICC profiles are based on L*a*b* as well, the conversion losses
are minimized when converting color to the monitor gamut. If you
calibrate your monitor to L*, your RGB working space should have
an L* tonal response curve also. You can download such a working
space from www.lstarrgb.com or make your own with basICCoolTool
SpaceLab from the basICColor GmbH.
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