Hitachi DK-Z50 Operating Instructions Manual page 22

White and black balance adjustment
Black balance adjustment
Black balance requires adjustment in the following situations.
Equipment being used for the first time
Equipment idle for an extended period
Large change of ambient temperature
Gamma setting changed
1. Hold the R button depressed for two second. Black balance is adjusted automatically.
2. The screen displays the following messages during adjustment.
The lens iris is automatically closed.
Adjustment in progress
3. Adjustment is completed in several seconds and automatically stored in memory.
Adjustment complete
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