Canon 10 x 30 IS User manual

10X30 IS
15X50 IS
ALL WEATHER
18X50 IS
ALL WEATHER
BINOCULARS
TECHNOLOGY GUIDE
12X36 IS
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Erecting prisms
Objective lens
Profile
Eyepiece barrel
Diopter adjustment rings
Focusing ring
Eyepiece lens
Eye cup
Image Stabilizer switch
Vari-Angle Prism
Doublet
field-flattener
Image Stabilizer switch: To activate the image stabilizer.
Eyepiece barrel: To adjust the spacing of the eyepieces to the
spacing of your eyes.
Diopter adjustment rings: To adjust the diopters to your own
eyesight.
Focusing ring: To adjust the focus.
Eyepiece lens: Enlarges the object refracted from the objective
lens. It consists of three groups of 5 lenses.
Eye cups: Protect the eyes from shock and harmful rays.
Doublet field-flattener: Makes the images sharp throughout
the field of view. This consists of two lenses.
Erecting prisms: Corrects the inverted image.
Vari-Angle Prism: System which stabilizes the image, using
Canon’s unique optical technology.
Objective lens: Pulls in the image of a distant object.
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How to Use the Binoc lars
Eye Spacing/Diopter Adustment/
Rubber Eyepieces
r
ings
ens
u
blet
e
ner
Remembering the readings of
the diopters will be convenient
to adjust the binoculars after
someone else has used them.
With the IS series, you can
simply lengthen the eye cups
by squeezing the edges of the
eye cups.
1) Look through the binoculars with
both eyes, and adjust them for the
spacing of your own eyes (with the
IS series, use the eyepiece barrels).
The instrument is correctly adjusted
once both views merge into one circle.
Next, adjust the diopter adjustment rings
to your eyesight. This is an important
step, as each person has different
eyesight.
2) With your right eye closed, look
through the left eyepiece with your
left eye. Using the focusing ring,
adjust the focus on an object.
3) Now, close your left eye and look
through the right eyepiece. If the
object is in focus, the diopter was
adjusted correctly. Otherwise, use
the right diopter adjustment ring
to readjust the focusing.
4) By adjusting the focusing ring each
time you look at an object, the
diopters will also automatically focus.
Please note that eye spacing and diopter
adjustment is different for each person.
Another person would have to adjust the
eye spacing and diopters again.
• For eyeglass wearers
If you look through the binoculars while
wearing eyeglasses, your eyes will be
further away from the eyepieces, and
scenes will gradually shade off at the
edges. To prevent this, use the foldaway
rubber eyepiece rings if available.
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(Fig. 2)
(Fig. 3)
Eyepiece lens
Objective lens
Eyepiece
lens
Porro
prisms
Objective lens
The first binoculars were invented about 400 years ago.
There are now several hundred different models of binoculars
manufactured and sold throughout the world.
Although the concept of seeing a magnified image with your
own eyes has not changed, there are two distinctly different
types of binoculars: prism binoculars and Galileo binoculars.
(Fig. 1)
Objective lens
Roof prisms
Eyepiece
lens
Q1 What Types of Binoc lars
Are There?
•Prism Binoculars
The majority of binoculars sold
today use convex lenses for both
the objective lens and eyepiece
lens. They are called prism
binoculars, because prisms are used
to “correct”the inverted image.
1) Porro Prisms (Fig. 1)
Because of the porro prisms,
the light passing through forms
a “Z”shape before reaching
the eye.
2) Roof Prisms (Fig. 2)
When using roof-shaped prisms,
called Roof (or Dach: meaning
roof in German) prisms, the light
passes through in a straight line,
which makes it possible to
design compact binoculars.
•Galileo Binoculars (Fig. 3)
The concept used in the telescopes
made by Galileo Galilei in the 17th
Century is used in these binoculars.
Because concave lenses are used
for the eyepiece lenses, prisms are
not needed to correct the images.
Also known as opera glasses, this
type is used for looking at objects
not too far away.
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b
Objective lens
a
(Fig. 4)
Eyepiece lens
Tested with the EF 300 mm f/4L and EF 24 mm f/2.8,
the outcome was pretty obvious.
n
s
e
ns
c
e
l
ens
Basically binoculars are made up of the objective lenses for long
focal points, and the eyepiece lens, for short focal points.
The light from each to the two objective lenses which forms the
image of an object (Fig 4-a), passes through the barrel and hits
the eyepiece lens, which enlarges the image (Fig 4-b).
Create a telescope using two camera lenses
Attach a wide-angle lens to a telephoto lens. Without
shifting the optical axis, look through from the back of
the lens and adjust the distance between the two lenses.
You will eventually see a sharp inverted image.
This is the basic structure of a telescope. Put two of these side
by side and you have a pair of binoculars. In addition, the
longer the focal point of the telephoto lens and the shorter the
focal point of the wide-angle lens, the more the image will be
magnified. It is also possible to achieve focus by adjusting the
distance between the two lenses. It’s very simple.
s
e
ce
Q2 Why Are the Images
Magnified?
Prism Binoculars/Galileo Binoculars/
Porro Prisms/Roof Prisms
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Q3 What Is Magnification?
With a 10x magnification binoculars,
a car 100 meters away will seem as
if it were 10 meters away.
A car 100 meters
away with the
naked eye.
A car 10 meters
away with the
naked eye.
Magnification and focal length
A 1,000 mm telephoto lens for a camera will provide five times
higher magnification than a 200 mm lens. The same applies
to binoculars, in that an object is enlarged five times more
with 20x magnification binoculars than with 4x magnification
binoculars. The only difference is that, while a telephoto lens
must be wide enough to magnify the image for the fairly
wide aperture of the camera, binoculars need only magnify the
image for the relatively smaller iris of the human eye. Say for
example you have 12x magnification binoculars. To get the
same enlarged image using a 35 mm Single lens reflex camera,
you would need to use a 700~800 mm telephoto lens.
Magnification refers to the ratio of the size as seen with the
naked eye and size obtained with the binoculars. For example,
if a pair of binoculars has 10x magnification, an object will be
enlarged 10 times. In other words, something 100 meters away
will look 10 meters away through the binoculars.
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A sharper image–right down to
the bird’s wings.
Because of lens aberration, the
entire image appears blurry.
Q4 Why Is the Image Easier to
See When Enlarged?
Image quality and resolving power
Not all binoculars will provide the magnification ratio and
resolving power indicated on the instrument. When there
is too much aberration, there is not enough resolving
power. No matter how superior the binoculars may be,
the resolving power will decrease because of image shake.
The larger the magnification ratio, the more the hands will
shake that image. In general, binoculars with magnification
of over 10x are not recommended for hand-held use.
To eliminate this problem, Canon has adopted its superior
optical technologies gained in developing camera lenses. In
addition to using the doublet field-flattener, UD lens and
aspherical lenses to achieve ideal resolving power, Canon has
used its own original image-stabilization technology (in the IS
series), which greatly controls hand shake. It is because of these
technologies that with Canon’s binoculars, each feather on a
bird’s wing comes in crisp and clear.
How clearly the binoculars let you
distinguish details is called their
resolving power. Because the unit area
of conic vision cells in the retina of a
human eye is low, no physical training
will be able to increase, up to a point,
the resolving power. The only way to
increase it is to look through a good
pair of binoculars. If you use 10x
magnification binoculars, you will have
10x more resolving power than normal.
With the naked eye, you will not be able to read text past a certain
distance, but with the binoculars, because the resolving power is
increased, you will be able to read it.
Magnification / Resolving Power
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The optical structure of each model of binoculars is different,
so even if the magnification rating is the same, how much view
the pair of binoculars can pull in will differ. The width of the
view you can see through the binoculars is called the field of
view. For bird watching in a large forest, using a wider field of
view will be more useful.
1) Real field of view
This is the view through the binoculars (Fig. 5-a), and it is
measured from the center of the objective lens and expressed
in degrees (angle). The lower the magnification the binoculars
have, the wider the real field of view—and the higher the
magnification, the narrower the field of view. Because of this, it
is hard to compare the real field of view of binoculars with that
of binoculars of different magnification rating.
2) Apparent field of view
This is the value of the real field of view multiplied by the
magnification (Fig. 5-b). For example, if 10x magnification
binoculars have a 5x real field of view, the apparent field of
view will be 50˚. This value represents the field of view which
you will see looking through the binoculars. It is comparable
even among binoculars of different magnification. In general,
if the apparent field of view is more than 65˚, it is considered
a wide field of view.
Apparent field of view = Magnification x Real field of view
3) Field of view at 1.000 meters
The field of view, measured in meters, which you can see 1.000
meters in front of you.
Field of view at 1.000 meters = 1.000 x 2 x tan (Real field of view) [m.]
(Fig. 5) Looking through 10x/5˚ binoculars at a subject 1,000 meters away
Q5 Why Are There Different Fields
of View for Different Binoc lars?
(Fig. 5)
100m(1000/10)
1000m
c Field of view at
87 meters: b Apparent field of view: 50˚ a Real field of view: 5˚
1.000 meters
100 meters(1000/10)
2
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Wide field of view
Narrow field of view
Image circle
Film format
(Fig. 6)
Lens
?
Field of view and image circle
Film for 35-mm cameras has a set standard format
(24 x 36 mm), and if the focal distance is the same, generally
the angle of the lens will not change. However, the field of view
is larger than the film, and the part of the view which is larger
than the film is called the image circle (Fig. 6). The field of
view for binoculars is usually everything inside the perimeter
of the image circle.
Field of View/Real Field of View/Apparent
Field of View/Field of View at 1.000 meters
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When bright
When dark
(Fig. 7-a)
(Fig. 7-b)
Q6 Why Are Some Binoc lars
Brighter Than Others?
The exit pupil
is 3.0 mm
The exit pupil
is 7.0 mm
Brightness varies from one model of binoculars to another.
Brightness varies with the price and size of the binoculars.
There are many degrees of brightness according to one’s needs.
1) Exit pupil
The bright circle visible when the eyepiece lens array is viewed
about 10 inches away from the eyes is called the exit pupil.
The diameter, measured in millimeters, is called pupil aperture.
The larger the exit pupil, the brighter an image the binoculars
make, and the brightness is expressed by the square of the
aperture of the exit pupil.
Human pupils are about 2-3 mm at most (Fig. 7-a) when bright,
and the binoculars’exit pupils should be about 3 mm. At night,
our pupils dilate to about 7 mm (Fig. 7-b), so it is desirable
to have binoculars with large exit pupils if they will be used
at night.
However, the disadvantage is that such binoculars tend to be
big and heavy.
2) Available Aperture of the Objective Lens
The diameter of the objective lens which the light passes
through is called the available aperture of the objective lens.
If the magnification is the same, the larger the available
aperture of objective lens, the brighter image seen through the
binoculars. This is the same effect as when a telephoto lens has
a very large lens diameter. The relationship of the three is:
Aperture of Exit Pupil = Available Aperture of Objective Lens
Magnification
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3) Twilight Coefficient
Watching a bird from a distance at night, you would use a 300
mm f/2.8 instead of a 50 mm f/1.4 lens, even if the brightness
were cut in half. The amount of gradation which the human
eyes can see is very large, and with experience, will be able
to distinguish between the colors. In this way, although the
eyes may be weaker when bright, the higher the magnification
(resolving power), the more detail the eyes will be able to
distinguish. A simple calculation rule:
Twilight Coefficient = Magnification x Available Aperture of Objective Lens
For example, if you compare the brightest binoculars for general
use, those of 7x50 (exit pupil: 7.1 mm) and 12x36 (exit pupil:
3.0 mm), the binoculars of 7x50 are brighter. But with the
twilight coefficient:
As a result, using 12x36 binoculars at night will provide more
detail.
Brightness and Lens Reflection
Even with binoculars with the same exit pupil, the brightness
may not always be the same. This is due to the amount of
light reflected by the lens. With uncoated lenses, about 8% of
incident light is reflected. The more light is reflected, the lower
the brightness of the images will be, in addition to a decrease in
Left: lens not coated. Right: lens coated. The lens
on the left looks white because light is reflected.
image quality.In order
to prevent the incident
light from being
reflected, Canon uses a
“super spectra”coating,
which has been highly
praised for its efficacy
with Canon’s EF lenses.
Canon also coats the
prisms as well to ensure
bright and clear images.
Exit Pupil/Available Aperture of Objective
Lens/Twilight Coefficient
7x50=18.7
12x36=20.8
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(the brightness is limited to a certain point)
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Q7 How Can I Tell the Difference
in Image Q ality?
The ideal binoculars are ones that make you forget you are
looking through binoculars. If you purchase a pair with a wide
field of view, and the image quality is superior (enough that
there isn’t much difference from looking with the naked eye),
you will have many enjoyable hours of use. Some people have
the misconception that because they only concentrate on the
middle of the lens, even if the outer part is blurred, it really will
not matter. Normally, the retina projects aberration-free images,
so when you view blurred images, the brain tries to disregard
them. If you consciously try to reject the blurred images for
a long period of time, there is a chance that you will become
very tired and even sick. It is very hard to determine the image
quality with just a spec sheet. The easiest and surest way is to
actually look through the binoculars. Please keep the following
points in mind when purchasing binoculars.
1) Do you see only one image or two?
Binoculars use two lenses parallel to each other. However, if
alignment during manufacture is not perfect, or owing to shock
during transport, the lenses may become just a bit off. If that
happens, you will see two images. Even if you get the binoculars
fixed, the lenses will tend to slip with just a slight jolt. Such
binoculars are not recommended.
2) Is the image sharp enough?
Make sure that the lettering on a sign or the thin branches
on trees are crystal clear (See comparative photos “Resolving
Power”on page 7). Also, make sure that the lights at night
and the stars are not blurred and the shapes are not distorted
(photo a). It may be difficult to know how clear the image is
by looking through only one pair of binoculars. Try looking
through several, and you will be able to tell the difference.
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a: Comatic aberration
The image around the light
source is blurred.
There is a yellow tint on the image.
The highlight part looks pink.
b: Chromatic aberration
c: Discoloration
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3) Does it seem as though the colors are running
together? How about discoloration?
When you look at a white object, a rainbow-type ring
appears. Called chromatic aberration, the image quality usually
decreases, and occurs with binoculars with larger apertures and
higher magnification (photo b). Also, because of the coating and
different lenses used for the binoculars, the colors may change.
Point the binoculars at a white image and check to see how
white the image is (photo c).
In order to prevent discoloration, Canon has adopted the
UD lens (15X50 IS ALL WEATHER, 18X50 IS ALL WEATHER)
from the EF lens series, which is known for its superior optical
technogy. In addition, with the “super spectra”coating, we
guarantee bright and clear images (photo d).
4) Is the entire image clear?
There are more binoculars with a wide field of view to meet
the demands of consumers. However, there are cases where the
binoculars were “forced”to have a wider field of view, which
causes the image quality around the edge of the lens to decrease.
When this happens, most of the time it is caused by curvature
of the field. Point the binoculars at a wall, focus on something
simple, and check if you can see clearly all round (photo e).
If the curvature of the field is large, the edges will be blurred.
It is not recommended to purchase such binoculars.
To greatly decrease the curvature of the field, Canon uses
a field-flattener lens and an aspherical lens. With Canon
binoculars, you will have beautiful image quality all round.
5) Is the image distorted?
When looking through the binoculars, there are times when the
perpendicular lines of windows of a building or bricks seem
warped around the edge of the lens (photo f). This is called
distortion. When the distortion is great, not only will the entire
object seem distorted, but when you move the binoculars, it will
seem as if the object were flowing, making it very hard to see.
Canon uses high-precision aspherical lenses to correct the
distortion.
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e: Curvature of the field
The colors are not vivid and
look dull.
The building is slanted,
and has a spool-shaped effect.
f: Distortion
d: Contrast
The image around the
light source is blurred.
Chromatic Aberration/Curvature of the
Field/Distortion
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Q8 What Makes Canon's IS series
so Uniq e?
Eliminated "image shake," which was a major problem
with binoculars.
Uses the most advanced image stabilizer.
Almost everybody who has ever used binoculars at sporting
events or concerts has experienced how much the images shake,
and you feel that the binoculars are useless. The main complaint
of users has been image shake. The higher the magnification,
the larger the image shake. In general, any binoculars with over
10x magnification should not be used for a long time.
The best solution in the past was to use a tripod. However,
tripods are bulky and can’t be used everywhere. Even if you
need a pair of binoculars of over 10x magnification for bird
watching, the most you would want to use since you walk
around a lot would be something of 7x or 8x magnification.
Canon is the world’s first maker to use an active optical image
stabilizer for IS series. Because two Vari-Angle Prisms
are controlled by a microprocessor, hand shake is eliminated
(Fig. 8). As a result, even with over 10x magnification, a tripod
is not needed. And they can even be used while viewing from
a moving car or train! In addition to the light weight, there is
no eye strain to make you tired, so it is possible to use these
binoculars for a long time.
(Fig. 8)
Image shake is compensated.
Without shake.
Vari-Angle Prisms
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With image stabilizer
Without image stabilizer
With the image stabilizer on, you are guaranteed stable images even from a
moving vehicle.
Image Stabilizer/Vari-Angle Prism
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(Fig. 6)
Wide field of view, with superior image quality overall.
Uses a doublet field-flattener.
The image quality around the edges is a very important point
to look at when selecting binoculars. If binoculars with inferior
image quality are used for an extended period of time, the user
will tire easily and may even become sick. The IS series use
the world’s first doublet field-flattener lens (Fig. 9). This is
Canon’s exclusive optical design with two field-flattener lenses,
lenses which are normally reserved for high-grade binoculars.
By using two lenses, Canon has achieved a wide field of view
of 67˚(12x36 IS, 15x50 IS ALL WEATHER, 18x50 IS ALL
WEATHER), with unrivaled sharpness.
(Fig. 6)
You can enjoy the power and sharp image .
Object lens
UD lens
Eye lens (Right side:
Moves when adjusting
for sight differences
between the left and
right eyes)
Moves when adjusting
the focus
Vari-angle prism
76mm
Direction of movement
of the eye lens
Roof prism
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The ALL WEATHER type is suitable for ALL WEATHER conditions - rain or shine.
Lightweight and water resistant: Excellent for outdoor use.
The bird that you were following from afar suddenly came close
to you. One problem you encounter is the closest focusing
distance. In general, the more magnification the binoculars
have, the longer the focusing distance. There are plenty of times
when you had no choice but to watch with the naked eye,
because you couldn’t focus in time.
Also, when you are bird watching, you are constantly walking
around with a pair of binoculars. For that reason, you would
like to carry around something light. 10x30 IS, despite its image
stabilizer and full size, weighs only 600 gr. Because a tripod
would weigh a couple of pounds, the burden is cut down
considerably.
The “15x50 IS ALL WEATHER”and the “18x50 IS ALL
WEATHER”are designed with a sealed construction that suits
them for outdoor use, even in the heaviest rain conditions.
They are built for ALL WEATHER action.
And what's more, because the 12x36 IS is water resistant, you
can still use it in a light drizzle. Even if it gets wet, it is still easy
to hold, because it is covered by a rubber material.
Doublet Field-Flattener Lens/ Field-
Flattener Lens/Closest Focusing Distance
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Various types and characteristics of image stabilization
technology
Presently, there are three makers, including Canon, selling
binoculars with image stabilization technology
1) Vari-Angle Prism type
Two sensors detect horizontal and vertical shaking respectively.
The two Vari-Angle Prisms in both the left and right telescopes
are controlled by a microprocessor to instantly adjust refraction
angle of the incoming light. This system is used in Canon’s IS
Binoculars.
Advantages: •Compact, light.
•Immediate response after the image stabilizer
is activated (the system is activated as soon
as the button is pressed).
•Stable image even when panning.
Disadvantage: •Requires batteries.
2) Gyro type
A high-speed motor-driven gyroscope is attached to a prism.
No matter how much the binoculars are shaken, the image will
remain stable. This system is used in Fujinon’s Stabiscope S1240
and S1640.
Advantage: •Extremely resistant to heavy shaking or
movement.
Disadvantages: •One minute delay while the 12,000 rpm motor
is starting up.
•Tend to be heavy.
•This system is unable to distinguish between
shake and panning; therefore image is not
stable when panning.
•Requires batteries.
3) Mechanical type
The prism system is tied-in with the Cardanic Suspension
system, which prevents the prisms from moving no matter how
much the binoculars are shaken. This system is used in the
Zeiss 20x60S Professional.
Advantages: •No batteries required because of mechanical
system.
•Immediate response after the image stabilizer
is activated (the system is activated as soon
as the button is pressed).
Disadvantages: •Tend to be heavy.
•This system is unable to distinguish between
shake and panning; therefore the image is not
stable when panning.
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