Broadcast Lens Technology Part 3

Dr. Mohieddin Moradi
mohieddinmoradi@gmail.com
Dream
Idea
Plan
Implementation
1

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
3

6
4K Premium Lens Specifications
Optical
Performance
Operational
Specification
Physical and
Ergonomic
Specifications
New
Long Zoom
Field Lenses
• Sharpness
• Chromatic Aberration
• More telephoto
• Wider FOV
• Enhanced Image Stabilizer
• New Creative Effect
• HDR
• WCG
• New Styling
• Modest Size
• Modest Weight

– Because the 4K image sensor can see four times more spatial detail than an HD image sensor it becomes
imperative to more tightly control optical aberrations in a 4K lens –and most especially to curtail, to the
degree possible, the lateral chromatic aberration.
– The quest to enhance the overall MTF characteristics of the 2/3-inch 4K UHD lens inherently entailed further
minimization of the various optical aberrations (four monochromatic and two chromatic) as they
collectively are termed the defocusing distortion that impose another boundary to image sharpness.
– Separately, high attention was paid to curtailing both the longitudinal and the lateral chromatic
aberrations as the higher resolution of the 4K camera allows even a small degree of color fringing to be
more visible.
Chromatic Aberration in UHD Lens
7

– If enough optical strategies are mobilized (number of lens elements increased, adroit combinations of
different glass materials deployed, selective shaping of the individual lens elements, and selective use of
aspheric lens elements) then this red curve can be driven to the left which opens up the range of aperture
stops that can deliver the full 200 LP/mm and more.
– These strategies do not come cheaply, which is one reason that high performance 4K lenses are not
inexpensive. In 4K lens design – you really do get what you pay for.
8
Chromatic Aberration in UHD Lens
The black curve labelled diffraction
limited – is a fixed curve for all lenses of
a given image format size.
No optical design ingenuity can
counteract that limitation which imposes
a progressive lowering of MTF as the lens
aperture is stopped down.
The red curve on the left –
the aggregate of all of the
lens aberrations is, to quite
a degree, under control of
the optical designer.
Desired Resolution=200 LP/mm

9
Resolving Power/Resolution
– The resolution of a lens indicates the capacity of reproduction of a subject point of the lens.
– The resolution of the final photograph depends on three factors:
• the resolution of the lens
• the resolution of the film or image sensor
• the resolution of the printer or printing paper
– It is common to hear resolution expressed as a numerical value such as 50 lines or 100 lines. This value
indicates the number of lines per millimeter of the smallest black and white line pattern which can be clearly
recorded on the film. To test the resolution of a lens alone, a method is used in which a fine resolution chart is
positioned in the location corresponding to the focal plane and projected through the test lens onto a
screen.
– The numerical value used for expressing resolving power is only an indication of the degree of resolution
possible, and does not indicate resolution clarity or contrast.

10
Resolving Power/Resolution
– “The ability to project very fine detail through the lens”
– High resolving power is required to take full advantage of a 4K camera
– Achieving High Resolving Power is achieved by:
• Sophisticated optical design
• Premium glass material
• Cutting edge manufacturing & polishing process
• Highly precise and alignment and assembly

11
Resolving Power/Resolution Measurement Charts

12
The Importance of an Excellent Contrast Ratio In a 4K Lens
– High emphasis is placed on the importance of an excellent contrast ratio in a 4K lens for two important
reasons:
• A high contrast lens will greatly contribute to a lens‐camera capture system being able to portray vivid
reproduction of scenes containing both bright and dark sections
• Perceived picture sharpness on a large screen viewed from typical viewing distances is directly
influenced by an established method of measuring the resolution behavior of lenses, cameras, and
displays –namely, the Modulation Transfer Function (MTF) of each of those systems.

13
Resolving Power/Resolution (High Frequency) + Contrast (Low Frequency)
Critical Linkage between Resolving Power/Resolution and Contrast

14
Low Frequency
Center
Low Frequency
80%S
High Contrast Resolution
HD
HD
HD
Center
S
T
Low Frequency
80%T
High Frequency
80%T
High Frequency
80%S
High Frequency
Canter
4K Lens enables to reach higher resolution and contrast.

15
HD quality
Center
Corner
Center
Corner
HD
Freq.
4K
Freq.
Freq. (lp/mm) Freq. (lp/mm)
HD
Freq.
4K
Freq.
Resolution and Contrast
4K Lens enables to reach higher resolution and contrast

16
Large Studio Box Lens, EFP/ENG Lens
− Simplistic mapping of the performance levels within the separate categories of box lenses and portable
lenses.

17
4K Lens Critical Performance Parameter
HDR
Sharpness
Color Gamut
Longitudinal
Chromatic
aberration
Lateral
Chromatic
aberration

18
Benefit of 4K Lens for WCG and HDR

19
36
SDR
HDR
Crushed
shadow
Gradation
in shadow
4K
HD 4K
There is no difference
Big difference
HD
Easy to see the resolution power
in dark & bright area

20
SDR
Almost same amount of
purple fringe
Purple fringe is more obvious on HD lens
because amplified brightness
HDR
*Captured by iPhone
HD 4K
HD 4K

21
HD Lens
4K Lens
W/O correction With Correction
Less colorfringe W/O correction With Correction
Chromatic aberration correction (ex. ALAC) corrects
the position of each color, but fringe phenomenon is
from blue color shown on circled in red

22
HD
4K
Newly designed barrel
• Cut off unnecessary light
ray by new designed
barrel and its lens cell,
then it reduces Flare.
• 4K lens can cut the flare and reduce black floating
even in a backlit conditions.
• Black floating is more noticeable in HDR. Black Level Difference

23
Black level of
HD: 14.7% Full
4K:12.4%
HD lens (XA99x) 4K lens (UA80x)
– Compare black level between HD lens and 4K lens.
– Black level of HD lens is 14.7%, while 12.4% for 4K lens.

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– Compare black level between HD lens and 4K lens.
– Black level of HD lens is 21.9%, while 11.6% for 4K lens.
• 4K lens can cut the flare and
reduce black floating even in a
backlit conditions.
• Black floating is more
noticeable in HDR.
• Same object and same white
level, but black level of
• HD: 21.9% (HD lens reduces
dynamic range!)
• Full 4K:11.6%
Same object and same white level,
but black level of
HD: 21.9% Full
4K:11.6%
HD lens reduces dynamic range!
HD lens (HA23x) 4K lens (UA22x)

25
0
20
40
60
80
100
350 450 550 650 750
HD
4K
Coverage of
Lens
– Both HD and 4K lens covers BT.2020.
– Improve the transparency of Blue in 4K lens. Better S/N ratio.

26
4K/UHD Lens
https://www.youtube.com/watch?v=p1iPJesZ4-M&t=3s

36
Canon Cinema Lens Technology
Super 35mm,* High quality 4K/HDR
– From the center to the periphery of our cinema lenses, a highquality 4K/HDR image is achieved for both
single focus and zoom lenses within the entire zoom range.
– Canon’s optical technologies are combined to help correct various aberrations and provide high contrast
while achieving a high resolution of about 80 lines/mm throughout the Super 35 mm sensor.
Focus Breathing Suppression
– Focus breathing is caused when the focus group moves
and exerts a “zooming” effect.
– In order to prevent this, cinema lenses implement a 3-
group inner focus method and a new floating method to
help minimize field angle fluctuation and achieve stable
framing.

37
11 Blade Aperture
– Halos from points of light at night or from rays of sunlight in shots
that show the sun take on the shape of the Iris blades.
– The odd number of blades make the iris aperture look circular
even when the Iris is contracted, enabling beautiful, round
highlight bokeh.
Warm Color Balance
– Cinema lens color balance, ideal for movie production,
reproduces warm skin tones. Color balance is strictly uniform
across all Canon cinema lenses making lens substitution during
the same scene possible.
– Anti-reflection film technology, including super spectral coatings
and thorough corrections for slight color variations caused by
glass components allow Canon lenses to achieve this effect.

38
Flange Back Adjustment
– A flange back adjustment mechanism is installed on the
lensmounts to allow for back focus adjustments.
Luminous Index
– The focus index on the front lens barrels is printed with luminescent
paint to improve visibility at night and in dark studio conditions.
Dust/Splash Resistant Seals and Casing*
– Our CN-E EF prime and Sumire Prime lenses use dust and splash
resistant rubber gaskets at the casing joints.

39
Color Reproduction
Quest for Cine Lens Spectral Response
Canon studied existing Cinema Lenses and the spectral
characteristics of Film and Digital Cine Cameras to
determine the ideal color balance of a cinema lens
X
X
Lens SpectralResponse
IR Filter
IR
Filter
OLP
Filter
ImageSensor
CFA
ND
Filter
RGB
Video
Processing
Linear Matrix
CFASpectral
X X
Imager SpectralResponse
Lens

40
Color Reproduction/Color Matching
Color Contribution Index (CCI)
– Computer simulation, employing the principles of the ISO Color Contribution Index (CCI) was employed to
achieve a very tight color reproduction match between the two lenses.
– The CCI, indicates the amount of color variation within a specific digital HD imaging system (or a film
imaging system), caused by different lens transmittance characteristics.

41
Color Reproduction/Color Matching
Color Contribution Index (CCI)
– Computer simulation, employing the principles of the ISO Color Contribution Index (CCI) was employed to
achieve a very tight color reproduction match between the two lenses.
– The CCI, indicates the amount of color variation within a specific digital HD imaging system (or a film
imaging system), caused by different lens transmittance characteristics.

– Has standard film industry metric pitch zoom, iris and focus gears, for Arri style accessories
– T stops, not F stops
– Distances measured from Focal plane of camera (video lenses are measured from front of lens)
– No extenders, no motors; lens barrel only
– Index marks are horizontal for assistant to read, on both sides of lens
– Primes have stainless steel mounts
– Zooms have more focus rotation than EFP style
– Primes are all same size front barrel
– Gears all line up at same location
Cine Style vs EFP Style
46

– Almost all high-end cinema lenses are PL mount, or “positive-lock” mount. At the end of the lens, there are four flanges
with a notch in each flange.
– Due to the increased crossover between still and video lenses, many cinema cameras are now offering Canon EF mount
options, including RED, ARRI, and Blackmagic.
• There are many third-party adapters that will allow you to use the EF glass you own on new Sony cameras.
– Sony’s increased presence has prompted some cinema lenses to be made with a native E mount, like the Fuji MK 18-
55mm and Fuji MK 50-135mm.
• This removes the need for a bulky adapter.
– High contrast and resolution and optimized MTF from corner to center of the lens
– High quality image in the total focus range from center to corner of the lens with minimal chroma aberration
– Natural image quality with minor amount of distortion (in lenses with fixed focus, distortion is very small)
– Focus Breathing: Viewing angle changing with focus function is very minor (breathing), so we have smoothness in focus
– Iris Smoothness in Cinema Lenses
– Color rendering very similar to the subject color and very small color temperature changing in digital cinema models.
Digital Cinema Lens Features
47

Optical Features
– Highest Contrast: New glass materials and advances in multilayer optical coatings have produced a lens having an
unparalleled contrast ratio
– High MTF: The contrast ratio is maintained at an impressive level far into the high spatial frequencies, and this combination
of contrast and high resolution produce a vibrant visual picture sharpness
– Minimized Ghosts and Flare: The optical and optomechanical design of these lenses took extraordinary innovative design
measures to counteract any undesirable optical artifacts stimulated by the effect of strong light sources in the scene
– Minimized Lateral Chromatic aberration: Anticipating the extreme detail of 4K imaging sophisticated new optical design
strategies were harnessed to minimize the wavelength dependence of optical magnification
– Color Matching: Computer simulation, employing the principles of the ISO Color Contribution Index (CCI) was employed
to achieve a very tight color reproduction match between the two lenses
– 11-Blade Iris: An 11-blade iris is employed in both lenses to achieve a beautiful natural round bokeh on out-of-focus
highlights
– Minimized Focus Breathing: Unique optical design has significantly minimized focus breathing facilitating a new level of
creativity in focus pulls
Digital Cinema Lens Features, Canon Cine Zoom Lens
48

Mechanical And Ergonomic Features
– Small in Size and Light in Weight:
• The new optical platform is unique in achieving extraordinary optical performance within a more modest size and
weight. This will further expedite efficient crew activity on set
– High Accuracy of Scales:
• Large, highly visible focus scales, allied with contemporary manufacturing techniques that ensure their high
accuracy, make these lenses especially operational-friendly to the cinematographer
– Back Focus Adjustment:
• The lenses are equipped with precision back focus adjustments. Respecting the desire of some cinematographers to
avoid inadvertent disturbance of this adjustment, the mechanism is concealed beneath a cover plate.
• For those accustomed to traditional back focus alignment (especially in multicamera television production) the
mechanism is readily accessed with a simple flat screwdriver.
– Uniform Size and Location of Gears:
• Both lenses have a common 136mm front diameter thus allowing use of common optical accessories.
• The location, diameter, and rotation angle of the lens gears are identical which further facilitates convenient
exchanging lenses on set
49
Digital Cinema Lens Features, Canon Cine Zoom Lens

Wide Converter
− A wide converter is useful for getting a large number of people into one scene in a narrow space.
− It shifts the focal length range of the zoom lens in the wide-angle direction, converting it to a more wide-
angle lens.
− If the W80I1A-8511 wide converter is attached to the J14a x 8.5 lens, for example, its focal length range
shifts from 8.5-119 mm to 6.8 -95.2 mm.
− The F-number remains exactly the same, so the illumination does not have to be changed.
− The minimum object distance becomes smaller in proportion to the square of the converter magnification,
so subjects can be shot closer-up. The lens can still be zoomed through the entire focal length range.
53
Master lens
With wide converter
attached
J14ax8.5
J18x8.5
8.5 119mm 6.8 - 95.2mm
8.5 - 153mm 6.8 - 122.4mm
Focal length 0.8x
Minimumobjectdistance (magnification)2 x (minimum object distance of master lens)
Zooming Usual Operation
F-number Same as usual
Change in focal length
Changes caused by wide converter

Afocal Converter
− An afocal system consists of a convergent lens and
divergent lens with the same focal point.
− Parallel rays entering the system leave it as parallel
rays, so there are no focal points or principal points
and no image is formed.
− The telescopes and finders of still cameras are
configured like this.
− An afocal system changes the focal length of a taking
lens with which it is combined.
− Magnification Factor
• If rays entering at height h leave at height h', the
afocal system has a magnification factor of h/h',
and it changes the focal length of the taking lens
by this factor.
54
Tele Converter
Wide Converter

Wide Attachment
− A wide attachment is used for the same purpose as a wide converter, but it has a simpler structure.
− With a wide attachment, focus is adjusted using the macro mechanism (or the flange-back adjustment
feature), so zooming is not possible.
− The attachment can be used only at the wide-angle end. (If the lens is zoomed, focus is lost.)
− If the lens does not have a macro mechanism and the focus is adjusted by the flange-back adjustment,
the flange-back must be readjusted when the attachment is removed to resume normal shooting.
55
Changes caused by attachment
Example: when used with
J14a x 8.5 lens
Focal lens
Fixed focal length (magnification)
x (wide-angle focal length)
Fixed focal length
Approx. 6mm
Zooming Not possible Not possible
Angle of view Fixed 72.5° x 57.6° diagonal 85.6°
Focus
adjustment
by macro mechanism
or F.B. adjustment
By macro mechanism

Fisheye Attachment
− The fisheye attachment is useful for achieving special effects by distorting the image the way a fisheye
lens does. Like the wide attachment, the fisheye attachment can be used only at the wide-angle end, and
the focus must be adjusted with the macro mechanism.
− With a master lens, the angle of view is:
− A fisheye lens introduces an intentional negative distortion, making the angle of view:
− When the fisheye attachment is used with the J14a x 8.5 lens, the focal length becomes 5.0 mm, and the
diagonal angle of view becomes 127.7°. Although that is less than 180°, it is enough to permit compositions
that would be unattainable with the master lens alone.
56
𝑤 = 2 tan−1
𝑦′
2𝑓
𝑤 = 4 sin−1
𝑦′
4𝑓
Focal length 5.0mm, fixed focal length focal length
Zooming Not possible
Focus adjustment By macro mechanism
Angle of view 101.7° x 76° diagonal 127.7°
Example:J14ax8.5withfisheyeattachment

Tele-Side Converter
− A tele-side converter attached in front of a zoom lens shifts its focal length range in the telephoto direction,
converting it to a more telephoto lens with greater reach. (For example, by a factor of 1.5)
− A tele-side converter does not have the F-drop that occurs when the internal extender is inserted.
• The F-number remains exactly the same as with the master lens alone.
− A tele-side converter is designed to be used only on the telephoto side of the zoom, however.
• If the lens is zoomed to the wide-angle side, the converter diameter would have to be so large that the
camera would become unwieldy.
• That is the reason for the word "side" in the name "tele-side."
57

Tele-Side Converter
− With a T1511-8511 tele-side converter on a J14a x 8.5 lens, peripheral eclipse occurs from about f = 80 mm
down to the wide-angle end, making this part of the range unusable.
− The minimum object distance (MOD) changes in proportion to the square of the magnification factor. For
the J14a x 8.5 and T1511-85II combination, for example, it changes from 0.8 mm to 1.8 mm.
58
(J14a x 8.5) + (T1511-85I1) 1.8 m
(J15 x 9.5) + (T1511-85I1) 2.14 m
(J18 x 8.5) + (T1511-9011) 2.03 m
Minimum object distance = (magnification factor of tele converter)2 x (minimum object distance of master lens)

Extender
− An extender is the accessory that brings in enlarged, close-up shots of players' faces in live sports
broadcasts. It is mounted between the camera and the lens to enlarge the image of the subject, or shoot
more distant subjects.
− It increases the focal length of the master lens, making it into a more telephoto lens.
• Inserting a 2.0 x extender into a J15 x 9.5 lens, for example, changes the focal length range from
9.5-143 mm to 19-286 mm.
− An extender also multiplies the F-number by the same amount, however.
− The 2.0 x extender doubles the F-number, leaving only 1/4 the speed (less speed), the same as if the lens
aperture were stopped down to half its diameter. The reason is that the focal length is doubled without
changing the lens diameter.
59

Built-in Extender
− Since extenders are useful and are frequently
used, many zoom lenses now have them built in.
− A large studio lens may have two or three built-in
extenders, giving the cameraman versatile lens-
work options.
− A built-in extender can be throught of as an
adaption of the afocal converter.
− Accuracy was formerly a serious problem with
built-in extenders, but production technology
has improved and their performance is now very
high.
60
Example of J15 x9.5B with extender
Master Lens With extender
Focal length 9.5 - 143 19 - 186
F-number 1.8 - 2.1 3.6 - 4.2
Lens speed
(relative value)
1 1/4

61
Canon Converters/Attachments and Extenders

Close-Up Lens
− A close-up lens is effective for close-up photography of, for example, flowers and insects.
− If the 82CL-UP1300H close-up lens is mounted in front of the J14a x 8.5 lens:
• when the focusing ring is turned to ∞, the lens is actually focused on a distance of 1.3 m
• when the focusing ring is turned to the minimum object distance of 0.8 m, the actual focusing distance is 0.5 m
− At a focusing distance of 0.5 m the object dimensions to fill the image format is 34 mm x 25 mm, so the
screen is filled by a subject about the size of a 35 mm side. Focusing becomes difficult, because the depth
of field is extremely shallow. The lens should be stopped down as far as possible.
− In principle, a close-up lens is a single convex lens. If the focal length (fc) of the close-up lens is 1.3 m, then
a subject placed at the object focal point (1.3 m from the lens) will be focused by the close-up lens to form
an image at infinity, which the zoom lens can shoot if the focusing ring is turned to the 00 mark.
62

Relation between Object Dimensions and Object Distance
− When focusing ring of lens is turned to infinity
f: Focal length of lens, fc: Focal length of close-up lens
 Object distance = fc , Magnification (M) = f/fc
 Object dimensions = (1/M) x (image size on CCD)
− When focusing ring of lens is turned to finite value
S: Distance setting on focusing ring, 𝒇𝟏: Focal length of focusing lens
 Object distance= fcS /(S + fc)
 m2: Magnification due to close-up lens, m3: Magnification due to zoom lens
Magnification: M
When object distance is enough (𝑓1 ≪ 𝑆)
Object dimensions = (1/M) x (image size on CCD)
63
Imaging range for J14a x and J15 x with close-up lens
Close-up lens
Master lens
Close-up 1300mm Close-up 800mm
J14ax8.5 (mm) 119 8.5
119
8.5
(Focusing scale) (m) (00) (0.8) (00) 0,8) (00) (0.8) (co) (0.8)
(Object distance) (mm) (1300) (495) (1300) (495) (800) (400) (800) (400)
Object dimensions (mm) 72x96 25x34 1009x1346 353x470 44x59 20x27 621x828 285x380
J15x9.5 (mm) 143 9.5 143 9.5
(Focusing scale) (m) (co) (0.95) (co) (0.95) (co) (0.95) (co) (0.95)
(Object distance) (mm) (1300) (549) (1300) (549) (800) (434) (800) (434)
Object dimensions (mm) 60x80 31x23 903x1204 467x351 37x49 25x18 556x741 370x278
𝑚2 =
𝑆
𝑓𝑐
+ 1 𝑚3 =
𝑓
𝑆 − 𝑓1
𝑀 = 𝑚2 × 𝑚3=
𝑆
𝑓𝑐
+ 1 ×
𝑓
𝑆−𝑓1
𝑀 =
𝑆
𝑓𝑐
+ 1 ×
𝑓
𝑆

Close-Up Lens
− The approximate field size when using a close-up lens can be obtained with the graph shown below. There
is not much difference in the field size of different lenses with the same focal length.
− When detailed objects such as documents are focused on at a short distance, problems such as lateral
chromatic aberration become noticeable.
− It is therefore better to avoid using a telephoto end for focusing at short distances. With the use of a close-
up lens, the same field size can be obtained at a middle focal length.
64

65
Canon Close-Up Lens
Close-up lens supported for SD

UV Filter, Skylight Filter
− A UV (ultraviolet) filter is nearly colorless.
• It absorbs short-wavelength ultraviolet rays
that the naked eye cannot see.
− A skylight filter has a light pinkish color.
• Used when shooting on clear days, it
removes ultraviolet, and prevents natural
light from giving a bluishgreen cast to
shaped foliage etc.
• A zoom lens contains so many lens
components that almost all ultraviolet light is
absorbed inside the lens.
• A filter is still advisable to protect the front
lens surface, however.
67
Transmittance of UV filter and skylight filter

ND (Neutral Density) Filter
− It uniformly reduces light of all wavelengths which enters a lens.
− It is used when the subject is too bright to be adjusted by the diaphragm alone.
68

69

− An ND filter can be used to control the light in order to shoot a subject such as a person or flower with a
large aperture.
− This creates a shallow depth of field, making the subject's beauty stand out against the defocused
background, and emphasizing the impression of three dimensions.
70

− The strength of an ND filter may be expressed as a density D, transmittance T, or exposure factor.
−The Strength of an ND filter may be express as:
• Percent Transmission (T)
 T is expressed as a decimal fraction (so 100% = 1).
• Optical Density (OD or D)
 It describes the amount of energy blocked by the filter.
• Exposure factor
 Commercial film lens filters are usually specified by the exposure factor.
71
𝑫 = −log 𝑻
𝑬𝒙𝒑𝒐𝒔𝒖𝒓𝒆 𝒇𝒂𝒄𝒕𝒐𝒓 = 𝟏/𝑻
ND filter type Transmittance Density
ND2 50% 0.3
ND4 25% 0.6
ND8 12.5% 0.9

− A dense ND filter absorbs light a little more strongly at shorter wavelength, so it may necessitate white
balance readjustment.
72

ND (Neutral Density) Filter, Conclusions
− The ND filters reduce the amount of incoming light to a level where the lens iris can provide correct
exposure for even bright images.
• It is important to note that the use of ND filters does not affect the color temperature of the incoming
light – they are designed so that light intensity is reduced uniformly across the entire spectrum.
• The ND filters can also be used to intentionally control an image’s depth of field to make it more
shallow.
• This is because ND filters allow a wider iris opening to be selected, and because depth of field
decreases as iris aperture (opening) increases.
73

Color Conversion (CC) Filters
− Color temperature expresses the balance of colors of a light source.
− A low color temperature is reddish. As the color temperature rises, the color changes to yellow, then blue.
• An amber filter reduces the color temperature, while a blue filter raises the color temperature.
− Television cameras are designed for the standard illumination in a television studio, which has a color
temperature of 3000K to 3200K, so an amber filter is necessary for outdoor shooting.
74

− The color conversion capability of a CC filter is measured in
• mired (micro-reciprocal degree: 1,000,000 divided by the Kelvin temperature)
• decamired (10 mireds) units.
− A filter that converts a color temperature 𝑇1 to a color temperature 𝑇2 has a decamired value of:
− A hand-held camera usually has two internal CC filters:
• a 16 decamired filter to convert the color temperature of sunlight (5600K) to 3000K
• a 10 decamired filter to convert fluorescent illumination (4300K) to 3200K
75
100000
𝑇1
−
100000
𝑇2
decamired:
100,000
𝑇
mired:
1,000,000
𝑇

− To find the decamired value of the correct filter to use,
read the decamired value of the illumination from the
chart at right, and subtract the decamired value of the
the standard color temperature of the TV camera
• 33.3 (=100,000/3000) if the standard color
temperature is 3000K
• 31.3 (=100,000/3200) if the standard color
temperature is 3200K
76
100,000
𝑇1
−
100,000
𝑇2
decamired:
100,000
𝑇
Natural light Artificial light
Color Temperature
of Light Source

Transverse and Longitudinal Waves
Direction of travel
Transverse Wave
Longitudinal Wave
77

– In an un-polarized transverse wave, oscillations may take place in any direction at right angles (90°) to the
direction in which the wave travels.
Wave Travel
Direction
Oscillation Direction
Polarization
78

– In an un-polarized transverse wave, oscillations may take place in any direction at right angles (90°) to the
direction in which the wave travels.
– By Polarization, vibration direction of wave are restricted.
– Polarization is a characteristic of all transverse waves that describes the orientation of oscillations.
Wave Travel
Direction
Polarization
79

− If the oscillation takes place in only one direction then the wave is said to be linearly polarized (or plane
polarized) in that direction.
Wave Travel
Direction
Linear Polarization
80

− This wave is polarized in y direction (E Oscillation Direction)
− Trace of electric field vector is linear
Linear Polarization
81
Electronic Field
Magnetic Field
Direction of Propagation

− Circularly polarized light consists of Two perpendicular EM plane waves of equal amplitude with 90°
difference in phase.
82
Circular Polarization
If this wave were approaching an
observer, its electric vector would
appear to be rotating counterclockwise.
This is called right-circular polarization.
Electric
Field
Note the 𝟗𝟎𝟎 phase
difference.

Circular Polarization
A clockwise circularly-polarized wave An anti-clockwise circularly-polarized wave
83

Light is an Electromagnetic Wave
– Un-polarized light consist of waves with randomly directed electric fields.
– Here the waves are all traveling along the same axis, directly out of the page, and
all have the same amplitude E.
– Light is polarized when its electric fields oscillate in a single plane, rather than in any
direction perpendicular to the direction of propagation.
Direction of motion of wave
z
x
y
E
v

B
v

v

E
B
E

v

This wave is polarized in y direction
The EM waves are transverse waves
84

Light and Polarization
85
Light Vibration
Light
Direction of Light Vibration
Polarized Panel

Polarization
86
Light Passing Through Crossed Polarizers
Polarizer 1
(Vertical)
Polarizer 2
(Horizontal)
Vertically
Polarized
Light Wave
Incident Beam
(Unpolarized)

Liquid Crystals and Polarizer
The alignment of the polarizer “stack” changes with voltage. 87

Circular, Linear and Unpolarized Light
88

Polarizer in Glasses
89
When sunlight reflects off a
horizontal surface, like a road
or water, it often becomes
concentrated horizontally.
This is called glare.
Vertical light is useful to the
human eye. Glare rnake5 it
difficult and uncomfortable to see.
Polarized Lens
Non-polarized Lens
Non-polarized sunglasses
don't block glare.
Polarized sunglasses block glare
and allow only useful vertical
light to enter your eyes.

Polarizer in Camera
A polarizer is used to intercept (stop/catch) light reflected from the surface of water or glass.
90
Unpolarized
Light
Direct light not reduced
as much as glare
Glasses transmit only
vertically polarized Light
Light partially polarized in the
horizontal plane by reflection
Glare greatly reduced

Polarizer in Camera
− A polarizer is used to intercept (stop/catch) light reflected from the surface of water or glass.
91

Polarizer
− A polarizer is used to intercept (stop/catch) light reflected from the surface of water or glass.
− Since light scattered by the atmosphere is partly polarized, a polarizer is also effective when shooting
subjects against a blue sky.
• It can suppress the sky and make mountains or other objects stand out.
− A polarizer is screwed into the threads of the hood, turned, and stopped in the position in which the
reflected light is removed.
− A polarizer:
• reduces the total amount of light to about 1/4
• changes the color balance, so the white balance must be readjusted.
92

Soft-focus Filter
− A soft-focus filter has a mat-like surface that imparts a soft, misty effect to the entire picture.
− Soft-focus filters are frequently used for lyric scenery shots.
93

Cross Filter
− A cross filter creates an cross or star of light by scattering rays from a strong light source in the subject in a
radial pattern.
− The brighter and more point-like the subject is, the better the effect is.
− Cross filters are often used to enhance night scenery or stage show broadcasts.
− Types of cross filter
• Cross filter: Scatters light in a four-pointed cross
• Snow cross filter: Scatters light in a six-pointed star
• Sunny cross filter: Scatters light in an eight-pointed star
94

95
Canon Adaptor Type Converters/Attachments

96
Canon Mount Converters for Different Image Format Size Cameras
− Canon offers a variety of Mount Converters to be used between a lens and a camera of different image
format sizes.
− Each converter will extend the effective Angular Field of View of the associated lens according to the Shift
Ratio listed below.

97
Fujinon Optical Accessories

Questions??
Discussion!!
Suggestions!!
Criticism!!
99

Broadcast Lens Technology Part 3

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