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Common terms:
ANSI lumens multimedia
SVGA XGA SXGA
LCD / DLP notebook
rear projection
PCMCIA cards RTB vs
swap-out lenses document
cameras keystone correction
What is an ANSI lumen?
This is measure of brightness as defined by the American
National Standards Institute. A brightness of 1,000 ANSI
lumens will project a good image in a well lit room. Higher
brightness allows larger images for presentations to more people.
What is a multimedia
projector?
Multimedia means that a projector will display data from
computers as well as pictures from televisions and video recorders.
Video only projectors cannot be used with computers.
What is SVGA resolution?
A computer image is made up of dots on screen.
The more dots, the better the quality of the image. SVGA simply
means the image is made up of 800 x 600 dots.
What is an XGA projector?
XGA projectors are made to display an high quality image
made up of 1,024 x 768 dots. Most modern notebooks use XGA.
Some XGA notebooks have the option of using higher resolutions: 1,280 x
1,024 SXGA, 1,600 x 1,200. If your notebook is using 1600 x 1200
for example, you would need to drop the resolution to XGA 1,024 x 768 to
match the projector. Using compression gives a poorer image.
What is a SXGA projector?
SXGA projectors are made to display an high quality
image made up of 1,280 x 1,024 dots.
LCD v DLP?
DLP and LCD projector technologies process light in different ways.
LCD is excellent on computer presentation as the colours on your
computer screen appear the same when projected. This can be
important when displaying your company logo within
presentations.
DLP gives better video performance as it allows sharper video images
with vibrant colours. Toshiba, who manufacturer DLP projectors have
included true colour correction software for use with computer
presentation.
You will notice that DLP projectors tend to be lighter and small than
LCD projectors.
LCoS (liquid crystal on silicon) technology is currently
available from a few manufacturers. LCD uses liquid crystals on glass
panels, and light passes through the LCD panels to the lens. DLP uses
tiny tilting mirrors to pass light. LCoS uses both these ideas, in that
it is a reflective technology that uses liquid crystals instead of tiny
mirrors. LCoS projectors typically use three LCoS panels, one for red,
blue and green.
LCoS projectors are mainly SXGA which is cheaper than
the other technologies to produce this resolution. This combined with
LCOS having minimum space between pixels means you get very clear images
especially on text. Larger projected images look clearer.
Will the projector work with my make/model of notebook?
Multimedia projectors are designed to work with all
notebooks, PC's and Apple Macs automatically. Some new notebooks
use XGA resolution which means that the screen display is made up of
1,024 dots across and 768 dots down. With these notebooks you will
need a projector whose native resolution is also XGA to get the best
results.
Most SVGA (800 x 600 dots) projectors will display XGA
but using 'compression'. Compression takes the 1,024 dots across
the screen and creates an image that will fit in 800 dots across.
This will display an image but you are losing 224 dots per line and
therefore reducing the quality of the image. The compression
quality of different manufacturer's projectors varies.
What is the difference between
an RTB and swap-out warranty?
A Return To Base (RTB) warranty means that if your
projector breaks down then you have to return your projector to the
manufacturer for repair. Depending on manufacturer, this can take
up to 2 weeks. A loan replacement swap-out warranty means that you
will be lent a projector whilst your projector is being repaired.
Usually this is the next working business day (Mon-Fri excluding bank
holidays) as long as you contact us or the manufacturer before 2pm.
I'm on a very tight budget. Which
projector?
Take a look at our projector
comparison charts.
What is a rear projector?
Projectors are normally positioned in the middle or back
of a room and project forward onto a screen. A rear projector will
display the image onto the screen from behind it. The main
advantage is that people cannot walk between the projector and screen
blocking out the image. All multimedia projectors can be used as
rear projectors. You would need either a rear projection screen or
mount the projector in a rear projection cabinet.
I need a projector for our large conference
room. Which projector?
Your will need a bright projector as you will need to
project your computer / video image onto a large screen. You will
need a minimum brightness of 2,000 ANSI lumens. Take a look
at our brightness comparison charts.
Why is there a choice of lenses on some of the
projectors?
Long-throw lens - Normally if you move a further
projector away from the screen, the larger an image is projected.
This is fine if you want to use your projector at the front of a
conference room/lecture theatre but it can be preferable to mount a
projector out the way at the back. The long-throw lens is used to
reduce the image size to fit a screen when the projector is mounted a
long way away. A semi long-throw lens works the same but for
shorted distances.
Short-throw lens - This is the opposite of a long-throw
lens. These can be used when a projector is mounted very close to
a screen to display a large image. This is often used in rear
projection systems.
What is a document camera?
This is available as an optional extra with some Toshiba projectors and is a
very useful feature. It lets you place books, papers, and other
objects under the camera and display them on the projector screen.
You can buy document cameras separately. We can even supply one
that connects to a microscope so that everyone in a laboratory can see
the results. Take a look at our document
camera and visualisers comparison charts.
What is the PCMCIA card
feature on some of the projectors?
This is available on some projectors which allows you to
give presentations without a computer. Microsoft PowerPoint
and Lotus Freelance Graphics presentations can be downloaded to a memory
card (PCMCIA) which the projector then uses to display the presentation.
You receive all the software, instructions and cables you need to do
this with your projector. You can save different
presentations on different PCMCIA cards which is especially useful if
more than one person will be using the projector.
The only drawback with the PCMCIA card is that it only
displays still images in the same way that a traditional slide projector
does. It cannot display PowerPoint slide transitions, animations,
MPEG movies, or sounds. You can still connect your computer and
video recorder to the projector for other presentations.
How many presentation slides can I fit onto a
PCMCIA memory card?
You can put around 20 slides onto a 4Mb card and 40 onto
an 8Mb card. This is a modest estimate because all slides will take up
different amounts of memory space depending on the graphics used.
What is digital keystone
correction?
If an overhead or multimedia projector is projecting
upward at an angle, then the image displayed is distorted. The top
of the image is longer than the bottom so that you do not get a nice
rectangle. This is known as the keystone effect. (A keystone
was the middle stone in an old stone bridge). Some of the
new projectors have keystone correction which means that the projector
can electronically compensate for this and display a rectangular image.
This normally corrects up to +/- 15 degrees.
What is a multimedia mobile trolley?
Multimedia mobile
trolleys allow you to wheel all your projector, laptop and screen
into a room when doing presentations on the road. The trolley then
folds into a stand for your projector and laptop. An ideal
solution when you are unsure if the presentation room has the right
equipment available.
Any more questions?
Then please contact us or get
a FREE
projector and presentation guide.
Comparison charts
We have put together comparison charts for projectors
from most major manufacturers so that you can compare projectors with
ease. Click here to view projectors
by price, manufacturer, weight/portability, brightness and resolution.
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