Canon EOS Rebel XTi Instruction Manual page 216

@l Ccrnero shake _
IS
camera
camera
causes
it
Image
Sta;'iII';'~
Pa,allel Mo';"ment
P;i~~IPle
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i.
Lens When still
Focal plane
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Siabib:er Unil
Canon IS Lenses detect camera shake with a pair
of
built-in gyro sensors, shifting lens components in
the direction of the vibration to counteract it and
prevent blurring. When the shutter button is pressed
halfway while the IS function is on, compensation
for camera shake is activated in just
0.5
seconds.
Since the potential optical performance of the lens
is optimized, you can capture beautiful images.
Perhaps you've encountered blurred images when enlarging pictures: photos that look fine in
smaller postcard sizes appear quite fuzzy at greater size. In fact, camera shake happens more
frequently than you'd think. There are several reasons for accidental blurring. One cause is the use
of
a telephoto lens, which lets you shoot smail subjects at higher magnification, and also turns small
vibrations during shooting into heavy blurring of images. Another cause is shooting in dark places.
When taking pictures at lower shutter speeds, in an unsteady posture, or on an unstable platform
such as a train or a boat, blurring is quite common.
I
~
Image Stabilizer can be used within 0.5 sec.
I
after you press the shutler button halfway.
• To avoid camera shake, the general rule is to use a shutler speed .
tlla! is the reciprocal of lhe
focal
length (1/focallength
x 1.6).
!
• There
will be
a 90% or higher chance of the shot not being blurred by camera shake.
I
Image Stabilizer ON
50
r-"~';~~'~';=~~mm
f/4-5.6IS USM Image
~tabiliZ~~"'"
I
Effect Graph (f ::: 85mm)
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(o/.,)
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;.... . . .
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.....
.A,PPE~X~c3 stops . .J
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,
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,
Image Stabilizer , /
OFF /
/
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o
L . . - - ' - - - - i - - - - ' - - - - - - - - i - -
iia
1/15 1/30 1/60
11125 (sec)
Generally, the shutter speed that allows photographers to shoot photos without blurring is "1 /focal iength
H
•
of course,
the faster the shutter speed, the greater the benefit in blur reduction. In comparison with lenses that lack an image
stabilizer
i
Canon
is
Lenses can achieve the same
blur-free
clarify
at shutter speeds that are 2 to 3 stops
(increments) slower. Lers take a look at an U-S 17-
85mm
f/
4-5.6 IS
USM
lens, for example. Since the
maximum focal length of this lens is effectively
136mm with cameras* like the
EOS
Digital Rebel
XT
I
EOS
350D Digital and others that feature APS·C
image sensors, the slowest shutter speed that could
normally be used while maintaining a blur-free
image is 1/1 25 sec. However, when the IS function
is activated, the shutter speed can be reduced 3
stops to 1/15 sec. without blurring. Thus, you can
shoot subiects at slower shurter speeds without fear
of blurred images - dramatically expanding your
range of shooting situations and photo variations.
The most certain way to prevent camera shake is the use of a tripod. Additionally, use of flash can
effectively minimize blurring when shooting in low lighting conditions. However, Ws inconvenient to
corry around a heavy, bulky tripod, and in some places, tripod use isn't even allowed. What's
more, the use
of
a flash may sometimes spoil the mood of a shooting scene
by
disrupting the
natural lighting nuances of the atmosphere. In any
of
these situations, Conon IS Lenses are the
definitive solution to blurring problems. Just a single IS lens con help you capture images in a
natural light, without other equipment or special set-up, wherever and whenever you want.
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* ECS 20[)
reos
20Da, [OS Oi9,IOI ReD'';, Xi
!
f::OS 350D Dig;;,,,,
reos
Digiici Rebel/EO:; 3000 Digix;i
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