Grass Valley TTV 1657D - Manuel (Page 137)

Chapter 2 - Camera 137
Camera operation
THOMSON TTV 1657D
User manual
B1657D902C
Septembre 2000
2.2.3 - Balances
The balances can be performed with the "SAVE-ON" switch on "ON" or "SAVE".
2.2.3.1 - Black balance
Black balance is made in two steps: black pulse adjustment and balancing of black levels.
Set the "WHT BLK" selector switch on the front of the camera to "BLK". The iris closes
automatically and the black balance cycle begins. The video levels balance and the view-
finder display reads as follows:
• - - -: "RUN" indicates that balancing is taking place. When the balance is correct, "OK"
is displayed.
• *******: if the balance is incorrect:
- TIME LIMIT: the time allotted to execute the black balance is completed and the
automatic device has not completed the adjustments,
- OVERFLOW: the corrections made are maximum and one or more settings are still
incorrect.
The following messages are displayed if the "DISPLAY" function is "ON" (Maintenance):
• UP DB: indicates the corrections made to the black pulses on the red (R), green (G) and
blue (B) videos. The values can vary between 0 and 100. If the automated device makes
few or no corrections, the values shall be equal or close to 50,
• 0 DB: indicates the values of the black level corrections to the red (R) and blue (B)
videos. The values can vary between 0 and 100. If the automated device makes few or
no corrections, the values shall be equal or close to 50.
Automatic black shading adjustment
To run a black smear automatic adjustment cycle, set selector switch "WHT-BLK" to
"BLK" for more than 3 seconds. This starts a black balance followed by automatic adjust-
ment of black shading, followed by a further black balance cycle. The complete cycle lasts
approximately 20 seconds.
B L A C K B A L A N C E
- - -
* * * * * * *
R G B
U P D B - - - - - -
0 D B - - - -
If "DISPLAY" = ON (Maintenance)