Tomey TCP-2000P, Руководство по эксплуатации

Страница: 86 / 113

Operation Manual
86
contrast are obtained by concurrently varying the luminance of the light
and dark bands as to keep the mean luminance unvaried.
mean L = (Lmax + Lmin) / 2
C = (Lmax – Lmin) / (Lmax + Lmin)
S = (Lmax + Lmin) / (Lmax – Lmin)
L – luminance
C – contrast
S – contrast sensitivity
Contrast Sensitivity
Line
Spatial
Frequency
1 2 3 4 5 6 7 8
Line A 1,5 4 7 12 20 35 70 120 170
Line B 3 4 9 15 24 44 85 170 220
Line C
6 5 11 21 45 70 125 185 260
Line D 12 5 8 15 32 55 88 125 170
Line E
18 4 7 10 15 26 40 65 90
Table 7. Values of the sinusoidal gratings.
5.9. Contrast Adjustment
Each optotype chart can be displayed in required contrast. Contrast level can be
adjusted from 100% to 1%.
Current contrast level is displayed continuously on the screen. If there is no
percentage information that means contrast level is set to 100%.
Contrast can be adjusted only for optotype Chart.
Contrast adjustment works also with masks (vertical, horizontal,
single, red-green, underlining).
HINT !
HINT !