Page 15
2nd Edition. January, 2000
ULTRA
★
STEREO
PSA-200 Instruction Manual
Program
The Program section controls values for the
display and measurement functions (see
Fig. 12).
(Fig. 12) Program Setup
Display
Five shades of gray are used to show bright-
ness differences among the zone squares.
The “foot-Lamberts per gray step” value
sets the number of foot-Lamberts variation
between steps or displayed shades of gray.
A value of one is the default value and is
proper for most applications.
“Fit display contrast to image contrast”:
This asks the software to maximize the con-
trast of the display and to have it follow the
camera video closely. This is normally
checked.
Weave and Jitter
If the Weave and Jitter option is included
and such measurements are to be made, the
screen aspect ratio should be inserted here.
Correct calculation of the results is depen-
dant upon the aspect ratio.
Luminance
This section allows choice of display win-
dow type, either 9x5=45 zones (see Fig. 13)
or 3x3=9 zones (see Fig. 14). In the 9x5 dis-
play, the luminance value is displayed for
each zone. In the 3x3 display, the luminance
value for the center zone is displayed and
the rest of the zones show the luminance
value as a percentage of the center value
reading.
(Fig. 13) Luminance Grid 9x5
(Fig. 14) Luminance Grid 3x3
A check box is provided for the choice of
luminance data being displayed rapidly as
measured or after filtering. The filtered data
is updated more slowly and is easier to read.
Camera
This section sets the measurement range
of the camera and display. It also will ad-
just the data to compensate for the vertical
angle-of-view when the camera is positioned
in the projection booth.
The nominal measurement range of the PSA-
200 is three to 30 foot-Lamberts. With the
addition of an optional ND1 neutral density
filter, the range can be changed to 30 to 300
foot-Lamberts. The PSA camera is normally
set to read luminance in the audience area.
If the camera is situated in the projection
booth, there is a vertical angle between the
audience view of the screen and the view
from the projection booth. This causes the
apparent centering of the light pattern on
the screen to move upward. If this apparent
