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<strong>Veritas</strong> <strong>et</strong> <strong>Visus</strong> <strong>Display</strong> <strong>Standard</strong> February 2009<br />
The Samsung unit has a user menu option labeled “Gamma” with seven different s<strong>et</strong>tings labeled –3 to +3<br />
with a factory default of 0. Figure 4 shows how the transfer function varies with this s<strong>et</strong>ting. The Gamma +1<br />
s<strong>et</strong>ting was used for all of the other figures and tables in this report as well as in the viewing tests because it<br />
is the closest fit to the standard gamma of 2.20.<br />
Figure 5: Transfer functions for various LG picture modes; Figure 6: Comparison of the transfer functions on a<br />
common percent of peak luminance scale<br />
Source: <strong>Display</strong>Mate Technologies and Insight Media<br />
In Figure 5 the transfer functions for the predefined daylight, normal, and night time picture modes for the LG<br />
hospitality unit are the out-of-box unmodified factory s<strong>et</strong>tings provided by LG. Given that this model has a very<br />
high peak luminance and a very low contrast ratio, these transfer functions are the opposite of what is needed to<br />
compensate for the unit’s short-comings and actually further decrease its contrast, picture quality and accuracy.<br />
The transfer functions do steepen at low signal intensities due to the very high digital black levels of 24 to 32<br />
chosen by LG instead of the standard digital level of 16.<br />
For the user mode we properly s<strong>et</strong> the black level, clipping and white point chromaticity and obtained much b<strong>et</strong>ter<br />
results. The user mode is the mode used for all of the other figures and tables in this report and also for the viewing<br />
tests. Note that the user mode luminance has been shifted downward in 9 by 40 percent to prevent crowding.<br />
The gammas for the daylight, normal, night time, and user picture modes are respectively: 1.68, 1.65, 1.52, and<br />
2.13. The transfer functions for the four large-screen units are plotted on a common 100% of peak luminance scale<br />
in order to compare their relative behavior. A pure power-law gamma with a slope of 2.20 is also plotted in black.<br />
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