How To Attain Better Images; Black Balance Adjustment - Hitachi HV-D25 Operation Manual

How to Attain Better Images

Black Balance Adjustment

Adjust black balance to provide proper color tone at a dark part of video image.
be sure to carry out black balance adjustment.
When using the camera first after purchasing it.
When using the camera after it has been unused for a long time.
When the camera operating environment is changed (e.g., when the ambient temperature varies
significantly).
Under normal condition, it is not required to make black balance adjustment at power-on.
1. In the Direct mode, hold the ABB button pressed for about 2 seconds for automatic black balance
adjustment. With MESSAGE RTN:ON, AUTO BLACK appears. At the end of successful adjustment
AUTO BLACK:OK appears.
(Notes) 1) Where the lens having the auto iris function is used, the iris is closed automatically during
adjustment. Sometimes occurs when adjusted with the lens iris in the manual mode
(lens iris switch set to M). Open the iris for better exposure.
2) In combinational use with the manual iris lens or microscope, a full-black screen image is
provided from the CCD image sensor during adjustment. When picturing after adjustment,
a white screen image appears momentarily. This phenomenon is not a symptom of trouble,
however.
3) In case that the manual iris lens is used, do not attempt auto black balance adjustment
while taking an image of subject having extremely high luminance such as the sun. This
may deteriorate black balance accuracy.
If black balance adjustment cannot be made, any one of the following messages will appear. Take a
2.
proper procedure according to the error message, and then try black balance adjustment again.
Error message
AUTO BLACK NG
CHANGE TO CAM
TRY AGAIN
AUTO BLACK NG
IRIS NOT CLOSE
TRY AGAIN
AUTO BLACK NG
???
TRY AGAIN
Turn off the color bar.
Close the lens iris.
Avoid taking an image of subject having high luminance such as the sun, or
decrease illumination on the microscope.
Carry out ABB again. If this message appears in repeated attempts, it is
necessary to inspect the inside of the camera. In this case, notify your local
Hitachi Denshi sales agent or Hitachi Denshi service office
Procedure
In the following cases,
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