Focus:
A large depth of field not only ensures an appropriate image size for the faces of
the recognition targets, but also allows them to stay in focus for a longer period of time,
thereby increasing the recognition accuracy. Calibrate the lens at the telephoto end for
effective recognition at its optimal recognition distance of 4 m (13.12 ft).
Loosen the screw
Telephoto End
Figure 5-4
Range:
The recognition result is at its best when the target walks straight to the camera.
When the target deviates laterally, recognition is still possible as long as
the target stays
within a 15 degree
range. The camera is unable to recognize the faces when the
deviation exceeds 15 degrees.
<15°
Recognizable
<15°
Recognizable
>15°
Unrecognizable
Figure 5-5
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