Broadcast Lens Technology Part 2

Dr. Mohieddin Moradi
mohieddinmoradi@gmail.com
Dream
Idea
Plan
Implementation
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https://www.slideshare.net/mohieddin.moradi/presentations
2

− Vertical and Horizontal Fields of View
− F-Stop, F-Number, T-Number, , Minimum Illumination and Sensitivity
− Color Temperature Adjustment and Color Conversion in Camera
− Camera Beam Splitter Structure and Related Issuers
− Depth of Field, Depth of Focus & Permissible Circle of Confusion
− Broadcast Zoom Lens Technology
− 4K Lens Critical Performance Parameter
− Optical Accessories and Optical Filters
Outline
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Optical Terminology Related to Light Passing through a Lens

Dispersion
– A phenomenon whereby the optical properties of a medium vary according to the wavelength of light
passing through the medium.
– When light enters a lens or prism, the dispersion characteristics of the lens or prism cause the index of
refraction to vary depending on the wavelength, thus dispersing the light.
– This is also sometimes referred to as colour dispersion.
6

Refraction
– A phenomenon whereby the propagation direction of a ray of light
changes when the light passes from one medium such as a vacuum
or air into a different medium such as glass or water, or vice versa.
– When light passes through glass, the path it follows gets bent.
– The angle of refraction depends on the light’s wavelength, which
determines its color.
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𝑛 = sin 𝑖/sin 𝑟
“n” is a constant which is unrelated to the light ray’s
angle of incidence and indicates the refractive index
of the refracting medium with respect to the medium
from which the light impinges.

Diffraction
– A phenomenon in which light waves pass around the edges of an object and enter the shadowed area of
that object, caused because of the wavelike nature of light.
– Diffraction in a photographic lens is known for causing flare (diffraction flare) which occurs when light rays
bend around the edges of the diaphragm.
8

Diffraction
– Although diffraction flare tends to appear
when the diaphragm diameter is smaller than
a certain size, it actually depends not only on
the diameter of the diaphragm but also on
various factors such as the wavelength of the
light, the lens’s focal length and the aperture
ratio.
– Diffraction flare causes reductions in image
contrast and resolution, resulting in a soft
image.
– The laminated diffraction optical elements
control the direction of the light by
intentionally creating diffraction.
9

Reflection
– Reflection differs from refraction in that it is a phenomenon which causes a portion of the light striking the
surface of glass or other medium to break off and propagate in an entirely new direction.
– The direction of propagation is the same regardless of wavelength.
– When light enters and leaves a lens which does not have an antireflection coating, approximately 5% of
the light is reflected at the glass-air boundary.
– The amount of light reflected depends on the glass material’s index of refraction
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Focal Point, Focus
– When light rays enter a convex lens parallel to the
optical axis, an ideal lens will converge all the light rays
to a single point from which the rays again fan out in a
cone shape. This point at which all rays converge is
called the focal point.
– In optical terminology, a focal point is further classified
as being the rear or image-side focal point if it is the
point at which light rays from the subject converge on
the film plane side of the lens.
– It is the front or object-side focal point if it is the point at
which light rays entering the lens parallel to the optical
axis from the focal plane side converge on the object
side of the lens.

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Focal Length
– When parallel light rays enter the lens parallel to the optical axis, the distance along the optical axis from
the lens’ second principal point (rear nodal point) to the focal point is called the focal length.
– In simpler terms, the focal length of a lens is the distance along the optical axis from the lens’ second
principal point to the focal plane when the lens is focused at infinity.
Focal Length of Actual Photographic Lens

13
Principal Point
– The focal length of a thin, double-convex, single-
element lens is the distance along the optical axis
from the center of the lens to its focal point.
– This center point of the lens is called the principal
point. However, since actual photographic lenses
consist of combinations of several convex and
concave lens elements, it is not visually apparent
where the center of the lens might be.
– The principal point of a multi-element lens is
therefore defined as the point on the optical axis
at a distance equal to the focal length measured
back toward the lens from the focal point.

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Principal Point
– The principal point measured from the front focal
point is called the front principal point, and the
principal point measured from the rear focal
point is called the rear principal point.
– The distance between these two principal points
is called the principal point interval.

15
Image Circle
– The portion of the circular image formed by a lens that is sharp.
– Interchangeable lenses for 35mm format cameras must have
an image circle at least as large as the diagonal of the 24 x
36mm image area.
• EF (Electro-Focus) lenses therefore generally have an image
circle of about 43.2mm diameter.
• TS-E ("Tilt Shift Electronic") Lenses, however, are designed with
a larger image circle of 58.6mm to cover the lens’s tilt and shift
movements.
• EF-S lenses (The -S of EF-S stands for “Small image circle”)
feature a smaller image circle than other EF lenses, to match
the diagonal of the APS-C sized image sensor of EF-S
compatible digital SLR cameras.

16
Aperture Ratio
– A value used to express image brightness, calculated by dividing the lens’ effective aperture (D) by its
focal length (f).
– Since the value calculated from D/f is almost always a small decimal value less than I and therefore
difficult to use practically, it is common to express the aperture ratio on the lens barrel as the ratio of the
effective aperture to the focal length, with the effective aperture set equal to 1.
– The brightness of an image produced by a lens is proportional to the square of the aperture ratio.
– In general, lens brightness is expressed as an F number, which is the inverse of the aperture ratio (f/D).

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Numerical Aperture (NA)
– A value used to express the brightness or resolution of a lens’ optical system.
– The numerical aperture, usually indicated as NA
where 𝟐𝜽 is the angle (angular aperture) at which an object point on the optical axis enters the entrance
pupil and 𝑛 is the index of refraction of the medium in which the object exists.
– Although not often used with photographic lenses, the NA value is commonly imprinted on the objective
lenses of microscopes, where it is used more as an indication of resolution than of brightness.
– A useful relationship to know is that the NA value is equal to half the inverse of the F number.
• For example, F 1.0 = NA 0.5, F 1.4 = NA 0.357, F2 = NA 0.25, and so on.
𝑁𝐴 = 𝑛 × sin 𝜃

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Optical Axis
– A straight line connecting the center points of the spherical surfaces on each side of a lens. In other
words, the optical axis is a hypothetical center line connecting the center of curvature of each lens
surface.
– In photographic lenses comprised of several lens elements, it is of utmost importance for the optical axis of
each lens element to be perfectly aligned with the optical axes of all other lens elements.
– Particularly in zoom lenses, which are constructed of several lens groups that move in a complex manner,
extremely precise lens barrel construction is necessary to maintain proper optical axis alignment.

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Principal Ray
– A light ray which enters the lens at an angle at a point other than the optical axis point and passes
through the center of the diaphragm opening.
– Principal light rays are the fundamental light rays used for image exposure at all diaphragm openings from
maximum aperture to minimum aperture.
Parallel Pencil of Rays
– A group of light rays traveling parallel to the optical axis from an infinitely far point. When these rays pass
through a lens, they converge in the shape of a cone to form a point image within the focal plane.

20
Paraxial Ray
– A light ray which passes close to the optical axis and is inclined at a very small angle with respect to the
optical axis.
– The point at which paraxial rays converge is called the paraxial focal point.
– Since the image formed by a monochromatic paraxial ray is in principle free of aberrations, the paraxial
ray is an important factor in understanding the basic operation of lens systems.
Distance of Incidence
– Distance from the optical axis of a parallel ray entering a lens.

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Aperture/Effective Aperture
– The aperture of a lens is related to the diameter of the group of light rays passing through the lens and
determines the brightness of the subject image formed on the focal plane.
– The optical aperture (also called the effective aperture) differs from the real aperture the lens in that it
depends on the diameter of the group of light rays passing through the lens rather than the actual lens
diameter.
– When a parallel pencil of rays enters a lens and a group of these rays passes through the diaphragm
opening, the diameter of this group of light rays when it enters the front lens surface is the effective
aperture of the lens.

22
Stop/Diaphragm/Aperture
– The opening which adjusts the diameter of the group of light rays passing through the lens.
– With modern camera lenses, aperture adjustment is commonly controlled by operating an electronic dial
on the camera body.
Circular Aperture Diaphragm
– With normal aperture diaphragms, closing the aperture causes its shape to become polygonal.
– A circular aperture diaphragm, on the other hand, optimizes the shape of the blades to achieve a nearly
perfect circle even when considerably stopped down from the maximum aperture.
Photography with a lens that is
equipped with a circular aperture
diaphragm achieves a beautiful
blur effect for the background,
because the point source is circular.

23
Entrance Pupil/Exit Pupil
– The lens image on the object side of the diaphragm, i.e. the apparent aperture seen when looking from
the front of the lens, is called the entrance pupil and is equivalent in meaning to the lens’ effective
aperture. The apparent aperture seen when looking from the rear of the lens (the lens image on the image
side of the diaphragm), is called the exit pupil.
– Of the light rays from a certain subject point, the effective light rays which actually form the image create
a cone of light rays with the subject point being the point of the cone and the entrance pupil being the
base of the cone.
Entrance
Pupil
Exit
Pupil
Diaphragm

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– At the other end of the lens, the light rays emerge in a cone shape with the exit pupil forming the base of
the cone and the point of the cone falling within the image plane.
– The entrance and exit pupils have the same shape as the actual diaphragm and their size is directly
proportional to that of the diaphragm, so even if the construction of the lens system is not known, it is
possible to graphically illustrate the effective light rays which actually form the image as long as the
positions and sizes of the entrance and exit pupils are known.
– Thus, knowledge of the entrance and exit pupils is indispensable when considering performance factors
such as the total amount of light entering the lens, the manner in which the image blurs and aberrations.
Entrance
Pupil
Exit
Pupil
Diaphragm

25
Exit Pupil
– The exit pupil refers to the (virtual) image of the diaphragm formed by the lenses behind the diaphragm.
– The amount of shading is related to the exit pupil of the lens, so white shading has to be readjusted when
a lens is replaced by a lens with a different exit pupil distance.

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Angular Aperture
– The angle between the subject point on the optical axis and the diameter of the entrance pupil, or the
angle between the image point on the optical axis and the diameter of the exit pupil.

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– A lens has two principal points, called primary principal point and the secondary principal point.
– For a thin lens, both point are at the center of the lens.
– The plain perpendicular to the optical axis at a principal point is called a principal plain.
• A ray incident on the primary principal plane parallel to the optical axis will leave the secondary
principal plane at the same height, travelling toward the focal point. (Ray 1)
• An incident ray directed toward the primary principal point will leave the secondary principal point at
the same angle. (Ray 2)
1
𝑎
+
1
𝑏
=
1
𝑓

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– The minus sign in the magnification equation indicates that the image is inverted.
– If the subject is so far away that the focal length is negligible in comparison with the object distance, the
magnification can be found from the following similar formula:
– The principal points do not have to be inside the lens system; they may be located outside it.
– A lens in which the secondary principal point is behind the lens is called a retrofocus lens.
• The retrofocus type is suited for wide-angle lens systems.
– If the secondary principal point is located in front of the lens, the lens is a telephoto type lens.
– The principal points of a zoom lens move forward when the lens is zoomed.
• At the wide-angle end zoom, the lens is of retrofocus type.
• At the telephoto end, it is nearly of telephoto type.
𝛽 = −
𝑏
𝑎
𝛽 = −
𝑓
𝑎

Light Distribution at Wide angle and Telephoto Lenses
− Less light reaches the edges of the image than the center.
− Stopping down the lens improves the light distribution.
− At Wide-End, the center is flat but there is a rapid fall-off at the corners.
− At Tele-End, there is a gentle drop-off toward the corners.
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Light distortion at wide angle Light distortion at telephoto

– Light rays entering the lens from the edges of the picture area are partially blocked by the lens frames in
front of and behind the diaphragm, preventing all the rays from passing through the effective aperture
(diaphragm diameter) and causing light fall-off in the peripheral areas of the image.
– This type of vignetting can be eliminated by stopping down the lens.
Vignetting
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Vignetting
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– If you open the stop and peer into the lens from the center, the entrance pupil will look round, but if you
peer in at an angle, the entrance pupil will appear to have an oval shape, because the lens barrel
eclipses part of the marginal light.

– The cosine law, also called the cosine law, states that light fall-off in peripheral areas of the image
increases as the angle of view increases, even if the lens is completely free of vignetting.
Cosine law
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Peripheral Light Reduction According to Cosine Law
– The peripheral image is formed by groups of light rays
entering the lens at a certain angle with respect to the
optical axis, and the amount of light fall-off is
proportional to the cosine of that angle raised to the
fourth power.
– As this is a law of physics, it cannot be avoided.
However, with wideangle lenses having a large angle
of view, decreases in peripheral illumination can be
prevented by increasing the lens’ aperture efficiency
(ratio of the area of the on-axis entrance pupil to the
area of the off-axis entrance pupil).

Flare
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– Light reflected from lens surfaces, the inside of the
lens barrel and the inner walls of the camera’s mirror
box can reach the film or image sensor and fog part
or all of the image area, degrading image sharpness.
– These harmful reflections are called flare.
– Although flare can be reduced to a large extent by
coating the lens surfaces and using anti-reflection
measures in the lens barrel and camera, flare cannot
be completely eliminated for all subject conditions.
– It is therefore desirable to use an appropriate lens
hood whenever possible.
– The term “flare” is also used when referring to the
effects of blurring and halo caused by spherical and
comatic aberration.

– A type of flare occurring when the sun or other
strong light source is included in the scene and a
complex series of reflections among the lens
surfaces causes a clearly defined reflection to
appear in the image in a position symmetrically
opposite the light source. This phenomenon is
differentiated from flare by the term “ghost” due
to its ghost-like appearance.
– Ghost images caused by surface reflections in
front of the aperture have the same shape as the
aperture, while a ghost image caused by
reflections behind the aperture appears as an
out-of-focus area of light fogging.
Ghost Image
34

– Since ghost images can also be caused by strong
light sources outside the picture area, use of a
hood or other shading device is recommended
for blocking undesired light.
– Whether or not ghosting will actually occur when
the picture is taken can be verified beforehand
by looking through the viewfinder and using the
camera’s Depth of Field check function to close
down the lens to the actual aperture to be used
during exposure.
Ghost Image
35

Normal, Wide and Telephoto Lenses
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Normal Lens Wide Lens Telephoto Lens

Normal View, Wide Angle View and Narrow Angle View (Telephoto Lens)

Normal View, Wide Angle View and Narrow Angle View (Telephoto Lens)
Normal View
• The normal lens shows a vista and a perspective that are similar to what
we actually see.
Wide Angle View
• The wide-angle lens shows a wide vista, with the faraway objects
looking quite small.
Narrow Angle View (Telephoto Lens)
• The narrow angle, or telephoto lens shows only a narrow portion of the
scene, with the background objects appearing much larger relative to
the foreground objects than in a wide angle view.
• The tugboats now look much closer together.
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The shorter the lens...
The more in the picture...
The smaller the subject
The longer the lens...
The narrower the angle...
The less in the picture...
The larger the subject
The wider the angle...
Wider Angle Narrower Angle

The Narrow Angle Lens Compresses Space
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Normal-angle
Narrow-angle

Movement in Wide Angle and Narrow Angle
Wide Angle
− Good dolly lens; it de-emphasizes camera jitter and wobble.
− Objects moving toward or away from the camera have their speed greatly accelerated.
Narrow Angle
− Objects moving toward or away from the camera seem to move much more slowly.
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Narrow-angle vs. Wide-angle

Extreme Long Shot (ELS)
• Depicts a vast area from a great
distance
Long Shot (LS)
• Takes in the entire area of the action
Medium Shot (MS or MED)
• An intermediate shot recording the
players from the knees or waist up
Close-Up (CU)
• Anywhere from showing the head and
shoulders to a facial area showing only
the eye’s down to the lips
Camera Shots
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− Zoom is a function that allows an area of the image to be enlarged, so more details of it can be clearly.
– A zoom lens is a lens that can be changed in focal length continuously without losing focus. The name
comes from the strong visual impression that results, as if the viewer were zooming skyward in a fighter
plane.
– It is important to note that the amount of light directed to the imager also changes with the zoom position
change.
– The larger the zoom value, the less light reflected from the subject (because the framed area is smaller),
and the darker the image identified.
– Since chromatic aberration and other light-diffusion characteristics change when focal length (zoom
position) is changed, zoom lenses use a series of compensation lenses, which accounts for their costs.
Zoom Lens
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Zoom Ratio
Zoom ratio represents:
− The ratio between a lens’s maximum
focal length at its telephoto (zoom-in)
position and minimum focal length at
its wide-angle (zoom-out) position.
Example:
− Zoom ratio can be described as 10x or
16x as a result of dividing the former by
the latter.
45

48
Basic Composition of Zoom Lenses

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Aperture

50

51

52

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Nikon 1200-1700mm f/5.6-8P IF-ED Lens

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How Does a Zoom Lens Zoom in on or Back From an Image?
• Changing the distrance from the lens to
the object changes the size of the image.
• The position where the image is formed
also changes, so the image has to be
refocused each time the lens is moved.
• If two lenses are combined, by
moving them in coordination it is
possible to change the
magnification without destroying
the focus.
• This type of configuration, with a
group of divergent and a group
of convergent lenses, is used in
the 35-70 mm zoom lens for film
photography, which has a small
zoom ratio.

Principle:
− Changing the distance from
the lens to the object changes
• The size of image (OK).
• The position of image
(NOK).
− So the image has to be
refocused each time the lens is
moved.
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Changing the Image Position by Changing Object Distance

Principle:
− If two lenses are combined and moving relative to each other, the magnification can be changed without
destroying the focus.
Same as before with correct image size but with 2 lenses
Same as above but with correct image size and position
57

– The zoom lenses used in television broadcasting cameras are more complex, but the basic principle
remains the same—move one part of the lens system to change the size of the image, and move another
part to keep it in focus.
– A zoom lens therefore has at least two moving parts.
• The part that moves to change the image size is called the variator.
• The part that moves to maintain focus is called the compensator.
58

– Figure shows the optical path of a hand-held
zoom lens, which has a four-part structure.
– The first group is called the focusing group,
because it is used to focus the image.
– The second group of lenses is the variator that
changes the image size.
– The third group is the compensator that
maintains the focus.
– The fourth group is a stationary lens group
called the relay lens.
59

60
Beam Splitting
Prism
Beam Splitting
Prism
Relay Group
Relay Group
Zoom Group
Zoom Group
Focusing
Group
Focusing
Group

– At the wide-angle end of the zoom, the
variator (the divergent lens component) is
brought forward, creating a retrofocus type of
lens structure.
– At the telephoto end, the variator is moved
back, so the lens structure resembles the
telephoto type.
– To keep the image in the same position as the
two lens groups move, the lens groups must
move along precise curves determined by
the laws of geometric optics.
61
Lens positions at wide-angle and telephoto ends of zoom

– The motion of the variator and compensator is controlled
by the barrel cam mechanism.
– The inner barrel has a linear guide groove (linear cam),
and the outer barrel has a curved cam groove matching
the track of the lens motion (curved cam).
– When the outer, curved cam barrel is turned, the variator
and compensator move following the curved cam
grooves.
– If the correct cam curve is not followed precisely, focus
will be lost during zooming. The cams are therefore
machined to micron tolerances by numerically controlled
machine tools.
62

– The hand-held zoom lens shown as an example above has a divergent variator and a divergent
compensator. The track followed by the compensator takes it forward, then back.
63
Various Zoom Systems
– This zoom system was invented around 1955 by a
Canon optical design engineer who has since
become a Canon president, Yamaji, Eminently suited
for compact zoom lens applications, it has been
widely used.
– As another example, figure shows a zoom lens for
studio use. Here the variator is divergent, the
compensator is convergent, and the compensator
moves in only one direction.
– A number of other zoom systems are possible. For
example, there can be more than just two moving
groups of lenses.
Optical path of studio zoom lens
Other types of zoom lens

– A zoom lens must also correct optical aberration so that the image will stay sharp when zoomed.
– The path of the light rays through the lenses undergo complex changes during zooming.
– To correct aberration at all focal lengths, the aberrations caused by each of the lens groups must be
minimized, and the aberrations that the individual lens groups cannot correct on their own must be
carefully balanced so that one lens group corrects another.
– To suppress aberrations, a television zoom lens uses many more component lenses than a film camera
lens.
– Designing a zoom lens requires a great deal of ray tracing.
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Aberrations Suppression

Zoom Lens Function, Example
The imager has to be refocused each time the lens is moved
65
Principle:
− Changing the distance from the lens to the
object changes
• The size of image (OK).
• The position of image (NOK).
− So the image has to be refocused each time
the lens is moved.

Zoom Lens Function, Example
Principle:
− If two lenses are combined and moving relative to
each other, the magnification can be changed
without destroying the focus.
• This type of configuration, with a group of
divergent and a group of convergent lenses,
is used in the 35-70 mm zoom lens for film
photography, which has a small zoom ratio.
• The zoom lens for broadcast cameras are
more complex, but the basic principle
remains the same.
66

Zoom Moving Group
− Variator (divergent lens component):
• The part that moves to change the image
size (Sensor size is constant).
− Compensator:
• The part that moves to maintain focus
during zoom.
Zoom Lens Function
67

Front Focusing group:
− It is used to focus the image.
Relay group:
− It is stationary and correct light path
− The rear relay group picks up the
image from the zoom group and
relays it to the camera sensor.
− It is used to maintain the image the
correct distance from the back of
the lens and onto the pickup
device.
Zoom Lens Function
68

– In seeking longer focal ranges for the box
field and studio lenses and some of the
longer focal length portable lenses,
challenges in achieving the requisite
zooming speeds while also achieving UHD
performance were escalated.
– This called for a radical new design
approach to the zooming optical subsystems.
The central goals were to achieve greater
control over multiple lens aberrations to help
ensure full 4K performance while at the same
time expediting an increase in the speed of
the zooming action (when the digital drive
unit is set to maximum zoom speed).
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Zoom Lens Function

– Focus is achieved when the center of the returning infrared beam falls on the optical axis. There is no
parallax, and the system is highly accurate because it works by zero detection.
– The infrared light is projected and received by infrared reflecting mirrors placed behind the focusing
lenses.
– When the lens is correctly focused, the light reflected from the subject returns to a sharp spot at the
center of the optical axis of the photosensor.
– If the focus is too close or too distant, the spot image on the sensor is defocused and moves in the
opposite direction.
– The direction of shift of the focusing lens and the condition of focus can be detected by determining the
direction of movement of the center of the spot on the photosensor surface.
– Since the distance-measuring optical path is separated behind the focusing lens, zooming and aperture-
stopping have no effect on the measurement.
– Autofocusing is always performed with the most stringent focusing precision, namely at long focal length
and full aperture. 71
Auto Focus

72
Through -The –lens /Active Autofocus System
Auto Focus

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Auto Focus
Through The Lens (TTL) Secondary Imaging Phase
Difference Detection Method
– The Secondary Imaging Phase Difference
Detection Method, also used in single lens reflex
EOS camera lenses, was adopted for broadcast
autofocus systems.
– As a result of this Method, Canon’s Auto Focus
System has excellent focusing accuracy within
the entire zoom range, along with outstanding
focusing speed.
– Due to high performance servo motors, tracking
a moving object at high speed can be possible
even from a largely out of focus state.

74
Through The Lens (TTL) Secondary Imaging Phase Difference Detection Method
• With this method, light rays are split via a secondary imaging lens and directed to a pair of line sensors.
• From the relative positional relationship of the image, it is possible to detect the amount and direction of focus
misalignment.
• Focus speed is determined instantaneously by using data gathered from the driving direction of the focus group.

75
Autofocus Two Types of Operation
− “FULL TIME AF” provides continuous autofocus operation allowing the camera operator to focus on framing the
subject.
− “PART TIME AF” allows for temporary autofocus use with manual focus. The modes can be switched on and off
as needed, using the ACTIVE/HOLD switch.
Size and position of the
AF frame (target area) in
the camera viewfinder
can be changed from the
Focus Demand.

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Minimum Object Distance (MOD)
− The minimum object distance (MOD) is the closest distance to witch the subject can be approached,
,measured from the vertex of the lens (the front most surface of the focusing group).
− Telephoto zoom lenses do not have as short an MOD as studio lenses. One reason for this involves the
structure of the focusing group. A telephoto zoom lens is focused by shifting the entire focusing group.
− If the length of shift is large, the focusing lenses have to be large to avoid cutting off light rays at wide
angle side.
TV Lens Focusing System
Length of Shift
Length of Shift
Focusing Group Focusing Group Fixed Group
MOD
MOD

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− In a wide angle studio lens, the focusing group is divided into a divergent subgroup and a convergent
subgroup, and only the divergent subgroup is shifted to focus the lens.
− This divergent lens focusing scheme can give a shorter MOD. It has other advantages as well: it reduces
the aberrations produced by shifting the focusing group, and it reduces the degree to witch focusing
changes the angle of view.
− If you need to get closer than the MOD, a micro feature, a close-up lens can be used.
TV Lens Focusing System
Length of Shift
Length of Shift
Focusing Group Focusing Group Fixed Group
MOD
MOD

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− In a Macro zoom lens, lens groups other than focusing group are shifted to focus on objects closer than
the MOD. As the object moves closer, the image point moves farther back from the lens. Macro shooting
with a zoom lens is possible if one of the lens groups can be moved to return the image point to the
normal image position.
− Besides the focusing group, several lens groups
can be shifted for macro focusing, such as the
relay group, variator or compensator.
− In figure the front relay group is shifted for the
macro effect. If the lens does not have macro
focusing but does have a flange-back
adjustment, a similar effect can be achieved by
using the flange-back adjustment. Flange-back
readjustment is then required when the lens
returns from macro to normal shooting, however.

– A television camera contains a beam splitting prism, filters, and other glass blocks.
– Its lens has to be corrected so that it will deliver optimum performance when these glass blocks are inserted.
– Different television cameras have different beam-splitting prisms, so the lens glass compensation has to be
matched to the type of camera.
– Currently, most camera manufacturers have standardized their 2/3" prism compensation and design for
their entire line of 2/3" cameras.
• This allows for camera matching between the studio type and the hand held cameras and allows a
user to combine both types of cameras for a production.
Glass Compensation
79

– When the prism mounted behind the lens differs from the designed glass compensation, the main effects
are increased spherical aberration and longitudinal chromatic aberration.
– When the glass thickness differs over-correction of spherical aberration occurs at the entrance surface of
the glass blocks inserted in a convergent optical path, and under-correction of spherical aberration
occurs at the exit surface.
Glass Compensation
80
Correction of spherical aberration taking a glass block into account
– The further the rays are from the optical axis, the
greater is the spherical aberration, so the glass
block as a whole gives rise to an over-
correction.
– The lens is therefore designed to leave spherical
aberration under-corrected, to cancel out the
over-correction of the glass block.

Glass Compensation
81
– When the glass block thickness differs from the design value, this balanced is lost, spherical aberration
occurs, and the modulation transfer function (MTF) degrades at high frequencies.
– With an F1.6 lens, differences in the
compensation thickness of 2 to 3 mm
can be ignored, but as the F-number
becomes smaller, the miscompensation
effect becomes larger.
– With an F1.2 lens, the difference must be
kept within 1 mm.
– Since the miscompensation effect lenses
as the F-number increases, if the lens is
stopped down to F5.6 or above, the
effect almost completely disappears.

– When the glass material differs differences in the dispersion of the glass (the way its refractive index varies
with wavelength) upset the designed balance that compensates for longitudinal chromatic aberration.
– Since zooming does not affect the deviation, however, a practical fix can be applied by adjusting the
tracking of the image pick-up tube.
Glass Compensation
82
Longitudinal chromatic aberration caused by different glass material
– The high frequency MTF varies slightly in the blue and
red channels.
– If the glass differs only in refractive index, with no
difference in dispersion, the effect is nearly zero.

– The letters and numbers at the end of the lens designation indicate the glass compensation type.
– If the designation is J18×9B4, for example, the letter B indicates that the lens is glass-compensated, and
the number that follows indicates the type of compensation.
– Lenses with different glass compensations have the same zoom components, but different relay lenses to
match the glass compensation aberration.
Glass Compensation
83

84
Background of the Development of Internal Focusing Lens
− In designing a zoom lens, it is very important to reduce the change in aberration during focusing as well as
the change during zooming.
− Conventional TV camera zoom lenses adopted one of the two focusing methods, i.e. the front group
rotate-out system, and the system in which the front group is divided into convex and concave elements
with rotate-out applied to the concave elements.
− Further improvements in performance are required for the zoom lens as CCD cameras are widely used
and HDTV technologies progress.
− Canon has been researching the possibility of improving the performance through the use of internal
focusing with a view to putting the idea into practice.
Internal Focusing

85
What is Internal Focusing?
− Internal focusing for a TV zoom lens can be simply explained as the application of floating to the front
group of a zoom lens.
− If the front group are split into two or three subgroups and the inner sub-group is moved for focusing, the
front and rear spaces of the focusing group are changed.
− The difference of the influences of the two spaces on the aberration is used to compensate the change in
aberration during focusing.
− Internal focusing works only when the distribution of aberration between the fixed group and the focusing
group is appropriately designed.
Internal Focusing

86
Characteristics of the internal focusing system
− Improvement of optical performance
− Using squire hood is possible because front group ifs stationary consequently ghosting and flaring more
effectively will eliminate.
− Reduction of the weight of focusing group
− Because of stationary front group filters (like polarizing ,ND , cross filters,….) can work more effective.
− Optional accessories such as a wide converter or teleside converter attached to the barrel of he front
group do not influence the focusing operation.
Internal Focusing

87
− Some single-lens reflex camera lenses with fixed focal lengths
employ a focusing method called a floating system.
− The floating system is also called aberration correction mechanism
for a short object distance.
− And it provides high imaging performance from infinity distance to
the minimum object distance (M.O.D.) by changing some air
spaces between the elements to compensate the change in
aberration during focusing.
− When the air space between the lens elements is changed, the
aberrations are affected.
− But if the air space is changed over some particular range, it
becomes possible to mainly change only the spherical
aberration, or the curvature of field, etc.
Focusing System

88
− Using floating systems to the front group of a zoom lens which
stabilizes in the change in aberration during focusing by
• presenting air spaces between the lens elements
appropriately
• changing them in accordance with the movable amount of
the focusing groups
Focusing System

89
− The focus optical subsystem entails high responsibility for numerous optical performance parameters and
operational considerations. The lens maximum relative aperture is largely determined by the diameter of
this lens input optical grouping.
Floating Focusing System
− In addition, focus breathing (undesirable alteration to
the field angle as the focus control is actuated)
characteristics and aberration behavior are
associated with this optical subsystem.
– Overall lens size and weight are heavily proportional
to decisions made in the overall design of this system.
Central to the design is curtailing the size and weight
of the moving lens system.
– To help ensure UHD optical performance focus
fluctuations must be suppressed – and this was
accomplished by using two separate moving groups.
Fixed Group Focusing Group
Floating Group
The distance of movement of the
focusing group is different from that of
the floating group.

90
− The conventional wide-angle zoom lens used in the studio employed a focusing system in which the front
group were divided into concave and convex portions and the front-side concave elements were moved
out for focusing. This method required a strong mechanical structure because the largest and the heaviest
lens elements had to be moved.
Examples of the Internal Focusing System
Example of the internal focusing system
− In the internal focusing system developed by
Canon for a wide-angle zoom lens, the front
group are divided into one concave and two
convex groups, and the convex group in the
middle is moved for focusing.

91
− In this case, the focusing lens group is moved backward for a close object, which is contrary to the
conventional system.
− Using this method, it is possible to attain a wide-angle zoom lens which retained its size small.
Example of the internal focusing system
− On the other hand, for a telephoto lens, the front
group are divided into two groups, and the rear-
side convex group is moved out for focusing.
− By taking the aberration sharing between the
front fixed group and the moving focusing group
into consideration at the design stage, highly
stable performance is obtained like the floating
system mentioned above.

92
− The focusing mechanism of the internal focusing system is shown in Figure.
− A Helicoid screw in which the focusing elements are mounted is connected to the external focusing ring
by means of a driving pin, and rotation of the focusing ring moves the focusing elements back

– Most lenses in home video cameras now have an autofocusing (AF) function.
– Two systems of autofocusing are used in still cameras and home video cameras:
• System 1: the triangulation system
• System 2: the sharpness detection system
– The triangulation system 1 is an automatic form of the range finder.
• Two field lenses (base lens and reference lens) are placed a certain distance (base length) apart,
and the images formed by them are moved until they merge precisely.
• The distance to the subject is then determined from the angle between the axes of the two lenses.
– In system 2, the sharpness of the image formed by the lens at a fixed position is detected, and the lens is
adjusted to give the sharpest image.
93
Auto Focus

– In the zoom lenses used in television broadcast cameras, the permissible circle of confusion has to be
smaller than in home video cameras. Due to its limited base length, the usual triangulation system is
insufficiently accurate.
– Parallax also occurs when the optical system that measures the distance is on a different axis from the
actual taking lenses, and the two are aimed at different points. The closer the subject is, the greater the
parallax becomes.
– To satisfy the zoom lens requirements of the broadcasting industry, Canon developed a through-the-
lens/active autofocus (TTL-A2F) system.
– In the TTL-A2F system, an infrared beam is projected from inside the taking lens toward the target object,
and the returning reflected light is detected.
– This prototype system was demonstrated in the P18 x 16B broadcast zoom lens at the 1980 International
Broadcast Equipment Exhibition, Japan, and of the 1981 NAB Show, USA.
94
Auto Focus

Hints on Focusing
95
1. Focus at the telephoto end, then zoom toward wide-angle. If the lens is first focused on the wide-angle
side, then zoomed toward telephoto, focus may be lost, because telephoto focusing is more delicate
than wide-angle focusing.
• A slight deviation from focus that would be unnoticeable on the wide-angle side becomes
increasingly apparent as the lens is zoomed toward telephoto.
2. The focusing ring turns past the ∞ mark. If the focusing ring of an ordinary film camera is turned all the way
toward infinity, it will stop just at the ∞ mark, in which position it is focused on infinity.
• A telephoto lens with fluorite components, however, can be turned slightly past the mark. The
refractive index of fluorite changes with temperature more than the refractive index of glass, so if this
margin were not allowed, the lens could not be focused to infinity at low temperatures (air
temperatures below 0°C, for example).
• Television zoom lenses use fluorite lenses to correct chromatic aberration, so like telephoto lenses, they
can be turned past infinity.

– This is not strictly classified as a distortion. In the eyes of practitioners, however, it behaves as an image
distortion.
– Focus breathing refers to the phenomenon of the change in image size when operating the focus control.
– It is an unwanted alteration in picture angle of view that is a consequence of moving optical elements
during focusing (an undesired result of zooming).
– While traditionally accepted in ENG shooting, it can be totally unacceptable in high-end drama and movie
shooting.
– Focus Breathing: Change in angle of view as focus is adjusted (changing of object dimensions when
focusing).
96
Focus Breathing

Digital Extender
• An extender is a function used to increase the zoom
range of a camera.
• The digital Extender Provide an electronic process.
– Conventional optical extenders use optical means to
change the lens’s focal length and increase the zoom
range.
– For example, a lens with a 2×optical extender doubles
the focal lengths of all zoom positions between the
wide-angle and telephoto positions.
– For a zoom lens with a focal length of 9.3-930 mm, a
2×extender converts this to 18.6-1860 mm focal Length.
97

98
Optical Extender/Built-in Extender
− In optics an afocal system (a system without focus) is an optical system that produces no net
convergence or divergence of the beam, i.e. has an infinite effective focal length.
− A built-in extender can be thought of
as an adaption of the afocal converter.
− A large studio lens may have two or
three built-in extenders, giving the
cameraman versatile lens-work options.

− The biggest advantage of the digital extender is that sensitivity remains unchanged (since the amount of
light reaching the image sensor remains unchanged), while optical extenders, by their very nature,
decrease sensitivity.
• For example, a 2×Optical Extender decreases sensitivity by 1/4. This requires the operator to either open
the iris by two F-stops or to accept a darker picture.
• Digital extenders also offer huge savings in investment costs compared to optical extenders, which can
often be extremely expensive.
• In digital extender to enlarge an image by 2×(2×wide and 2×high), three quarters of the image data or
pixels must be created by electronic means. Since these created pixels do not represent the true image
content, this reduces the horizontal and vertical image resolutions by half. This effect, of course, is not seen
in optical extenders.
99
Comparison Between Digital Extender and Optical Extender

100
Image Stabilizer
USM – this abbreviation means the lens is equipped with Canon's top-end focusing motor, the ring-type
UltraSonic Motor. This is a fast, quiet and powerful autofocus motor that allows full-time manual focus override.

101
Image Stabilizer (Optical Stabilized Technology)
– OS-TECH features “The Optical Shift System” where a shift correction signal is generated to optically
compensate for vibration according to the amount of the movement detected.
– This system responds quickly and reduces the phenomenon to a minimum allowing for a natural looking
image.
– The conveniently located control allows the operator to switch the anti-vibration system on and off.

Using a Zoom Lens Correctly
− Flange back adjustment
− Registration examination
− White balance adjustment
− White shading adjustment
− Cleaning
102

104
Classification of Aberrations
– Aberrations are departures of the path
of electron beams from the path of the
ideal (Gaussian or paraxial) imaging.
– The term, "(five) Seidel aberrations," is
the generic name of the third-order
aberrations (third order with respect to
the product of α (angle between the
electron beam and optical axis) and r
(distance of the electron beam from
the optical axis)), which occurs for a
monochromatic but non-paraxial
electron beam.
– The spherical aberration is most
important for the objective lens.

– All lenses have optical aberrations.
– There are the famous monochromatic (independent of wavelength (Seidel Aberrations)) aberrations
known respectively as
• Astigmatism
• Coma
• Curvature of field
• Spherical aberration
• Distortion
– There are two additional aberrations that are both wavelength dependent:
• Lateral Chromatic Aberration
• Longitudinal Chromatic Aberration
Aberration
105

106
Seidel Aberrations (Achromatic Aberration)
Ray paths with each Seidel aberration are descried in the left side. Shapes of the
electron beam with each Seidel aberration (spherical aberration, coma, and
astigmatism) are descried in the right side. Distortions on the screen with each
Seidel aberration (curvature of field and distortion) are descried in the right side.

107
This dot pattern is intended to represent the
light input to a lens system—consisting of an
array of infinitely small point light sources that
will stimulate the lens focusing aberrations.
This shows spherical aberration (exaggerated
for visibility) at the lens output.
Illustrates (again in exaggerated magnitude) the
form taken by comatic flare.
Note the progressive center to edge
defocusing associated with curvature of field.
Showing an exaggerated case of lens astigmatism
Astigmatism, Coma, Curvature of field, Spherical Aberration

Distortion (Geometrical Distortion)
108
– One of the conditions for an ideal lens is that “the image of
the subject and the image formed by the lens are similar,”
and the deviation from this ideal where the straight lines are
bent is called distortion.
– The extended shape in the diagonal view angle direction (+) is
called pincushion distortion, and, conversely, the contracted
shape (-) is called barrel distortion.
– With an ultra wide-angle lens, rarely do both of these
distortions exist together.
– Although this seldom occurs in lenses where the lens
combination configuration is at the aperture boundary, it
occurs easily in configuration lenses.
– Magnification/Focal length different for different angles of
inclination.
Distortion concerns the
overall shape of the image.
Positive or Pincushion
Distortion
Negativeor Barrel
Distortion

109
– Typical zoom lenses tend to exhibit barrel distortion at the shortest focal lengths and pincushion distortion
at the longest focal lengths (the distortion characteristics change slightly during zooming), but in zoom
lenses that use an aspherical lens, the aspherical lens is effective at removing distortion, so the correction
is good.
– This difference is caused by the difference in refraction of the principal rays passing through the center of
the lens, so it cannot be improved no matter how much the aperture is stopped down.
• Pincushion Distortion at Tele-End
• Barrel Distortion at Wide-End

110
Distortion is a change in magnification as a
function of field of view
θ
Real Chief Ray
Paraxial
Chief Ray
Distortion
(Positive)
Height
𝒚′ = 𝒇′ tan𝜽
NoGeometricDistortion 40%GeometricDistortion

– Distortion is expressed as the percent of the ideal image height.
111
ഥ
𝒀: Ideal image height
𝒀: Image height of a principle ray on the image plain
𝑇𝑉 𝐷𝑖𝑠𝑡𝑜𝑟𝑡𝑖𝑜𝑛 % =
∆ℎ
ℎ
× 100
𝑇𝑉 𝐷𝑖𝑠𝑡𝑜𝑟𝑡𝑖𝑜𝑛 % =
𝑌 − ത
𝑌
ത
𝑌
× 100

Spherical Aberration
112
– This aberration exists to some degree in all lenses constructed entirely of spherical elements.
– Spherical aberration causes parallel light rays passing through the edge of a lens to converge at a focal
point closer to the lens than light rays passing through the center of the lens. (The amount of focal point
shift along the optical axis is called longitudinal spherical aberration.)
– The degree of spherical aberration tends to be larger in largeaperture lenses.
• This is the phenomenon where the focus is not concentrated on one
point on the light ray but rather is offset to the front or back.
• Occurrence of a halo–––The image becomes flare.

113
∗ Paraxial Focus
Where light infinitely close to the optical axis will come to focus
Transverse Spherical
Longitudinal Spherical
∗
− The parallel light rays passing through the edge of a lens to converge at a
focal point closer to the lens than light rays passing through the center of the
lens.

114
– A point image affected by spherical aberration is sharply formed by light rays near the optical axis but is
affected by flare from the peripheral light rays (this flare is also called halo, and its radius is called lateral
spherical aberration).
– As a result, spherical aberration affects the entire image area from the center to the edges, and produces
a soft, low-contrast image which looks as if covered with a thin veil.
NoSphericalAberration With SphericalAberration

– Spherical Aberration can be defined as the variation of focus with aperture.
– Rays parallel to the axis do not converge outer portions of the lens yield smaller focal length.
– It affects the sharpness & MTF.
117

118
– Correction of spherical aberration in spherical lenses is very difficult.
– Although commonly carried out by combining two lenses –– one convex and one concave –– based on
light rays with a certain height of incidence (distance from the optical axis), there is a limit to the degree
of correction possible using spherical lenses, so some aberration always remains.
• This remaining aberration can be largely eliminated by stopping down the diaphragm to cut the
amount of peripheral light.
• With large aperture lenses at full aperture, the only effective way to thoroughly compensate spherical
aberration is to use an aspherical lens element.

Coma, Comatic Aberration
119
– Coma, or comatic aberration, is a
phenomenon visible in the periphery of an
image produced by a lens which has
been corrected for spherical aberration,
and causes light rays entering the edge of
the lens at an angle to converge in the
form of a comet instead of the desired
point, hence the name.
– Point off the axis depicted as comet
shaped blob
– The comet shape is oriented radially with
the tail pointing either toward or away
from the center of the image.
Point of Best
Focus
Coma Tail
This is the phenomenon where the diagonal light rays do
not focus on one point on the image surface.

122
– The resulting blur near the edges of the image is called comatic flare.
– Coma, which can occur even in lenses which correctly reproduce a point as a point on the optical axis, is
caused by a difference in refraction between light rays from an off-axis point passing through the edge of
the lens and the principal light ray from the same point passing through the lens center.
– Coma increases as the angle of the principal ray increases, and causes a decrease in contrast near the
edges of the image.

123
– Coma can also cause blurred areas of an image to flare, resulting in an unpleasing effect.
– The elimination of both spherical aberration and coma for a subject at a certain shooting distance is
called aplanatism, and a lens corrected as such is called an aplanat.
– A certain degree of improvement is possible by stopping down the lens.
– Coma can be controlled by shifting the aperture stop and selectively adding elements
NoComa With Coma

– Coma can be defined as the variation of magnification with aperture
– The Central or Chief Ray usually defines the image height
– A Comatic Image occurs when the outer periphery of the lens produces
a higher or lower magnification than dictated by the Chief Ray
124
Chief Ray

Astigmatism
125
This is the phenomenon where there is no point image
– With a lens corrected for spherical and comatic
aberration, a subject point on the optical axis
will be correctly reproduced as a point in the
image, but an off-axis subject point will not
appear as a point in the image, but rather as an
ellipse or line.
– This type of aberration is called astigmatism.
– It is possible to observe this phenomenon near
the edges of the image by slightly shifting the
lens focus to a position where the subject point is
sharply imaged as a line oriented in a direction
radiating from the image center, and again to
another position.

Astigmatism
126
Stopping down the lens aperture and
thereby increasing the depth of focus
absorbs astigmatism to some extent, but
does not remove it completely. Resolving
power charts with concentric circles and
radial lines are used for testing astigmatism.

127
Y
X
YZ Rays
Focus Here
XZ Rays
Focus Here
Z
Astigmatism = Essentially A Cylindrical Departure of The
Wavefront From Its Ideal Spherical Shape
Astigmatism
– An astigmatic image results when light in one plane (YZ) is focused differently from light in another plane
(XZ)

Astigmatism
129
Different focal length for inclined rays
Off-axis
Object
Area of Best Focus
Tangential
Focus
Sagittal
Focus
Tangential Focus
Sagittal Focus
Best Focus
Outside Focus
Inside Focus

Curve of Field (Curvature of field)
130
– Curvature of field is the failure of a lens to focus a plane object as a plane image.
– This is the phenomenon where, when focusing on a flat surface, the image does not become flat, but
where the image is formed in a bowed shape to the inside of the bowl.
NoFieldCurvature With FieldCurvature
This is the phenomenon where a good image focus surface is bent.
𝐴
𝐵
𝐶
𝐴
𝐵
𝐶
𝐴′
𝐶′
𝐵′
𝐴′′
𝐶′′
𝐵′

131
– Therefore, when focusing on the center of the frame, the circumference is blurred, and conversely, when
focusing on the circumference, the center is blurred.
– This image bending is mainly changed using the astigmatism correction method, which creates an image
between a sagittal image and a meridional image, so the more the astigmatism is corrected, the smaller
the image becomes.
cv cv

132
– Because there is almost no corrective effect from stopping down the lens, various efforts are made during
designing, such as changing the shape of the single lenses of the lens configuration and selecting the
aperture position, but one of the requirements for correcting astigmatism and image bending at the same
time is Petzval’s condition (1843).
– In the absence of Astigmatism, the image is formed on a curved surface called the “Petzval” Surface.
– This condition is that the inverse of the product of the index of refraction for each of the single lenses of
the lens configuration and the focal distance added with the number of single lenses used in the lens
configuration must produce a sum of 0. This sum is called Petzval’s sum.
For a single element as shown above, the Petzval
Radius is approximately 1.5 times the focal
length. This is for glass of 1.5 refractive index

– Refraction also holds true for the lenses used in a video camera lens.
– If one color is in focus on the imager, other colors will be slightly out of focus.
– Less chromatic aberration provide sharper images and are generally more expensive.
Chromatic Aberration
134

135
− We have two kinds of aberration:
• “Axial chromatic aberration” or “Longitudinal chromatic aberration”
• “Lateral (transverse) chromatic aberration” or “Chromatic difference of magnification”.
(In the actual video image, this appears as color fringing around color borders)

136
“Axial chromatic aberration”
“Longitudinal chromatic aberration”
“Lateral (transverse) chromatic aberration”
“Chromatic difference of magnification”.

– The lateral chromatic aberration is the most difficult to contend with in optical design and is a
consequence of each wavelength of light having a different magnification.
– The image sensor in the camera can read this as misregistration between the various wavelengths which
can cause color fringing on image transitions, and when added to the monochromatic aberrations, this
constitutes what are collectively called the aggregate defocusing distortions that impair lens MTF –
especially ate the wider aperture settings.
138

− Minimize the blur and colored edges caused mainly by lens chromatic aberration.
Chromatic Aberration Correction
139

Both axial chromatic aberration and lateral chromatic aberration become more noticeable in lenses with
longer focal lengths .
→ This results in the deterioration of picture edges.
– Video camera lenses used today are designed with considerations to reduce such chromatic aberrations.
– This is achieved by combining a series of converging and diverging lenses with different refraction
characteristics.
– The use of crystalline substances such as fluorite (or Calcium Fluorite) is also an effective means of
reducing chromatic aberration.
140

– Extra-Low Dispersion (ED) Glass for reducing chromatic aberration
141

142
Fluorite · UD Glass · Hi-UD Glass
– Unlike conventional optical glass, Fluorite has remarkably low
dispersion properties.
– Realizing the effectiveness of Fluorite glass, Canon has put it to
practical use in many lenses, primarily in the anterior section of
zoom lenses to help correct telephoto chromatic aberration.
– Both UD glass (UD-Ultra Low Dispersion) and Hi-UD (Hi-UD High
Index Ultra Low Dispersion) glass have dispersion properties similar
to Fluorite and are effective for correcting chromatic aberration.
• Due to its high refractive characteristics, Hi-UD glass is
especially known for its spherical aberration correction.
• Used in the anterior and zooming sections of a lens, Hi-UD glass
is effective for controlling aberration fluctuation seen when
focusing and zooming.

– Using Multi-Group Zoom
System: to suppress aberrations
over the entire zoom range.
– By employing a multi-group
zoom structure, aberrations are
suppressed over the entire
zoom range from wide angle to
telephoto, realizing high image
quality.
143

– Using Aspherical Lens to suppress various aberrations such as distortion and spherical aberrations
144

– Longitudinal chromatic aberration changes of red and blue wavelengths (with respect to green) with
focal length in an HDTV zoom lens — error typically being greatest at telephoto setting.
Chromatic Aberration Measurement
145

– Shown here are lateral chromatic aberration changes with focal length in an HDTV studio zoom lens.
– This error is typically greatest at the wide-angle setting.
146

– Lateral chromatic aberration (exaggerated here for visibility) is measured at a specific image height of
3.3mm within the 2/3-inch 16:9 image format (HDTV Lens).
147

– The two circles are intended as a 0.6 percent reference to convey a sense of the magnitude of lateral
chromatic aberration in a contemporary HDTV studio lens.
– The actual red and blue aberrations are shown calculated.
148

– The creation of color fringing around a white-to-black followed by a black-to-white transition (in
exaggerated form for visibility).
149

Changing in Chromatic Aberration Caused by Zooming
150
Longitudinal Chromatic Aberration
• This aberration is largest at Tele-End.
• Corrected by fluorite or extraordinary
dispersion glass.
Lateral Chromatic Aberration
• The red and blue registration lines trend
across the green line as they move from
Wide-End to Tele-End.
Wide Angle Focal Length Telephoto
mm
Wide Angle Focal Length Telephoto
mm

151
Relationship Between Aperture and Aberration

− Horizontal resolution is used to indicate only the highest resolving ability.
− Horizontal resolution only defines the finest level of detail that is viewable
⇒ not clearly or sharply viewable
• Modulation depth is used to indicate how sharp or how clear an image is reproduced.
• For this reason, modulation depth focuses on the response of the frequency ranges that most effect the
image’s sharpness.
• It is the frequency response in practical frequency ranges that governs the camera’s sharpness – rather
than horizontal resolution.
Modulation Depth
152
33.5 cycles
per image width

− Frequency response is usually measured by shooting a Multi Burst chart, which has vertical black and
white lines with different spatial frequencies. For measuring modulation depth:
• In SD camera, usually the 5 MHz area is used.
• In HD video cameras, the 27.5 MHz area is used.
− The closer the response is to 100% at 5 MHz (SD), the higher the capability to reproduce clear and sharp
picture details.
Modulation depth can be influenced by the performance of the camera lens and thus
measurements should be conducted with an appropriate lens.
Modulation Depth
153

Modulation Depth
Plumbicon Lamps
154
• Shading correction: ON
• Aperture correction: OFF
• Gamma correction: OFF
• Contour correction: OFF
• Colour correction: OFF
• Iris: F/5.6 for 2/3 '' CCD, F/4 for 1/2 '' CCD

Lens Contrast Ratio (Optical Contrast Ratio)
156
– Lens contrast ratio is the ratio of the percentage of 100% input white light that reaches the lens output to
the residual unwanted light level when imaging a true black (0% input black) in the scene.
100%
0%
White Reproduction
Black Reproduction
Lens Output
Light Level
Lens
Contrast
Ratio
100%
0%
Test Chart

157
– Cinematographers often speak of the “clarity” and “brilliance” of a specific lens and in so doing they are
largely referring to the optical contrast performance of that lens.
– The Contrast Ratio of a lens is a formal definition of that performance. I
• It is the ratio of the level of transmissivity through the optical system to the level of optical black
contamination on the output caused by flare and veiling glare.
– It is sometimes likened to an optical “signal to noise”.
Lens Contrast Ratio
100%
0%
White Reproduction
Black Reproduction
Lens Output
Light Level
Lens
Contr
ast
Ratio
100%
0%
Test Chart

– Lens Contrast Ratio is the ratio of the level of transmissivity through the optical system to the level of optical
black contamination on the output caused by flare and veiling glare.
– Contrast Ratio defines the “brilliance” of an image.
– The behavior of that contrast ratio with increasing spatial detail defines the perceived picture sharpness.
Lens Contrast Ratio
158
Contrast Ratio

A lens with no coatings A lens with coatings
“Vividness”
“Brilliance”
“Clarity”
Transparent Metallic
Compounds
•SiO2 (quartz)
•Magnesium Fluoride (MgF2)
•Hafnium Oxide HfO2
•Titanium Dioxide TiO2
•Zirconium Oxide
Lens Contrast Ratio
159
Cinematographers have
their own descriptive
language to comment on
the subjective
appearance of lenses
having high Contras
ratios:
• “Vividness”
• “Brilliance”
• “Clarity”

Lens Contrast Ratio
160
Dual benefits of optical coatings on each and every lens element
Transmittance (%)
Wave length (nm)
Anti-reflective coatings on all lens element
surfaces defeats the reflections at each -thus
elevating overall light transmission
By reducing the many reflections the lens coatings also
significantly attenuate associated light scatter-thus
reducing lens flare and veiling glare
Lens Element Coatings increase Lens Contrast Ratio
– Use of Multilayer Anti-Reflection Coatings
• Raise Light Transmittance
• Lower Black Optical Contamination

Coating Effect
161
– If the refractive index of glass is 𝑛𝐺, at the
interface between glass and air,
orthogonally incident light will be reflected
with a reflectance of:
– It follows that 4% to 10% reflection occurs
at each lens surface.
– In zoom lens, which has many lens
surfaces, this can amount to a
considerable loss.
– Multiple reflections within the lens system
can also cause flares and ghost images.
– To reduce troublesome reflections, lens
surfaces are given special coatings.
𝑟 =
𝑛𝐺 − 1
𝑛𝐺 + 1
2

162
– The secret to elevating lens contrast lie in the deep sciences of
multilayer optical coatings that are deposited on each and
every lens element surface.
• When a lens that does NOT employ such coatings images a
black and white chart the level of transmitted white light
through the optical system incurs a loss in transmissivity due
to reflections at each and every air‐glass surface
(approximately 4% for each uncoated surface).
• These same reflections cause a light scattering within the
overall optical system – creating flare and veiling glare that
contaminates what should be zero light transmission for the
black portion of the chart.
Lens Contrast Ratio

Lens Contrast Ratio
163
− Showing an optical system of eight uncoated lens elements and the progressive 8% light loss per element
due to reflections at each surface – which in turn creates light scatter that causes flare and veiling glare.
Reflected light creates
multiple additional reflections
known as Light Scatter.
Total reflection Loss= 8%
Incident Light

164
For an uncoated lens element there is approximately a 4% loss of light
transmission at each air-glass surface
Lens Contrast Ratio
100% 92%

165
Lens Contrast Ratio
100% 92% 85% 78% 72% 66% 61% 56% 52%
Light passing through eight uncoated lens elements will incur
an almost 50% loss in light transmission
SIGNAL
“NOISE”
The light reflections at each surface travel back through the lens and
cause flare on black portions of the image

166
– The deposition of the multilayer coating creates
secondary reflections that cancels the primary
reflection – thus elevating light transmission
through the optical system, and at the same
time lowering the light scatter so that a superior
black reproduction is simultaneously made
possible.
– Multilayer coatings of different materials on
each surface are required to manage all of the
wavelengths across the visible color band.
Lens Contrast Ratio

High Transmittance Electron Beam Coating (HT-EBC)
– High Transmittance Electron Beam Coating (HT-EBC) for decreasing flare and ghost
– Adopting HT-EBC coating technology that achieves a low 0.2% reflection or less over a wide spectrum of
wavelengths keeps surface reflection of the lens to the absolute minimum and makes it possible to render
truer “blacks”.
167

High Transmittance Electron Beam Coating (HT-EBC)
168
– High Transmittance Electron Beam Coating (HT-EBC) for decreasing flare and ghost.
– In addition, camera adjustment is easier because the transmittance balance is improved from the shortest
to the longest visible wavelengths.

Development of New Barrel Design
169
– Optimizing the shape of the lens barrel interior as well as its surface treatment effectively suppresses
ghosting and flares.

170
– Development of new polishing techniques and improvements in measurement precision achieve surface
accuracy more than three times higher than that of HD, contributing to higher image quality.
High Surface Accuracy (Polishing)

171
Lens MTF (Modulation Transfer Function) or Contrast Transfer Function (CTF)
– MTF is a representation of the behavior
of the contrast level of increasingly
higher spatial frequencies as they pass
through an imaging system.

172
– MTF is a powerful and practical tool for assessing the resolution behavior of individual components of a
total imaging system (such as a lens, a camera, a display, a printer etc).
– MTF allows an assessment of the overall resolution of that total system – which, is after all, what ultimately
impacts our human visual system.
– Consider a lens imaging a very low frequency set of adjacent black and white bars.
• As the lens transmits the light from that scene object there will be a modest loss of the white and there
will be an elevation of the black (due to internal flare phenomenon).
• Thus, the output optical reproduction of the black and white scene will incur a small loss of contrast –
and the formal Contrast Ratio of that lens will then be as defined in Figure.
Lens

173
– As the spatial frequency of the black and white bars being imaged by the lens is increased the contrast of
their optical reproduction at the lens output lowers. The higher that spatial detail becomes the lower its
contrast at the lens output port.
• There is a modulation of the transfer of contrast through the lens as a function of spatial frequency.
Modulation Transfer Function is the ratio of the contrast in the Scene Object to
the contrast in the Object Image as a function of spatial frequency.
Lens

Lens MTF (Modulation Transfer Function)
– Indicates a lens’s ability to reproduce the contrast of picture details.
– Since the human eye is more sensitive to changes in brightness than to color, MTF is defined as a lens’s
capability to reproduce detailed brightness (or luminance) changes.
174
Scene Test Chart
Spatial Frequency in Line pairs / mm
100%
0%
White Reproduction
Black Reproduction
Lens Contrast Ratio 𝑪 =
𝑴𝒂𝒙 – 𝑴𝒊𝒏
𝑴𝒂𝒙 + 𝑴𝒊𝒏
Lens Contrast Ratio

175
Scene Test Chart
100%
0%
White Reproduction
Black Reproduction
Lens Contrast Ratio
Lens Contrast Ratio

176
Scene Test Chart
100%
0%
White Reproduction
Black Reproduction
Lens Contrast Ratio
Lens Contrast Ratio

177
Modulation of the Transfer of Contrast
with increasing Spatial Detail
Band-edge of interest
for a given Imaging system
Lens
Contrast
Ratio
– Showing a representative falloff in lens contrast – spanning very low spatial detail to the highest spatial
detail that defines the pass band of interest for a given imaging system.
– The spatial frequency at which the MTF has dropped to a level below 10% is referred to as the Limiting
Resolution or the Resolving Power of the lens.
100%
0%
White Reproduction
Black Reproduction
Lens Contrast Ratio
Lens Contrast Ratio

178
Low Frequency High Frequency
Scene Object Scene Image
Black
100%
Contrast
White
Line Pair
Imaging Lens Imaging Lens
Image Object
Image Object
Black
100%
Contrast
White
Modulation Transfer
Function is the ratio of
the contrast in the
Scene Object to the
contrast in the Object
Image as a function of
spatial frequency.

179
Modulation Transfer
Function is the ratio of
the contrast in the
Scene Object to the
contrast in the Object
Image as a function of
spatial frequency.
Black
90%
Contrast
White
MTF
Black
20%
Contrast
White
Frequency in LP/mm
Modulation
Image Object
Image Object

180
https://www.olympus-lifescience.com/ja/microscope-resource/primer/java/mtf/spatialvariation/

Example:
− Lens B is capable of resolving the image at
higher spatial frequencies (detailed areas of
the image) and may often be mistaken as
having more resolving power than Lens A.
− However, up to point X, Lens A has higher
resolving power, which contributes more to
reproducing the image with higher contrast.
− When choosing a lens, both its MTF curve and
maximum resolving power must be considered
with care.
181

– Contrast is the ratio of the amplitude of the sine-wave, A, to its
average value, B.
– Since, 𝐴 = (𝑀𝑎𝑥 – 𝑀𝑖𝑛) / 2 and 𝐵 = (𝑀𝑎𝑥 + 𝑀𝑖𝑛) /2
– Note that C must lie in the range 0 to 1.
• If the contrast is 1 the centres of the black lines are completely black.
• If the contrast is 0 the target is uniformly grey.
– Figure shows a graph of the variation of intensity in a sine-wave target with distance. The target is
characterised by its Spatial Frequency and Contrast.
– Spatial Frequency (u) is the number of cycles (or line-pairs) per millimetre, and is given by u = 1 / P where P
is the period of the wave in millimetres.
182
Exact Definition of Contrast of an Imaging System
𝑪 =
𝑴𝒂𝒙 – 𝑴𝒊𝒏
𝑴𝒂𝒙 + 𝑴𝒊𝒏
𝑪 =
𝑨
𝑩
Lens

– The MTF, or Modulation Transfer Function, is defined as the ratio of the image contrast to the target contrast,
expressed as a function of spatial frequency. That is,
183
Exact Definition of MTF of an Imaging System
𝑪 is the contrast in the target
𝑪’ is the corresponding contrast in the image
– For low spatial frequencies the MTF is nearly 1.0 or 100%.
– The curve then generally falls as spatial frequency increases, until it reaches zero, the limit-of-resolution
for the lens.
– Test patterns of this frequency and above are imaged with zero contrast, that is, as a patch of uniformly
grey light.
𝑴𝑻𝑭(𝒖) =
𝑪’(𝒖)
𝑪(𝒖).
𝑢

184
Spatial Frequency
• For HD lens depth of field is smaller therefore focusing has to be done with more care.
• Large aperture lenses with small F-number are used.

185
Nyquist Frequency for HD and 4K-UHD Lenses
2/3 inch HD 2/3 inch 4K
Image Size 9.6mm × 5.4mm 9.6mm x5.4 mm
Effective Pixels 1920 × 1080 3840 x 2160
Pixel Size 5𝛍m × 5𝛍m 2.5𝛍m × 2.5𝛍m
Nyquist Frequency
100 Ip/mm
1080 TVL
200 lp/mm
2160 TVL

4K Lens Criteria – Optical Nyquist Spatial Frequency is 200 LP/mm
− We have defined the optical Nyquist frequency for a 4K 2/3 inches lens.
− It means that this lens needs to be able to pass through its entire optical system 200 black and white lines
(line pairs) within every millimeter of the image size.
− Consider what it takes to pass that through every horizontal (and vertical) millimeter of the lens output
image—and to do so with as high a contrast as possible.
186
4K UHD Optical Nyquist Spatial Frequency
One
Millimeter

187
4K UHD Optical Nyquist Spatial Frequency

188
Importance of the Half Nyquist Frequency
– The accumulated subjective experience around the world has shown that what we actually see on the
large screen (television or theater) – what is termed Perceived Picture Sharpness – is directly related to the
level of contrast at HALF of the Nyquist frequency than at the Nyquist limit itself.
For the 4K lens our optical
designers focus on
elevating the MTF at 100
LP/mm as high as possible.
A really good 4K lens will have a contrast
greater than 80% at 100 LP/mm
The center of the passband (100 LP/mm) is the most important
region in the term of 4K perceived picture sharpness.
1080 TVL/ph
(100 LP/mm)
2160 TVL/ph
(200 LP/mm)
Video Spatial Frequency
(Optical Spatial Frequency)
4K Nyquist
HD Nyquist
Critical Portion of the
4K Lens-Camera MTF Curve
4K Half Nyquist

189
Effective MTF of the Lens‐camera Imaging System
– The lens optical MTF is multiplied by the camera electronic MTF (largely determined by the sampling
mechanism of the image sensor and its associated optical low pass filter) to produce the effective MTF of
the lens‐camera imaging system.
70
60
50
40
30
20
10
0
80
90
100
0 50 250
MTF(%)
100 150
Spatial Frequency(lp/mm)
Camera MTF
Lens MTF ref. (F/2.8 diffraction limit)
Lens MTF ref. ×Camera MTF
200
4K Nyquist
2/3-inch Lens MTF at PictureCenter

190
– The lens optical MTF is multiplied by the camera electronic MTF (largely determined by the sampling
mechanism of the image sensor and its associated optical low pass filter) to produce the effective MTF of
the lens‐camera imaging system.

191
– That overall MTF curve greatly affects the faithfulness of the video representation of the scene being
imaged.
• The higher that composite MTF curve is around the half Nyquist spatial frequency (1080 TVL/ph in
video terms and 100 LP/mm in optical terms), the sharper the most important elements of an image
will appear to the viewer.
• Edge sharpness is critically important to close‐ups and to very wide‐angle scenes.
• Textural reproduction (facial, hair, clothing, materials etc) is also a key element in high‐resolution
reproductions.

192
100 %
4K Nyquist
Human Visual Contrast
Sensitivity Curve
Very
Fine
Detail
1080 TVL/ph
(100 LP/mm)
2160 TVL/ph
(200 LP/mm)
Half Nyquist
Textural
Reproduction
Picture
Edge
Sharpness
MTF
MTF and Perceived Sharpness
Lens-Camera MTF Curve

193
Lens # 2
Contrast Ratio
Lens #1
Contrast Ratio
Clearly, a lens having a higher contrast ratio
is likely to have a higher MTF
0%
White
Reproduction
Black
Reproduction
Lens Contrast
Ratio
100%
MTF and Perceived Sharpness

194
100 %
Human Visual Contrast
Sensitivity Curve
Very
Fine
Detail
Textural
Reproduction
Picture
Edge
Sharpness
MTF
4K Super 35mm lens MTF and Perceived Sharpness
4K Super 35mm lens
Lens-Camera MTF Curve
4K Nyquist
Half Nyquist
1080 TVL/ph
(40 LP/mm)
2160 TVL/ph
(80 LP/mm)

Resolution Across the Image Plane
– It is a fundamental optical behavior that MTF will fall off from its peak at picture center toward the image
extremities.
– This has long posed a challenge to optical designers. It is an important quest because our human
perception of picture sharpness assimilates the resolution of the image across the total image plane.
• This acquires an even higher importance with the superb picture sharpness of the 4K imaging system –
especially on a large cinema screen.
195

– Recognizing the impossibility of achieving a totally constant MTF across the image plane, the optical
designers define two circular zones – based upon years of collaborative experiences with
cinematographers – where they make every attempt to maintain close to constant MTF.
– What really defines the high-performance 4K lens is how that resolution is managed across the entire
image plane.
196
Outer Zone or Corner Zone

– Recognizing the impossibility of achieving a totally constant MTF across the image plane, the optical
designers define two circular zones – based upon years of collaborative experiences with
cinematographers – where they make every attempt to maintain close to constant MTF.
197
Outer Middle Cente Middle Outer
– These spatial zones are related to the
interest of cinematographers who seek a
constant sharpness across the most
important middle zone that typically will
encompass a facial close‐up or a medium
close‐up.
– The outer zone encompasses the greater
portion of a wide angle scene –and here
there will be a well‐controlled roll‐off of MTF
at the outer portions.

198
Outer Middle Center Middle Outer
Typically will encompass a facial close‐up or a medium
close‐up. Cinematographers who seek a constant
sharpness across the most important middle zone
The outer zone encompasses the greater portion of a wide angle scene –and
here there will be a well‐controlled roll‐off of MTF at the outer portions.

199
100%
Outer Middle Center Middle Outer
MTF
The primary design goal is to get the MTF
as flat as possible across the inner zone

200
Showing the two zones traditionally used by Canon
to specify levels of MTF across the lens image plane
and the idealistic design goal of seeking as flat an
MTF as possible across the middle zone

Large-Aperture Aspherical Lens
– Using a high-precision large-aperture aspherical lens element ensures high MTF to the very edges of the
image.
201

– The challenge of tightly controlling lens MT of is further complicated in
zoom lenses – because it is also an optical reality that MTF changes
over the focal range of the zoom lens.
– And again, the optical designers mobilize further innovative optical
design strategies to minimize these changes.
– The demands on 4K lens design are higher than that of HDTV lenses –
because of the anticipated very high bar in image resolution. It is
customary to show the variations in MTF across the image plane and its
variations with focal range in one chart.
202
Maintaining 4K Resolution over the Total Focal Range

– It is not over yet! It is also an optical fundamental that the distance of the scene object to the lens front face
also affects the MTF behavior of the lens.
– But, this too can be controlled to a degree with strategic optical design.
– The imperative to do so is that much greater in a 4K lens than in an HD lens because of the anticipated
broad use for theatrical motion pictures.
– On those very large screens a rack focus between two subjects at different depths within a given scene that
entails a change in image sharpness is likely to be seen more readily than on a 50 or 60‐inch HD home
viewing display.
203
Variation of MTF with Object Distance

204
Areas where Improvements are being Implemented
Lens MTF varies with each of the following:
• Radial distance from Image Center
• Focal length
• Aperture Setting
• Subject Distance from lens front

– Optical system where the performance does not improve, no matter how much the aberration is reduced.
This is called the diffraction limit.
– There is a residual aberration in a general zoom lens or a camera lens.
– So the blurring caused by the aberration is larger than that caused by diffraction when the F-number is
small.
– The lens is nearly being free of aberration when it is stopped down until the F-number is about 5.6. If the
lens is stopped down further, however, the MTF is not increased, but is lowered.
– In an HDTV lens, the influence of diffraction cannot be ignored because the evaluation frequency is high.
When using a HDTV camera, care must be taken not to stop down the lens too much, and for this reason,
ND filter or suchlike is attached to the lens or camera.
Diffraction Limit
207

208
Lens Personality
− The “personality” of a given lens is bound up in the accumulated imaging attributes of that optical system
that is further tempered by the residual aberrations and artifacts
Lens Personality
“Look” & “Feel”
Contrast
Optical
Speed
MTF
and
Sharpness
MTF Disposition
over Image
plane
Depth of Field
Color
Reproduction
Skin Tone
Reproduction
Relative Light
Distribution
Geometrical
Distortion
Depth
Perspectives
Chromatic
Aberration
Monochromatic
Aberration
Focus
Breathing
Bokeh
Optical Design

209
Optical Design Parameters
Optical Design Parameters Video Imaging Attributes
1. Max Aperture
2. Image MTF (at picture center)
3. Image MTF (at picture corners)
4. Contrast Ratio
5. Chromatic Aberration
6. Monochromatic Aberrations
7. Relative Light Distribution (evenness of brightness across image plane)
8. Black Reproduction
9. Spectral Transmittance
10. Handling of strong highlights
11. Geometric Distortion

210
Large Studio Box Lens, EFP/ENG Lens

211

212
Very High
Very High
High
Very Good
Superb
Exceptionally High
Tightly Controlled
Tightly Controlled
Very small
Almost zero
High
High
Reasonably high
Reasonable
Very Good
High
Controlled
Controlled
Reasonable
High (ENG lens)
Moderate ( EFP lens)
1. Sensitivity (max lens aperture to provide more light)
2. Image Sharpness (at picture center)
3. Image Sharpness (at picture corners)
4. Relative Light (evenness of brightness across image plane)
5. Black Reproduction
6. Contrast Ratio
7. Chromatic Aberration
8. Monochromatic Aberrations
9. Geometric Distortion
10. Focus Breathing (Change in angle of view as focus is adjusted)
Picture Performance Attributes HDTV
Studio Lens
HDTV
EFP/ENG Lens

– To temporarily zoom to a telephoto position simply by pressing and holding a switch.
213
Quick Zoom Function

– To limit the zoom position to a point before F-drop begins.
– Making it possible to reduce the workload during video production.
214
F-Number Hold

– The zoom and focus can be preset at a selected position and stored in advance.
215
One Shot Preset

– Three different curve for each of zoom and focus (like as sample lens).
216
Zoom/Focus Mode selection Function

– Focus Breathing: Change in angle of view as focus is adjusted (changing of object dimensions when
focusing).
– This compensation mechanism synchronizes zoom movement with the focus movement to automatically
correct for changes in the angle of view, thereby minimizing breathing and keeping the image size
constant.
– This function eliminates the need to reset the angle of view after focusing, providing a high level of
operability.
217
Automatic Compensation of Focus Breathing

– Pressing the C-Z button while zooming will set the zoom speed at that rate.
– Slightly pressing the seesaw switch a second time will return the zoom speed to normal.
218
Auto Cruising Zoom

– By adopting nine iris blades. 4K lens achieves a nearly circular aperture.
– This makes it possible to render images taking full advantages of the softer, more natural bokeh.
219
Natural Bokeh with at Least Nine Iris Blades

– You can “shuttle” between any two zoom positions as you like.
– At the touch of a button, this feature allows the operator to zoom back and forth instantly between any two
positions at the maximum speed or at any speed memorized in the Speed Presets.
– It can be used for zooming to either the tele-side or wider focal length from any starting point to check the
picture, and then return instantly to the original focal length.
220
Shuttle Shot

– Between any two points in the highest speed , zoom position can make a round trip like a shuttle by pushing
a simple button.
– In case the preset position is set at tele-end, it works exactly the same as Quick Zoom.
– In other words, Fujinon Fujinon Q.Z. can only be used as just a tool for focusing.
= Not for actual shooting.
221
Shuttle Shot
(Push) (Release)
Shuttle
ON
Shuttle
OFF
The highest speed The highest speed
A shot frame Preset shot frame Goes back to the original frame
= total shot = bust shot = total shot

– A zoom speed agreed on during rehearsal can be reproduced accurately.
– The preset memory is not automatically cleared and can be repeated as many times as needed.
– Simply press a button to recall the preset zoom speed.
222
Speed Preset

– Zooming speed can be preset in memory and is possible to repeat by pushing a simple button.
– Example 1: Candidates election broadcast on TV (stating their political opinion)
• Reqiers the same zooming speed for each candidate
– Example 2: A rehearsal & Going on the air
• A zoom speed can be preset during a rehearsal, and the zoom speed can be repeated during the
performance.
223
Speed Preset
15 sec
later
30 sec
later
Speed
ON
Steady Speed Steady Speed
• Speed preset works exactly the same as Auto Cruise , in case it is not necessary to repeat the zoom speed.
• In other words, Fujinon Auto Cruise can not be used for both of the said examples , since it can be used only once and impossible to repeat.

– With the Frame Preset feature, a preset frame position can be saved and repeated multiple times.
• A movement to a preset position can be repeated multiple times.
– The preset memory is not automatically cleared and the agreed-on framings from rehearsal can be
duplicated over and over in an actual production at the maximum speed or at any desired speed
memorized in the speed preset function.
224
Frame Preset

– Angle of view can be preset in memory, and move to the position in the highet speed by pushing a simple
button.
– Example: Restore the zoom position during the performance which was preset at the rehearsal
– Easy to repeat the same zoom position always in the highest speed.
225
Frame Preset
Frame
ON
The highest speed
A Shot Frame A Preset Shot Frame

– Angle of view can be preset in memory, and move to the position in the highet speed by pushing a simple
button.
– By combination of Speed preset and Framing preset, a preset shot frame can be used as a starting position
of Speed preset.
226
Frame Preset
Frame
ON
Speed
ON
Steady Zooming
The preset zoom speed
The highest speed
A Shot Frame A Preset Shot Frame

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