68
Glossary (cont.)
∫
Focus
If you look at an object through a magnifying glass
and move it closer or further away from your eye,
you will reach a point where the object becomes
clearly visible. Being focused or in focus means
that the subject can be seen with optimum clarity
and sharpness.
Human Eyes
Human eyes have lenses as well, and when we
look at objects at different distances, the shape of
these lenses changes automatically so that we
can always see these objects clearly.
Movie Camera
The image of the subject enters the Movie
Camera through the lens and is converted into an
electric signal (video signal) for recording onto
magnetic tape. The focus is adjusted either
manually or automatically by moving a focusing
lens.
Auto Focus Adjustment
The Auto Focus System automatically moves the
internal focusing lens forward or backward and
adjusts the focus so that the subject can be seen
clearly.
The Auto Focus Adjustment has the following
characteristics:
≥
It adjusts until the vertical contours of the subject
are as sharp and clean as possible.
≥
It adjusts the focus on the subjects with strong
contrast.
≥
It adjusts the focus on the subject in the centre
of the
°
LCD Monitor or Viewfinder.
Unlike human
eyes, the lens of the Movie Camera cannot
instantaneously change the focus from a nearby
to a distant subject and vice versa.
°
LCD Monitor:
NV-VZ14/VZ15 only
For the following subjects and recording
situations, the Auto Focus system cannot
provide precise adjustment. Use the Manual
Focus Mode instead. (p. 46)
1
Recording subjects with a part of it near the
Movie Camera and another part far away
from it
As the Auto Focus adjusts on the centre part of
the image, it is often impossible to bring the
nearby and distant parts of the subject into
focus.
When you want to record a person with a
distant mountain in the back, it is not possible
to focus on both.
2
Recording subjects behind glass covered
with dirt or dust
As the focus is adjusted on the dirty glass, the
subject behind the glass is out of focus. When
recording a subject across a street on which
cars are running, the focus may be adjusted on
the cars.
3
Recording subjects in dark surroundings
As the amount of light information entering
through the lens is greatly reduced, the Movie
Camera cannot adjust the focus precisely.
4
Recording subjects surrounded by objects
with shiny surfaces or much light reflection
As the Movie Camera adjusts the focus on
objects with shiny surfaces or much light
reflection, the subject may go out of focus.
Therefore, when recording at a lake or the sea,
evening scenes, fireworks, or under special
types of lighting, the subject may be out of
focus.
5
Recording fast-moving subjects
As the internal focusing lens is moved
mechanically, it cannot follow fast-moving
subjects without delay.
Therefore, subjects like children running back
and forth may temporarily go out of focus.
6
Subjects with weak contrast
As the Movie Camera adjusts the focus based
on vertical contours in the picture, subjects with
little contrast such as a white wall may be out
of focus.
