|
Brightness:
A measure of the total light output of a projector.
Bright Mode:
Allows the projector to disengage the color wheel with a manual switch,
resulting in a projected monochromatic image at over twice the brightness.
When in Bright Mode, the image will not be in color, but with a full
greyscale. This is ideal for projecting spreadsheets, x-rays, and any full
text applications.
Computer Compatibility:
The types of computer resolutions that are displayable on a projector. See
also compressed resolution and native resolution.
Compressed Resolution:
Most projectors automatically accept images that are of greater resolution
than the native (true) resolution of the projector. The resulting image is
scaled to fit the native resolution of the projector using a variety of
scaling algorithms. The nature of compression in a digital device means that
some image content is lost.
Contrast Ratio:
The ratio between the brightest white and darkest black. In a normal front
projection system, the ambient light limits the effective contrast ratio to
a level lower than the contrast ratio of any modern projector, so this ratio
does not affect image quality. In a rear projection system, high contrast ratios
are possible, so this specification becomes an important factor to consider.
Digital Pan/Zoom:
Allows any area of the image to be blown full screen. Useful for examining
sections of spreadsheets and close-up details of photos. The pan control allows
the presenter to select the magnified area.
DVI-I:
A connector that has the capability of carrying either digital or analog video
signals. This connector can be converted to the common 15-pin VGA connector with
a DVI-I to VGA adapter making the input compatible with standard VGA cables.
DVI-D:
A connector that has the capability of carrying digital video signals. This
connector is very similar in appearance to the DVI-I connector but lacks the ability
to carry analog video signals.
EcoMode:
An option that increases lamp life by lowering lamp ballast power. When this feature
is engaged, the projector's brightness level will be reduced by approximately 20%.
Greatest Displayable Resolution:
Most projectors automatically accept images that are of greater resolution than the
native (true) resolution of the projector. The resulting image is scaled to fit the
native resolution of the projector using a variety of scaling algorithms. The nature
of compression in a digital device means that some image content is lost. See also
XGA, SXGA, UXGA.
HDCP (High bandwidth Digital Copy Protection):
A copy protection scheme devised by Intel that encrypts digital video content to
prevent the making of copies. Programming that is encoded with HDCP requires an HDCP
compliant display device in order to view the program. HDCP encryption is planned
primarily for protecting high definition and pay-per-view broadcasts and some
digital recordings.
Keystone Correction:
Keystone is a distortion of the image caused by projecting at the wrong vertical
angle. Digital keystone correction produces an inverse effect that cancels this
distortion. This technique produces excellent results with video, but introduces
some noticeable artifacts with computer projection. See also lens shift.
Lens Shift:
The lens shift feature, sometimes called optical keystone correction, allows the
projector to be placed anywhere within its offset range without having any keystone.
Unlike electronic keystone correction, which does the same thing electronically, power
lens shift has no digital artifacts. This feature also makes it possible to stack two
or more projectors without a ghosting effect for improved brightness and fail-safe
reliability.
Lens shift can be expressed either in degrees or as a ratio between the throw distance
(distance between the projector and the screen) and the vertical offset distance
measured at the screen surface. To convert between them, use the formula:
(Offset Distance) / (Throw Distance) = TAN (Offset Angle).
MSRP:
Manufacturer's Suggested Retail Price
Microlens Array:
Miniature lenses deflect light away from the inert areas surrounding each pixel, into
the active areas. This permits more light to pass through the LCD panels, boosts light
output, and reduces the screen door effect.
Native Resolution:
Resolution is defined by the number of individual dots (pixels) that a display uses to
create an image. The total number of pixels in a display is expressed as the number of
horizontal pixels by the number of vertical pixels. See VGA, SVGA, XGA, SXGA, UXGA and
WXGA for definitions of some of the more common display resolutions.
Native Screen Format:
This is the screen format, or aspect ratio, when all of the projector's pixels are being
used. When a projector is used in its native format, it will achieve its rated and greatest
light output. If a projector's native resolution is 4:3, when it is used at 16:9 a band of
pixels along the top and bottom will not be used; since only 75% of the pixels are being
used, the projector's brightness will be only 75% of its rated brightness. The same is true
when a native 16:9 projector is used at 4:3 - 25% of its rated brightness will be lost. All
other things being equal, it is best to choose a projector whose native format matches the
format that will be used most often.
PC-Less Presentation:
Projector accepts a standard PCMCIA memory card and can play back a saved PowerPointŪ
presentation without a computer.
SVGA (800x600):
SVGA is used to define a specific display resolution. An SVGA display has 800 horizontal
pixels by 600 vertical pixels, giving it a total display resolution of 480,000 individual
pixels that are used to compose the image delivered by a projector.
SXGA (1280x1024):
SXGA is used to define a specific display resolution. An SXGA display has 1280 horizontal
pixels by 1024 vertical pixels, giving it a total display resolution of 1,310,720
individual pixels that are used to compose the image delivered by a projector.
Screen Format:
The screen format, or aspect ratio, is the ratio between the width and height of the
image. Standard TV, VGA, SVGA, XGA and UXGA are all 4:3 - the height is 3/4 of the width.
HDTV has an aspect ratio of 16:9; SXGA, 5:4.
Throw Ratio:
A ratio between projection distance and width of image. For example, a throw ratio of
1.8:1 means that the projector must be 18' away from the screen to result in a 10' wide
image.
UXGA (1600x1200):
UXGA is used to define a specific display resolution. A UXGA display has 1600 horizontal
pixels by 1200 vertical pixels, giving it a total display resolution of 1,920,000 individual
pixels that are used to compose the image delivered by a projector.
VGA (640x480):
VGA is used to define a specific display resolution. A VGA display has 640 horizontal pixels
by 480 vertical pixels, giving it a total display resolution of 307,200 individual pixels
that are used to compose the image delivered by a projector.
XGA (1024x768):
XGA is used to define a specific display resolution. An XGA display has 1024 horizontal
pixels by 768 vertical pixels, giving it a total display resolution of 783,360 individual
pixels that are used to compose the image delivered by a projector.
WXGA (1366x768):
WXGA is used to define a specific display resolution. A WXGA display has 1366 horizontal
pixels by 768 vertical pixels, giving it a total display resolution of 1,049,088 individual
pixels that are used to compose the image delivered by a projector.
Zoom Range:
The ratio between the smallest and largest image size by adjusting only the projector's zoom
lens.
|
