JONATHAN BRAWN
Principal, Brawn Consulting
Director, Digital Signage Experts Group
Director, Imaging Science Foundation Commercial
UNDERSTANDING
PROJECTOR TECHNOLOGY
PROJECTED GROWTH!
Pacific Media reports that the sale of projectors is increasing at 13% year over year, and forecasts that this will
continue in the near term.
The Digital Signage Federation reports that 25%-30% of digital signage utilizes projection of one type or another.
Advances in technologies such as liquid crystal on silicon have stoked interest in projection.
A LONG TIME AGO……
Projection of an image using a light source actually goes all the way back to the 1700s, but in modern times it began
with the projection of film, and in 2011 it has come full circle.
PROJECTION SELECTION: READY-SET-STOP
Before we begin to delve into the technical analysis of projectors for a given application, we must start with a needs
analysis, interacting with the customer to establish the parameters under which the selection will reside. We must
explore the following:
Objective/purpose of the system and how the projector selected will meet those needs.
Environment/space/orientation of the room including size, shape, obstacles, and any impediments that might affect the system.
Ambient light is a “necessary evil” but in all cases it decreases the quality of the image on the screen. We need to examine
where it comes from, quantify it, and see how we can control it.
Audience size and position.
Content to be displayed is important in terms of type, legibility, and quality required.
Service of the projector relates to accessibility, frequency/quantity, and availability of spare parts tied into MTBF estimates.
TCO relates to an analysis of the cost of the projector, serviceability, and how long the projector is expected to last before
replacement.
CATEGORIES: PICO PROJECTORS
A Pico or pocket projector is an emerging technology in the world of
a handheld devices.
Handheld projectors involve miniaturized hardware and software that can
project digital images onto any nearby viewing surface, such as a wall.
These units will often weigh less than a pound, and typically offer a built in
battery.
Some even provide a built in media player.
Generally less than 50 lumens of light output.
CATEGORIES: MICRO/MINI PORTABLES
This projector category is slightly larger than a Pico Projector and in terms of order of magnitude a “lot” brighter.
Micro Portables weigh from a pound to just over 2 pounds and will fit in the palm of your hand.
They feature light output from 50 Lumens up to 200 Lumens.
They can project up to a 100” diagonal image in a dark room.
Do not forget that this was in the range of the light output of the original CRT projectors!
CATEGORIES: ULTRA PORTABLE PROJECTORS
This category of projectors is all about portability for multiple uses in office,
schools and road warriors at under 4 pounds in weight and some as light as
2.4 pounds!
They feature 2k or greater light output and most include HDMI, VGA, svideo, composite video and USB.
Many include models that are available in XGA and WXGA resolution for
both 4:3 and 16:10 aspect ratios.
Examples:
Optoma EW330 at 2.4 Lbs (2200L)
Epson PowerLite 1730W at 3.74 Lbs (3000L)
Hitachi CPX5 at 3.8 Lbs (2500L)
CATEGORIES: PORTABLE PROJECTORS <10 LBS
The next step up the projection chain is still portable but might weigh as “much as”
10 pounds but the majority fall in the 7 to 8 Lb range.
They are brighter, provide better contrast and in most cases a better overall picture
experience mostly due to optical design and more advanced processor circuitry.
They also feature longer zoom lens ranges than the typical ultra portable.
Many in this class provide networking capability as well.
Examples:
Epson PowerLite 1915W 7.82 lbs. (4000L)
Hitachi CP-WX410 7.7 lbs. (3000L)
Optoma TX762 at 6.4 lbs. (4000L)
CATEGORIES: INSTALLATION PROJECTORS
Installation projectors are as the name implies intended for permanent system
installation.
In this regard they are not constrained by size, weight, limited optics, or
other impediments to image quality and performance.
This category focuses on the larger, brighter and more feature laden
projectors on the market. Although today, many companies find that smaller,
"portable" projectors are more than adequate for installation in training,
board and conference rooms, there is still large demand for the brightest and
the best.
Here we look at projectors, typically over 12 pounds, (and up to a couple
hundred pounds), that may offer interchangeable lenses, and typically offer
brightness from 3000 to 15,000+ lumens.
CATEGORIES: LARGE VENUE PROJECTORS
Large venue projectors are at the top of the performance tree. They are used for large auditoriums, conference
centers, high ambient light situations, and for large screens requiring the light output fro impact of the image. They
are also use predominantly for rental and staging applications.
They provide light output from 10K lumens up to nearly 35K Lumens!
They feature interchangeable lenses, electronic lens shift, and in most cases dual lamp capabilities.
The big guys may also include built in warp engines and edge blending processors.
The construction is strictly heavy duty and many are available with rigging fixtures for ease of flying and handling in
rental and staging applications.
CATEGORIES: SPECIALTY PROJECTORS
Specialty projectors due not fit a single category although they may
have elements in common with other types.
Short throw projectors
All in one projectors
Simulation projectors
Others
CATEGORIES: HOME THEATER PROJECTORS
Home theater projectors are closely related to cinema projectors in that they are
designed with the attainment of the best video image possible in mind.
Today's models are true HD capable at 720P or 1080P resolution
They are high performance single chip DLP or three chip LCD, or LCoS with some
higher end models using 3 chip DLP.
They feature better optics, higher performance processing “engines”, lens shift, and in
some cases auto iris designs.
They are also typically lower light output below 2K lumens since they will be used in
controlled light environments which also permits higher contrast.
After the installation, calibration is an important part of home theater projection
CATEGORIES: CINEMA PROJECTORS
Digital Cinema projectors are a special class of projector that meet specific standards
dictated by the Digital Cinema Initiative (DCI)
DCI calls for digital cinema projectors to have a resolution of 2K (2048×1080) or 4K
(4096×2160) .
Most digital cinema projectors are 3 chip DLP based.
Three main manufacturers provide these projectors, and as of 2010 there are over 6K
units with 80% in North America:
Christie Digital
Barco
NEC
Another technology by Sony called "SXRD" is a type of LCoS. They offer 4096x2160
(4K) resolution. These projectors suffer from low yield, and are not commonly
available.
WHERE CANON FITS
WUX4000
Large Venue Models
High resolution (HD/WUXGA)
7000lm or more
Installation Models
High resolution (HD/WUXGA)
SX Series
Weight
5kg or more
Portable Models
High resolution (SXGA+/WUXGA)
LV Series
Medium resolution (XGA/WXGA)
PROJECTION SYSTEM
EXAMPLES
BASIC PORTABLE SYSTEM
BASIC INSTALLED SYSTEM
ADVANCED INSTALLED SYSTEM
THE EFFECT OF DISPLAY
SPECIFICATIONS
THE EFFECT OF DISPLAY SPECIFICATIONS
In most audiovisual systems design, the display is the key component in the room. With this in mind, it is a
requirement to match the display to the environment, and to the explicit needs set forth in the sales proposal.
It is necessary to understand the specifications relating to display technologies, in order to properly design for
individual applications. The key considerations are:
Brightness
Contrast
Color Reproduction
BRIGHTNESS DEFINED
Brightness is the measurement of light falling on a surface, or light emitting from a source. It is most commonly
measured in two units, when relating to display technologies:
Lumens
A lumen is a measurement of light falling on a surface, such as a projector illuminating a screen.
A lumen is equal to one foot-candle falling on one square foot of area.
Properly specified, they are referred to as ANSI lumens, which infers adherence to the American National Standards Institute method
of measurement. Note: The original ANSI Standard is no longer a recognized reference.
This is essentially a measurement of projector horsepower, and is not what we actually see when we look at a screen.
BRIGHTNESS DEFINED
When dealing with projectors, the lumen measurement is not actually what we see. What we see when we look at the
screen, is reflected light, measured in the following units:
Foot Lamberts: The luminance (brightness) resulting from a surface emitting a luminance flux of one lumen per square foot. The
luminance of a perfectly reflecting surface receiving an illumination of one foot candle. Foot Lamberts are measured as reflected
light off the screen. This is the specification that we actually see when looking at a screen.
Foot Candle: The illumination from one candle at a distance of one foot. Equal to one lumen incident to one square foot. This
specification and measurement applies to ambient light in an environment.
BRIGHTNESS DEFINED
Types of Light Meters
There are two kinds of light meters in common use.
Spot Photometers or Spot Meters are used to measure a targeted area’s
illumination, such as measuring screen brightness. They have a designated
angle of acceptance, stated in degrees, showing how wide an area they
measure. The ANSI specification for a spot meter requires a 2° or less
measurement area.
Incident Light Meters are used to measure light falling on the meter.
They will have a white sphere that allows them to accept light over a
wide angle. Incident meters are used to measure ambient light.
BRIGHTNESS DEFINED
Measuring Projector Brightness
1
2
3
4
5
6
7
8
9
ANSI lumens are measured across a 9 zone average, using a 2° or less Spot Photometer (Light Meter)
CONTRAST DEFINED
Contrast is a measure of an image, defined as the ratio of the luminosity of the brightest value (white) to that of the darkest
value (black).
Contrast is stated as the ratio between maximum and the minimum brightness values. e.g. 100:1
In digital technologies, contrast is the difference between the luminance or brightness of an ON pixel and that of an OFF
pixel.
Off Pixel
On Pixel
Luminance for ON Pixel
Contrast Ratio =
Luminance for OFF Pixel
Note: In real world applications, the way we perceive contrast is a function of the display, seating, ambient light, content, and
even the color of the viewing environment.
CONTRAST DEFINED
Low Contrast Image
High Contrast Image
Note: Contrast is the element of a picture on a display that most notably drives
the perception of quality in a picture, i.e. increased depth of field and the
appearance of more details.
CONTRAST DEFINED
Full On/Off Contrast
This measures the ratio of the light output of an all white image (full
on) and the light output of an all black (full off) image. This is the
measurement most favored by manufactures as it yields a larger
number for the contrast ratio - typically 25% or more - than ANSI
contrast measurements for the same display device.
ANSI Contrast
This is measured with a pattern of 16 alternating black and white
rectangles - also referred to as the 'checkerboard' test pattern.
The average light output from the white rectangles is divided by the
average light output of the black rectangles to determine the ANSI
contrast ratio.
ANSI contrast represents a more fair way to test contrast ratio as the
presence of black and white at the same time is closer to the real
world environment rather than the all black or all white image used
during the full ON/OFF contrast measurement.
This renders the average reading obtained from the ANSI contrast
more realistic.
A 2° Spot Photometer is used
for these measurements.
CONTRAST DEFINED
Full On / Full Off Contrast Measurement
CONTRAST DEFINED
ANSI 16 Zone Contrast Measurement
CONTRAST DEFINED
Grayscale:
One cannot talk about displays without mentioning something on the grayscale performance of a display or video projector.
An analog grayscale is a smooth ramp of values going from completely black at one end, to completely white at the other.
The truth is that while contrast is an important attribute, it alone does not provide useful picture information - only grayscales
do.
It is the gray-scaling performance of an imaging device that is the single most important attribute to consider. This is dictated by
the processor in the display. A higher bit depth processor allows for more “steps” in the grayscale.
A larger number of grayscales would imply a device greater ability to display subtle detail in dark or bright scenes.
It is also this element that enables a display to create a wide color palette. Without shades of gray, contrast alone is of no use in
delivering image detail.
NEW ANSI CONTRAST RATIO STANDARD
ANSI/InfoComm 311M – Projected Image System Contrast Ratio (PISCR)
Informational Viewing (7:1)
The viewer is able to recognize what the images are on a screen and can separate the text or the main image from the background under
typical lighting for the viewing environment. There is passive engagement with the content (e.g., casual television viewing).
Basic Decision Making (15:1)
The viewer can make decisions from the displayed image. The decisions are not dependent on critical details within the image. The viewer
is actively engaged with the content (e.g., photos, typical informational presentations, public transportation informational displays).
Critical Decision Making (50:1)
The viewer can make decisions from the displayed image based on critical details within the image. The viewer is fully engaged with these
details of the content (e.g., architectural/engineering drawings, legal evidence, medical imaging and photography).
Full Motion Video (80:1)
The viewer is able to discern key elements present in the full motion video, including detail provided by the cinematographer or
videographer necessary to support their story line and intent (e.g., home theatre).
DISPLAY COLOR
When dealing with a display, another important specification is it’s color reproduction.
Color reproduction is the ability of a display device to reproduce a range of colors that will meet, or exceed, the
range of colors needed by the intended content to be shown on that display.
Display color reproduction relates to 4 specific terms that define how a display produces color, and in what amounts:
Primary color
Colorspace
White reproduction or color temperature
Gamut
DISPLAY COLOR
What is color?
Color is a perceived property of light.
Light is essentially a wave of electromagnetic energy, measured in nanometers (nm), that falls within the range of frequencies
perceived by the human eye.
Different wavelengths of light are perceived as different hues, that we define as colors.
The main color “categories” we recognize are red, orange, yellow, green, blue, indigo, and violet.
White and black are not true colors, but really the presence of ALL wavelengths of light (white) or absence of all wavelengths of
light (black).
DISPLAY COLOR
How does display color work?
Display devices, whether flat panel or projection, and regardless of
technology, all use the additive mixing process to produce color.
Additive mixing is the combination of wavelengths of light to produce
colors, based on the use of reflected light. Printed or dyed materials use
subtractive mixing, or the absorption of wavelengths of light, to
produce color.
A display device will achieve this by establishing 3 fixed hues, or colors,
of light, called primary colors, and combining them together in various
amounts to create other colors, and in equal amounts to create white.
The three primary colors used by the display industry are red, green,
and blue.
DISPLAY COLOR
Understanding Colorspace
The chart shown to the right is the CIE Chromaticity Diagram. This
chart displays all of the colors that make up the range of human vision,
and provides us with a way to measure, chart, and understand how a
specific color, or range of color, fits into our sight.
No display device produced today can replicate all of the wavelengths of
light that make up human vision, and no content produced today
requires the entirety of the area shown. However, content will frequently
be produced with a range of colors in mind, known as a colorspace.
A colorspace is a group of three sets of coordinates, corresponding to
three primary colors shown on the CIE Chromaticity Diagram. There
will be lines drawn on the diagram, to define a triangle. This triangle
now contains the range of colors that make up that colorspace.
Different types of content can require a display to be capable of
producing a specific colorspace, and either meeting, or exceeding the
range of colors that make up that colorspace.
DISPLAY COLOR
What is color temperature?
Color temperature, sometimes called white balance, is a metric by which
we can relate how a display is configured to reproduce white, and how
warm (reddish) or cool (bluish) it will be.
Color temperature is measured based on the scientific measurement of
heat, called Kelvin. The more Kelvin, the cooler, or more blue, the white
will be. The less Kelvin, the warmer, or more red, the white will be.
The ideal standard for color temperature, based on standards from the
Society of Motion Picture and Television Engineers (SMPTE) and the
Digital Cinema Initiative (DCI) is 6500 Kelvin, which relates to optimal
sunlight.
Proper reproduction of white is required to display content correctly, so
the display’s calibration of color temperature should be set to match what
the content is developed for.
DISPLAY COLOR
Display Gamut
A display’s ability to reproduce color is known as it’s gamut. A gamut is essentially the colorspace a display is capable of
producing.
This will commonly be shown as a triangle, drawn over a simplified CIE Chromaticity Diagram.
A display’s color gamut can also be related as a percentage of a specific colorspace, such as “98% of NTSC”, or “108% of
REC709”.
It is important to ensure that a display device of any type is capable of producing a gamut covering as much of the colorspace
required by the intended application as possible, or to even produce a greater gamut than required, in order to properly render
the content.
DISPLAY RESOLUTION
In digital displays, resolution is the number of pixels (individual picture elements) contained on a display, expressed in
terms of the number of pixels on the horizontal axis and the number of pixels on the vertical axis. e.g. 1920x1080
The sharpness of the image on a display depends on the resolution and the size of the display. The same pixel resolution
will be sharper on a smaller display and gradually lose sharpness on larger display because the same number of pixels are
being spread out over a larger number of inches.
1024x768
1366x768
1920x1080
SIGNAL FORMATS
Aspect Ratios
What is an aspect ratio? Aspect ratio is typically described as the ratio of screen width to screen height.
There are two common aspect ratios, the first is that of a standard television which has a 4:3 (referred to as "4 by 3") aspect
ratio. Also note that the television aspect ratio is listed as 1.33:1. This is another way of listing aspect ratios—dividing the width
by the height (e.g., 4/3 = 1.33). This is referred to as "1.33:1" or "1.33 to 1". A widescreen display, such as a plasma or LCD
panel, will usually have a 16 by 9 aspect ratio (16:9). Since 16/9= 1.78, the aspect ratio is also known as "1.78:1" or "1.78 to 1".
SCALING – MAKING IT FIT!
By definition, a digital display can also be referred to as a fixed matrix display, with a finite number of horizontal
and vertical picture elements, or pixels. e.g. 1024x768
In many instances the resolution of the video signal, and the physical resolution of the display do not match. The
“mismatch” requires what is known as scaling.
Scaling refers to a process of taking a higher resolution signal, and modifying it to be displayed on a lower resolution
device, or a lower resolution signal, and modifying it to be displayed on a higher resolution device.
This process is a complicated mathematical algorithm that analyzes the video signal and performs the adaptation of
the resolution.
SCALING ALGORITHM
A fundamental understanding of the way basic scaling works is illustrated below.
Take 2 adjacent pixels of the signal
and divide by 2
Scaling is an interpretation or
interpolation of a lower resolution
or higher resolution signal into a
native resolution chip
Take 2 adjacent pixels and add
together
Signal Resolution
800x600
Native Resolution
1024x768
Signal Resolution
1280x1024
PROJECTOR DISPLAY
TECHNOLOGY
LCD PROJECTOR TECHNOLOGY
LCD CONSTRUCTION PRINCIPLE
To create an LCD, you take two pieces of glass with
polarizing films applied, which are assembled together
with a carefully controlled gap between.
When liquid crystal material is introduced to this cell,
the layers adjacent to the glass will align, resulting in a
helical structure of molecules between the two glass
plates.
As light strikes the first plate, it is polarized.
The molecules in each layer then guide the light
through the display, changing the angle of polarization
to match.
LCD CONSTRUCTION PRINCIPLE
When light reaches the final layer of the crystal
material its plane of polarization will have been rotated
through 90 degrees and since the plane of polarization
matches the plane of the polarizing film, light will be
transmitted.
If we apply an electric field to liquid crystal molecules,
they untwist.
When they straighten out, they change the angle of
the light passing through them so that it no longer
matches the angle of the top polarizing filter.
Consequently, no light can pass through that area of
the LCD, which makes that area darker than the
surrounding areas.
LCD ADDRESSING
Data Lines
Pixel
LCD COLOR PRODUCTION
LCD projectors utilize three LCD panels or chips as the imaging devices, one for each of the primary colors. The
lamp approximates pure white light from which the colors of the spectrum can be extrapolated.
LCD – THE PROS AND CONS
Inexpensive
Established, long term technology
3 channel color reproduction
LED lamps need no replacement
Low optical efficiency
Image performance (low fill factor, lower contrast)
Image retention
Not appropriate for 24/7/365 operation
Dust filters
DLP TECHNOLOGY PRINCIPLES
DLP OPERATION
A DMD chip is a digital light switch. It has on its surface several hundred thousand microscopic mirrors arranged in
a rectangular array which correspond to the pixels in the image to be displayed.
The mirrors can be individually rotated ±10-12°, to an on or off state.
In the on state, light from the projector bulb is reflected into the lens making the pixel appear bright on the screen.
In the off state, the light is directed elsewhere making the pixel appear dark.
To produce grayscales, the mirror is toggled on and off very quickly, and the ratio of on time to off time determines the
shade produced.
DLP OPERATION PRINCIPLES
DLP OPERATION PRINCIPLES
DLP - THE PROS & CONS
Optical efficiency and sealed optical block
Response time
Color reproduction (3 chip)
Ultra compact design (single chip)
LED lamps need no replacement
24/7 Capable with no burn in
Color reproduction (Single chip with color wheel, single chip with LED)
Possible “Rainbow Effect” (single chip)
Cost
LCOS TECHNOLOGY
WHAT IS LCOS?
LCOS (Liquid Crystal on Silicon) is a reflective micro display
technology based on a silicon chip.
The electronic circuits controlling the liquid crystals are fabricated on a
silicon chip, which is coated with a highly reflective surface.
This results a very high fill factor (image is less pixilated) because the
circuitry is behind the pixel and does not create an obstruction in the
light path (“screen door” effect).
Using standard CMOS processes, micro displays with extremely small
pixels, high fill factor (pixel aperture ratio) and low fabrication costs
can be created.
LCOS OPERATION PRINCIPAL
An LCoS chip has several layers.
Glass layer
Liquid crystal layer
Reflective layer
Control layer
A video signal is introduced to the control
layer, and that sends an electrical signal to
the liquid crystal layer, operating it like a
standard LCD.
The light from the illumination source
passes through the liquid crystal layer, and
reflects off of the reflective mirror layer.
Glass
Liquid Crystal
Reflective (Mirror) Layer
Control Layer
Silicon Substrate
TYPICAL LCOS OPTICAL ENGINE
Steering
Mirror
Dichroic
Filter
Blue
PBS
Blue LCoS
Lamp &
Reflector
Green
PBS
Integrator
Condenser
Rod
Projection Lens
Green LCoS
Red LCoS
Prepolarizer
Dichroic Filter
Red
PBS
CANON AISYS SYSTEM
Canon's AISYS optical system makes it possible to incorporate LCoS reflective LCD panels in a more compact projector than
previous LCoS engine designs.
Despite its compact size, the optical array effectively controls the light from the projector lamp, maximizing the potential of
the LCoS panels to achieve high levels of both brightness and contrast.
CANON AISYS SYSTEM
Canon’s proprietary AISYS optical system permits incorporation of high-performance LCOS reflective
LCD panels in a compact projector. Despite its extremely compact size, the optical array effectively
controls light to maximize the potential of the LCOS panels, achieving unprecedented levels of both
brightness and contrast.
AISYS advantages
High resolution
High luminosity (brightness)
High contrast
Superior color reproduction
Compact size
Color Separation/Recombination
System
Functioning to separate and
recombine colors in light, the
PBS* has been re-engineered for
more compact size.
Illumination Optical System Projection Lamp
Efficiently creates highly
Highly efficient, long-lasting
uniform light
AC lamp
CANON AISYS SYSTEM
To achieve both brightness and high contrast, the AISYS optical system
independently controls light in both vertical and horizontal directions
The AISYS optical system separates and controls the vertical and horizontal components of the light from the projection lamp.
The vertical component of light is transformed to conform to the optical axis, and light that cannot be properly polarized by the
PBS is removed, to ensure high contrast. The horizontal component of light can be properly polarized, so incoming light is
converged to increase brightness. This independent control of light enables the AISYS optical system to achieve the optimum
combination of brightness and high contrast.
Symmetrical light source
Vertical light
Horizontal light
Vertical light is flattened parallel to the
optical axis to ensure high contrast.
The PBS is capable of properly polarizing
horizontal light, so incoming light is
converged to boost brightness.
CANON AISYS SYSTEM
How to achieve a combination of brightness and high contrast?
LCOS-based projectors require a PBS (Polarization Beam Splitter) to transmit or reflect the light according to the direction in which it is polarized. Light enters
the PBS from various directions, similar to the LCOS panel illustration below. Among this is light that cannot be split by the PBS; this light can degrade the
contrast of the projected images.
Light striking a single point on an LCOS panel
Light that is not
properly polarized
Reasons for diminished contrast
LCOS-based projectors rely on a PBS unit to direct and control light that forms the projected image.
As illustrated in the diagram at right, light that penetrates the PBS at an angle cannot be adequately
redirected, resulting in light leakage.
When light leaks into black areas of the image, the image is brightened, producing dull-looking
images with inadequate contrast.
Light leakage from the PBS is one of the main cases of inadequate contrast.
Light leakage degrades contrast
Projection lens
Light
leakage
PBS
Surface of
PBS
LCOS
Light leakage occurs when light strikes at an
angle
LCOS – THE PROS AND CONS
The highest resolution fixed matrix device (>4K x 2K, up to 8K)
Highest contrast display technology (>3000:1)
Color reproduction accuracy
Highest fill factor
Optical efficiency (with AISYS)
Yield issues
Cost
Optical efficiency (without AISYS)
TECHNOLOGY COMPARISON
LCD vs. DLP vs. LCoS
COMPARISON OF LCD, DLP, AND LCOS
LCD
60%-70% Fill Factor Transmissive
DLP
85% Fill Factor Reflective
LCoS
93% Fill Factor Reflective
CANON LCOS ADVANTAGES
High Fill Factor
Better contrast ratio due to lower light leakage
Smoother, more cinema-like image quality
Optical Efficiency - AISYS system maximizes lamp light output
Better color reproduction
12bit color processing
Superior color brightness due to 3 separate color channels
Lens quality
Serviceability
Replaceable optical filters
Lower TCO
Cost/Performance ratio
PROJECTOR LAMPS
WHAT IS A PROJECTOR LAMP?
The technical description of a projector lamp is that it is an
ultra-high pressure metal halide or mercury vapor arc lamp.
A projector lamp operates by sending an electrical current
across an electrode gap that is full of ultra-high pressurized
gas.
The electricity lights the inert gas or mercury vapor which
then causes the lamp to emit a light with an extreme
intensity or brightness.
Projector lamps are a extremely complex technology that are
very costly to manufacturer, therefore the price of projector
lamps tends to be high.
PROJECTOR LAMP BRIGHTNESS
Projector lamps do not achieve their full light output immediately after starting.
They require between 1 to 15 minutes, to reach 90% of their full light output.
After a lamp has been on for a period of time and then extinguished, it cannot be immediately turned back on.
Before the lamp can be turned back on, the arc tube must have a chance to cool down or the lamp will not restart.
This period of time is called the restrike time.
As the lamp ages the restrike time become greater to the point the lamp starts to noticeably flicker at which point it
is unusable.
PROJECTOR LAMP LIFE
Various operating conditions can affect the average life of lamps.
One of the most important factors is burning position. Position-oriented lamps (designed to burn in a certain position) are tested
and rated based on their designated position. Burning these lamps in other positions can dramatically shorten life, lumen output,
and color.
Universal lamps can be burned in any position, but as a result, they sacrifice life expectancy and lumen output in some operating
positions.
Published "rated life" for universal lamps are based on the lamps being burned in the vertical position. "Rated life" for lamps
burned in the horizontal position is 75% of the published rating for the vertical application.
Lamps, like most electromechanical devices, have a shorter life the more they are turned on and off.
Other factors can also affect lamp life, such as high or low operating voltages, marginally operating control devices (ballasts,
capacitors, etc.), extremely high operating temperatures, among other conditions. Combinations of these factors can multiply the
reduction in "rated life".
LAMP LIFE
"Economic life" is a much better description of actual lamp life than rated life. It refers to the hours of operation a
lamp is designed to provide in terms of optimum light output, aesthetic quality, and economic energy consumption.
The "economic life" of lamps is generally defined as 60% of the lamp’s rated life.
"Rated life” does not account for the lumen depreciation, color shifting, and loss in efficacy that always occur as
lamps age.
First Knee
Second Knee
PROJECTOR LENSES
PROJECTOR LENSING AND BRIGHTNESS
How do lenses affect projector brightness?
Lens specifications tell us two things:
The focal length of a zoom lens is generally expressed in millimeters (Example 50-75mm). The zoom ratio of 50 to 75mm is
about 50%, or 1.5:1. This means that the system designer can vary the size of the projected image by 50% without moving the
projector closer or further back.
The second specification of a lens is the aperture. This is the opening in the lens that light passes through, expressed in as an fstop (Example f/2.5-3.0). F stops are a guide to comparing the brightness output of two projectors with similar focal length
lenses. The lower the f-stop, the more light the lens will emit at a given focal length.
Zoom lenses will vary in light output based on where they are in the zoom range. They have higher aperture ratios at wide angle,
producing higher brightness, whereas at telephoto they have narrow apertures, allowing less light to pass through.
CANON LENS ADVANTAGES
Standard zoom lens
Projection distance
（100 inches）
Projection ratio
F
value
Wide single focus lens
Telephoto zoom lens
3.2m to 4.8m
1.72m
4.7m to 8m
1.5 : 1〜2.25 : 1
0.8 : 1
2.2 : 1〜3.75 : 1
1.89-2.65
2.0
2.0-2.8
CANON LENS ADVANTAGES
Low light loss due to interchangeable lenses
Standard zoom lens
Wide single focus lens
Telephoto zoom lens
WUX4000
4,000lm
3,700lm
4,000lm
Brightness ratio with standard zoom
lens
−
−7%
±0%
Image quality change is minimal even during lens shift
With Lens Shift
No distortion
With Lens Shift
No change in aspect ratio
With Lens Shift
Low light loss
CANON LENS ADVANTAGES
Minimal chromatic aberration
Since the refractive index of light penetrating the lens differs depending
on the color, all colors do not form the image at one point, and the
occurrence of color drifting is called chromatic aberration.
In the WUX4000, the newly designed UD lens (Ultra Low Dispersion)
developed from the EF series camera lens technology, reduces chromatic
aberration to almost zero, realizing vivid images with minimal color
drifting.
Minimal image quality change
Using a superior floating lens element system, high quality
images can be projected throughout the entire zoom range.
Standard zoom lens
Aspheric lens
UD glass
Independently floating
Low distortion
What is a floating system?
A lens system in which 2 lens elements move independently when zoomed.
Canon provides superior low
distortion using high-level
aspheric lens technology.
Television
curvature 0.1% or less
CANON COLOR PROCESSING
SUPERIOR REPRODUCTION OF COLOR
Canon provides superior color reproduction by utilizing a new 6 axis color processing system, with an advanced 3D Look Up Table (LUT)
This provides the capability to increase the gradations of color by adding brightness in addition to hue and saturation.
Larger 3D look up table improves signal reproduction by increasing the amount of color data stored in the processor.
Traditional 6 axis color adjustment
New 6 axis color adjustment
Expanded 3D-LUT
Traditional 3D-LUT
New 3D-LUT
Contrast
Before color adjustment
Color adjustment with 6 axis adjustment + 3D-LUT
IN CONCLUSION…
TAKING THE PROJECTOR OUT OF THE EQUATION
When designing an A/V system with a projector, it ultimately comes down to three factors:
Ambient light in the environment
Projector selection
Screen selection
By providing superior LCoS technology, with the best contrast ratio and color reproduction, paired with Canon lens
technology, Canon projectors eliminate the factor of the projector from the equation.
THANK YOU!
THANKS FOR ATTENDING!
If you would like more information, please contact Brawn Consulting:
www.brawnconsulting.com
Alan C. Brawn, CTS, ISF, ISF-C, DSCE
alan@brawnconsulting.com
Jonathan Brawn, CTS, ISF, ISF-C, DSCE
jonathan@brawnconsulting.com