A Wider Perspective
Before you plunk down the dollars for those widescreen
laptops, better weigh the pros and cons mighty carefully.
TAKE A WALK down the laptop aisle of any major electronics
retailer and you will see that 4:3 aspect ratio screens are disappearing faster
than summer in Minnesota—and that’s not because they’re being
snapped up by consumers. Truth is, they’re no longer being produced; the
widescreens are taking over. In fact, some industry analysts estimate that widescreen
laptops will garner as much as 85 percent of the market within a year from now.
New laptops are also sprouting a funny-looking connector next to, or in place
of, the traditional VGA HD-15 jack.
Both of these trends will have a significant impact on technologyenabled teaching
design and planning. Widescreen Primer Non-CRT (cathode ray tube) display devices,
such as LCD/DLP monitors and projectors, have a fixed number of picture elements
(“pixels”) arranged in a grid pattern. The number of horizontal
and vertical pixels is considered the “native resolution.” The box
below details the resolution differences between conventional and wide screens.
This is not a comprehensive list of digital display resolutions, however; there
are products with hitherto-unknown resolutions being released all the time.
Widescreen Pitfalls
It’s important to know that many conventional-aspect LCD monitors (and
some projectors) don’t handle widescreen resolutions well. Actually, some
XGA and SXGA LCD monitors won’t display them at all. Early adoptors, who
have paid premium prices for widescreen projectors and large flat-panel monitors,
have found that not all widescreen is the same: Often, their display is 16:9
aspect while their source is 16:10 (or 15:9), or vice versa. This results in
the image being cropped, or in blank areas on the screen which are frequently
not symmetrical; the image is anchored on the left side of the screen, with
the right edge appearing as a wide blank band. Expect to see such aberrations
continue, as some manufacturers have found that it is more cost-effective from
a production-cost standpoint to make 16:10 aspect displays, rather than 16:9.
Then too, lack of product availability hampers efforts to modify technology-enabled
teaching system design to be ready for the impending widescreen revolution.
While there are an increasing number of wide-aspect projectors available, the
pickings of wide-aspect desktop LCD monitors are still slim. If you connect
a wide-aspect desktop or laptop running 1440x900 to a wide-aspect projector,
be sure to check to see if your desktop monitor can handle that resolution.
We’re seeing 17-inch monitors with 1280x768 resolution becoming available,
but in a limited number compared to the prevalence of widescreen laptops.
As if it’s not bad enough that your regular desktop monitors don’t
work with widescreen, other instructional tools may not be ready for widescreen
resolutions, either. Most, if not all annotation monitors (e.g., Smart Sympodium;
www.smarttech.com), are
conventional XGA or SXGA displays, and lack the capability to handle widescreen
images. And videoconferencing codecs and collaborative conferencing tools are
still based on conventional aspect ratios and resolutions. Clearly, any incorporation
and implementation of widescreen in the classroom must involve testing of existing
equipment to determine which systems are compatible and which will need to be
replaced.
Widescreen Benefits
It’s easy to lose sight of the benefits of widescreen, given the trouble
it has and will cause in educational institutions. But there are benefits; here
are a few:
- More screen real estate. For power users, this translates
into being able to see more windows/applications simultaneously. In Excel,
you see more columns. In PowerPoint, you can now have a nice picture next
to your list of bullet points.
- Bigger screen in the sameheight room. In most classrooms,
the limiting factor is not image width, but image height (based on ceiling
height and sightlines). This d'es not by itself guarantee better results,
since you would still have the same number of rows of data or bullet points,
but creative presenters will find ways to effectively use the extra display
room.
- Everybody’s doing it. Like it or not, most new laptops
carried by instructors and professors will be widescreen aspect, and not instructors
all will know (or think) to change their desktop resolution every time they
plug into a classroom display system. So, since you can’t fight it,
embrace it. After all, it looks ‘way cool.’
- Throwing DVI into the Mix The increasing resolution and
bandwidth requirements of computer-and HDTV-source displays, and the desire
to eliminate digital-to-analog and analog- to-digital components from sources
and displays, motivated the Digital Display Working Group (www.ddwg.org)
to develop the Digital Visual Interface (DVI) standard.
There are two common versions:
- DVI-I, which incorporates both traditional VGA analog graphics and the new
alldigital DVI signal in a single connector, where the VGA signal can be broken
out via adaptor, and
- the DVI-D, which lacks the analog pins and is digital only. In this application,
VGA is referring to analog video/graphics signals in general, not specifically
to the 640x480 resolution. The main benefits of DVI are: Displays talk to
the source and request the optimal resolution, without user intervention.
An XGA-native display will always get 1024x768, without the user having to
make four to five mouse clicks.
- Better image quality. Problems with image sync, tracking,
and pixel shift (caused by the vagaries of analog conversion and transport)
disappear, leaving the image exactly as it left the graphics card. More bandwidth.
DVI can handle higher resolutions than analog VGA connectors. The drawbacks
of DVI, from the technology- enabled teaching angle, are: Limited distance.
The basic DVI spec limits the distance to 5 meters. Most classroom cabling
from an instructor station to a ceiling-mounted projector is in the 30- to
50-foot range, so DVI is not practical without using extenders.
- D'esn’t play well with others. Because of the bi-directional
communication between the display and source to optimize the resolution settings,
you can’t use two different types of displays with a single DVI source.
You can use a distribution amplifier (DA) to drive multiple displays, if they
are identical models with identical DVI cable lengths. This rules out most
smart classroom applications, where the source computer is driving both a
desktop monitor as well as a projector. Computers with a DVI-I connector are
easy to connect with vintage VGA classroom systems, using a simple adaptor.
DVI-D outputs require a converter box costing $1,000 or more in order to connect
with a VGA classroom system.
The Bottom Line
Classroom systems and the people
who support them will be increasingly challenged to deal with the issues of
widescreen and DVI implementation, as these technologies are being strongly
driven by the consumer end of the market. Careful testing and evaluation of
each new piece of equipment with all of your existing hardware will be necessary
to prevent making expensive procurement mistakes.
| "CONVENTIONAL" RESOLUTIONS |
|---|
| Name | Horizontal Px | Vertical Px | Aspect Ratio |
|---|
| VGA | 640 | 480 | 4:3 |
| SVGA | 800 | 600 | 4:3 |
| XGA | 1024 | 768 | 4:3 |
| SXGA | 1280 | 1024 |
5:4 |
| SXGA+ | 1400 |
1050 | 4:3 |
| UXGA | 1600 |
1200 | 4:3 |
| QXGA |
2048 | 1536 | 4:3 |
| "WIDESCREEN" RESOLUTIONS |
|---|
| Name | Horizontal Px | Vertical Px | Aspect Ratio |
|---|
| EDTV | 852 | 480 | 16:9 |
| WXGA | 1280 | 720 | 16:9 |
| WXGA | 1280 | 768 | 15:9 |
| WXGA | 1365 | 768 | 16:9 |
| WXGA+ | 1440 | 900 | 16:10 |
| WSXGA | 1600 | 900 | 16:9 |
| WSXGA | 1920 | 1080 | 16:9 |
| WSXGA+ | 1920 | 1200 |
16:10 |
