Swann PRO Serie Manual De Instrucciones página 3

Adjusting the Lens
FOCUS: The right hand dial controls the focus.
Adjusting the focus control is kind of like trying
on a different pair of glasses - it can make sharp
things look blurry and blurry things look sharp.
It's not quite magic, but it's pretty close.
Basically, once you've set the zoom, twist the
focus knob until what you want to see doesn't
look blurry anymore. If you can't turn the knob
any more one way, go back the other.
You can only have so much in focus at once -
photographers refer to the size of the area in
focus as the "depth of field".
The diagram to the right shows a couple of
different focusing options. The shaded areas
represent the depth of field. As you can see,
there is no hard edge, some things are "more"
in focus than others.
Note that this is for illustrative purposes only - there are many factors which contribute to depth of
field which vary from location to location.
A: The lens is at its widest, and focused on an
area relatively close to the camera. The depth of
field is quite large.
B: The lens at its widest with focus set to
"infinity". Anything in the shaded section will
be in focus, and this focus extends to infinity
(that is, things in the far distance will also be in
focus). However, things in the distance might be
too small to see the detail you require.
23°
81°
The zoom and focus controls are located on the
rear of the camera.
ZOOM: The left hand dial controls the level of
zoom. You can vary the viewing angle between
23° and 81°. This is an approximately 4x
(2.8mm-12mm) optical zoom, which operates
in a similar manner to the zoom on your digital
camera. Basically, zooming in makes everything
appear to be larger, at the expense of the
viewing area.
Check out the diagram to the left for a visual
representation of the zooming process.
The smaller viewing angle (marked 23°)
represents the camera's view when "zoomed
in", and the larger angle (81°) represents the
camera's view when "zoomed out".
You can set the zoom to either of these
extremities, or anywhere in between.
When you change the zoom, you'll also
have to change the focus. Why? Lenses are
complicated, and all the bits are joined together.
Changing the zoom will also change the focus.
A
B
C: The lens at its tightest, focused on an area
close to the camera. As you can see, the more
the lens is zoomed, the smaller the depth of
field becomes.
D: The lens at its tightest with focus further from
the camera. At this distance, the actual depth
of field is much larger, but it doesn't extend to
infinity like it does when the lens is wide.
C
D
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