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How sonar focusing works
As you beg in 10 press the shutter
button, your camera releases sound
waves
to the central part of the scene
(approximate
area marked in blue).
The frequencies are far beyond our
travel
range of hearing and
at the
speed of sou nd (1 ,100 feet per
second).
3
The split second it takes for the
sound to reach your subject and
the echo to return is fed into a tiny
electronic computer inside the
camera.
The computer uses this time mea-
surement to calculate the distance
between the camera lens and your
subject, then signais a motor to turn
the lens until your subject is in
sharp focus.
This extraordinary
chain of events
113
takes place in less than
of a
second.
. .. echo returns to camera.
--
((
((
Total Time
4
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