Grass Valley DD35 Family v.3.1.5 - Manual (Page 223)

3. Menu Operation DD35 Production Switcher
3 – 71 Operating Instructions – Rev. 16 / 10.2001
3.7.5.3 Manual optimization of critical pictures
Selectivity L (left), Selectivity R (right) and Lum Sel enables the user to change
the selectivity manually.
This may be required for the following reasons:
D
The user wants another compromise between color fringes and density of the
foreground object.
D
Size and focus of the foreground object were not sufficient.
D
Blue spill has to be removed from the foreground object.
D
The picture only contained the key color and no foreground object.
The selectivity separates the foreground colors from those without key color com-
ponent. The attributes Left and Right refer to the neighborhood to the key color on
a vectorscope. Lum Sel refers to the luminance dependence of the gray mixed
color in transition areas.
Thus, incase the key color is Blue, the selectivity adjustment influences the follow-
ing colors:
D
Selectivity L, the reddish neighboring colors
D
Selectivity R, the greenish neighboring colors
D
Lum Sel, the gray/yellow colors.
Direction of rotation of the controls:
The influence of the foreground is increased when Selectivity L is turned left and
Selectivity R is turned right.
When Selectivity L is at the right stop and Selectivity R is at the left stop, a very
high selectivity (i. e. narrow band color selection) is set.
With Lum Sel Y = 50% (center position after automatic run), this parameter is with-
out influence on the picture. Higher values (cw rotating) deprive gray edges in-
creasingly by the key color, thus coloring them complementarily. A gray halo in yel-
low (blond) hair becomes yellow (blond) again when its gray was effected by mixing
yellow and blue key colors.
Adjustment of the selectivity should be just so much that the key color portion on
the foreground object has disappeared. Doing so, a slight ”keying” of the fore-
ground object may be noticed.