Selecting a Projector
for Classroom Use
Video allows teachers to not only tell students what
they need to learn from a specific lesson, but show
them examples that helps develop understanding.
SYNERGY BROADCAST SYSTEMS
16115 Dooley Road
Addison, TX 75001
972-980-6991 or 800-601-6991
Analog TV is dead and quickly moving out of the classroom. The
projector seems to be most popular replacement for several
The picture is much larger than the typical 19” TV most
classrooms usually have installed and this is great because
now the students in the middle and back of the room can
actually see what’s on the screen.
The picture seems much brighter in most of the projectors
I’ve seen which is also great because the teacher can leave
the lights on and still use the projector in many cases.
The bad news is there appears to be more than 1,000 different
projector models on the market and they range in price from a few
hundred dollars to over $50,000.00. With that range of product
offerings how is a school to decide on a particular model that will
work best for all classrooms?
In an effort to find the best value we began a search with Google
and reluctantly determined that there was too much information
and too many models and manufacturers to make a comparison
simple. So, rather than make a brand or model recommendation it
makes sense to try and identify the important features to look for
when choosing a projector.
The following are thoughts and ideas on what should be
considered. There are many details, features and options but we
decided to take a big picture view and focus on these areas:
A lumen is a measurement of light output or brightness. The
American National Standards Institute (ANSI) established a
standardized testing procedure for projectors that involves
averaging several brightness measurements taken from different
locations. This number is called the ANSI lumen measure and
because it is an industry standard you can use the number
compare one projector to another to compare their relative
brightness. The larger the number, the brighter.
But how do you know what ANSI lumen number to look for? Does
room size or audience size matter? What about room lighting?
For classroom use it makes sense to use a projector that can
function properly without having to turn off all the lights or darken
the room to be able to see the picture. Teachers need eye
contact to foster interaction and read student engagement to
keep discussions active and moving. This also facilitates moving
back and forth between video and discussion mode to keep things
In looking at the different types of projectors it appears that the
very small portables (ultra portables) have between 1000 and 2500
lumens and the larger projectors for training rooms, conference
rooms and classrooms have 2500 to 7000 lumens. The web site
projectorpeople.com recommends the following guidelines for
lumens and lighting.
• 1000-1200 lumens for lights-off, low ambient light
• 1500-2000 lumens with some ambient light
• 2000-2500 lumens with bright ambient light
Ambient light is considered room light or existing room light that
originates from sources other than the projector. The brighter the
ambient light the brighter the projector needs to be.
Another consideration is audience size. The larger the audience
the larger the picture needs to be so the more light necessary to
overcome ambient light in a larger room. Projectorpeople.com
recommends the following guidelines for large audiences:
• 2500 lumens for less than a hundred with ambient light
• 3000 lumens for audiences of 100-200 with ambient light
• 5000 lumens for audiences of 100 or more under bright lights
Resolution is a way of relating to the sharpness of the picture. The
higher the resolution the sharper the picture, or the more detail you
can see. Resolution is typically displayed as 1024x768 where the
first number represents the width in pixels and the second number is
the relative height in pixels.
Most projectors are available in several resolutions such as,
• VGA (480x640)
• SVGA (800x600)
• XGA (1024x768)
• SXGA (1280x 1024).
One number is typically identified as the “native” resolution or
default setting and is usually the optimum setting for that particular
Here are some things to think about. PowerPoint presentations,
charts and most graphs will project just fine using a resolution of
800x600. High resolution graphics, photos and small print on a web
page or other fine detail will probably need 1280x1024. Your
classroom computer or laptop resolution is important as well and
should be the same as the projector so everything displays
The aspect ratio relates to the dimensions of your picture expressed
in units as the number of units wide by number of units high. Old
analog TV’s have a 4:3 aspect ratio, which means the picture is
almost square in appearance. The new flat screen TV’s are 16:9
and are much wider than they are tall. The U. S. is currently
transitioning from analog to digital TV where the older format is 4:3
and the newer format will be 16:9 so you will likely see and view
both formats until all formats of video and other content transition
to the new wider format. Check the specifications of any projector
you are interested in to see what aspect ratio it supports. Some will
only support 4:3 others will handle both.
Types of Projectors
LCD was the most common projector type but DLP is newer and
becoming more popular. DLP is typically the technology used in
the smaller portable and lightweight models.
LCD (liquid crystal display) projectors usually contain three
separate LCD glass panels, one each for the red, green, and blue
components of the image being fed into the projector. As light
passes through the LCD panels, individual pixels can be opened to
allow light to pass or closed to block the light. This modulates the
light and produces the image that is projected onto the screen.
DLP stands for Digital Light Processing and was developed by Texas
Instruments. Instead of having glass panels through which light is
passed, the DLP chip is a reflective surface made up of thousands
of tiny mirrors. Each mirror represents a single pixel. In a DLP
projector, light from the projector's lamp is directed onto the
surface of the DLP chip. The mirrors wobble back and forth,
directing light either into the lens to turn the pixel on, or away from
the lens to turn it off.
LCD Projectors: Strengths
-Richer color (better in rooms with ambient light)
-Draw less power
-Produce less heat
-Sharper image on data
LCD Projectors: Disadvantages
-More visible pixels
-Some screen door effect on certain video images
-Blacks come out lighter gray versus DLP projectors
DLP Projectors: Strengths
-Pixels less visible
DLP Projectors: Disadvantages
-Color filter wheel often produces soft but audible whine
-Poorer reds and yellows at full power
-Need more lumens than LCD, for rich colors
Weight can be a concern if you plan to move your projector from
classroom to classroom or if you mount it on the wall or the ceiling.
Obviously, if you are going to be moving your projector around
without the benefit of a cart the smaller the better and there are
many portable models from which to choose. Expect the portable
models to weigh between 1.5 and 4 pounds. Larger models will
weigh 7 – 15 pounds and heavier. The heavier the projector the
more expensive to mount on the wall or ceiling.
With all the new devices available today some care should be
taken to make sure the projector you select has all the connectors
you will need. Examples include a VGA connector for your
computer, USB for a document camera, S-video, composite video,
left and right audio, audio connectors for external speakers, and
HDMI for high def devices.
Take a test drive on the user controls. How easy is it to actually use
the projector’s controls? Is navigation easy or difficult? Is it intuitive
or will you need to keep the manual tethered to the machine?
Opt for simple controls whenever possible to reduce support calls.
Remote controls are usually included with each projector and third
party control panels can be used to control not only the projector
but other devices in the classroom as well.
Lamp Life and Energy Conservation
Projector lamps are expensive so look for projectors that have a
lamp life of 2,000 hours or greater. Also look for projectors that
have sleep modes or power conservation controls. These prolong
lamp life and also save on the school’s power bill.
Choose a projector with a zoom lens for more picture flexibility. The
zoom feature can be automatic or manual and should be a
feature on the remote control.
Keystoning is a distortion of the projected image and is caused by
either the projector or display surface being on an angle. As an
example, if the projector is on a table and displays on the wall the
top of the picture is likely to be wider than the bottom. Some
projectors can adjust keystoning within the projector. It’s a good
feature to have.
Throw is the distance between the projector and the display. A
short-throw projector can be very close to the screen where as a
long-throw projector must be farther back. Make your decision
based on where you plan to install the projector. What’s the
distance between the projector and the screen? To avoid having
students step on wires when using a table or cart, select a short-
throw projector so it can be positioned closer to the screen and
away from student desks Some projectors have interchangeable
lenses for short or long throw situations.
Most manufacturers provide calculators on their web sites to help
you determine the throw and screen size for each model as well as
the right size for a particular classroom dimension.
Lens shift is a great feature to have that enables the lens to shift up,
down, left or right to provide greater installation flexibility. By
shifting the lens one direction or the other you avoid the need to
physically move the projector or the mount to true-up the angle of
the picture to the screen or display surface. In a brief search of
several brands this feature appears on mostly high-end models but
it does not hurt to ask about it in your quest.
Choose a projector with a network connection if you will deploy
large numbers. Having this connectivity available usually means
the projector has administrative software that allows monitoring of
usage, lamp life and other measurable areas. A key consideration
here is the ability to remotely turn the power off to all units to save
on the electric bill and preserve the lamp.
In the end, it’s about setting priorities when in search of the perfect
projector. If you want some feedback I would encourage you to
talk with other schools that have purchased projectors and have
some experience. They can probably explain the mistakes they
made the first time they purchased a projector and you can learn
from their experience. If their projectors are a year old or older
don’t expect to find the same model available. This market
appears to change and update models on a very frequent basis.
You can also attend trade shows to visit all of the manufacturers.
Some of these shows will even hold a projector “shoot out” and
show them side by side so you can compare models.
Be careful when making replacement purchases as well. Minor
changes in the throw or angle of the lens from one projector to the
next might mean having to move all of your mounting brackets,
which can be an expensive undertaking so it makes sense to try a
replacement model on an existing bracket before you make the
http://www.google.com and search projectors to find resellers and
manufacturers. Please refer to the manufacturer’s web site for specific
http://www.projectorcentral.com/projection-calculator.cfm provides a screen
and throw calculator
This document is designed to provide recommendations to be used as guidance when considering
your projector needs. This is not designed to recommend one manufacturer over another or one
model over another but to provide you with some general guidelines to think about as you decide
what features make sense for your particular situation. Synergy Broadcast Systems does not sell or
endorse any projector brand or model.
About Synergy Broadcast Systems
Synergy Broadcast Systems is located in Addison, TX (Dallas). Founded in 1987 to serve the education,
cable, broadcast, government and healthcare markets the company’s solutions help facilities manage
and utilize video content in the most efficient and effective manner to capture, catalog, organize,
archive, report and deliver video for broadcast, video on demand, streaming and digital signage. The
company’s systems are modular, economically scalable and forward-focused to provide solutions that
solve video organization and delivery problems and provide migration options for future growth and
expansion. For additional information call 800-601-6991 or visit http://www.synergybroadcast.com.
VideoCourier is a suite of solutions designed for education to make video delivery to the classroom,
desktop, mobile device or meeting rooms easy. VideoCourier modules include content acquisition,
cataloging and search, multiple delivery methods, storage, archiving and reporting. For more
information on VideoCourier visit our web site at http://synergybroadcast.com or call us at 800-601-6991.