disappearing slideshow
sudden unresponsive laptop 
ill-timed technical glitch

Make laptops & projectors cooperate
Some of the technical problems occurring in multimedia presentations concern computer resolution settings, laptop battery conservation features and, of course, problems within PowerPoint. Here's some of the most common problems and a solution for each.

problem - there's an image on the laptop screen, but all I see on the projection screen is the company's logo

solution - activate the monitor's out port

Many laptop users don't know that their computers often require the user to manually export a signal to a projector through a series of keyboard commands. The procedure differs depending on the laptop, but it's typically a combination of the function ("Fn") key and the "F" key. Sometimes it also involves a key with a box-like icon that represents the monitor.

Part of the confusion stems from the fact that some laptops can automatically detect a connected projector and export a display signal. For this reason, you should connect and turn on your projector before powering up your laptop. This gives the laptop a chance to detect the projector, if it has that ability.

If your screen remains blank, then head for your user's manual to find the key combination that will create a toggle switch between internal (the laptop screen) and external (the projector or monitor). Some laptops also have a simultaneous setting.

Wading through a manual can be a drag, so a place to start is "external display" listing in the help index. You can also jump directly to the troubleshooting section or consult the laptop maker's website. 

problem - my screen went black in the middle of the presentation

solution - change the laptop's battery-conservation settings to "never"

Most laptops have a built-in piece of battery-conserving software that monitors the mouse and the keyboard and shuts off the screen (and eventually puts the whole computer into "standby" mode) if it senses there's no activity. If you use a remote during presentations, your laptop can be fooled into thinking nothing is happening and kill the show at the worst possible moment. If this happens, just move the mouse or strike any key, and the laptop should reactivate.

To prevent it from happening, adjust your computer's power-conservation settings. Windows users can access these by selecting Display from the Control Panel, then clicking on the "Energy-saving features" button at the bottom of the Screen Savers page.

problem - I get a pop-up menu every time I hit the right mouse button to reverse my slide 

solution - turn off pop-up menu in PowerPoint

To correct this wayward PowerPoint feature, go to the Tools pull down and click on Options and then View. After hitting the View tab, you should see a series of feature choices. The first box under Slide Show is "Pop up menu on right mouse click." Make sure this is not checked. This should solve the problem and let you reverse with ease.

problem - I upgraded my computer - now the image on my projector is blurry

solution - change your laptop's resolution setting to match your projector's resolution and turn off your laptop's display.

Mismatched resolutions are among the most vexing of laptop/projector compatibility issues that tech support people hear about and blurry images are a common manifestation of this problem.

Projectors and laptop screens both have "native" resolutions that represent the number of pixels they use to display images. Resolution is measured in terms of horizontal and vertical resolution; for example, an SVGA (800 x 600) screen uses 800 columns of pixels (arrayed horizontally) and 600 rows of pixels (arrayed vertically) to form its images.

Projectors and laptops work best together when they share the same true, or native, resolution. If the laptop's screen resolution matches the projector's native resolution, the projector can display the laptop's output without adjustment, because the laptop is already set up to display images with exactly the same number and arrangement of pixels as that found in the projector's LCD panels, DLP chips, or whatever imaging device the projector uses.

However, if the two resolutions don't match, the projector must scale (either compress or expand) the image coming from the laptop in order to display it. For instance, in an XGA (1024 x 768) to SVGA (800 x 600) conversion, the scaler takes the laptop's XGA image - made up of more than 786,000 pixels - and squeezes it to fit into the 480,000-pixel array used by the SVGA-resolution projector.

Most projectors have built-in scalers for this purpose - but depending on the quality of the scaling circuitry, the resulting images may not look very good. Unwanted byproducts of compression can include missing rows of pixels and image "artifacts," such as one effect that makes a lowercase "e" look like a lowercase "a."

Though vast improvements have been made in the digital-image scaling technologies used by some projector manufacturers, it's best to avoid using the projector's scaler whenever possible, either by using a high-quality external scaler or by changing your laptop's resolution.

changing a laptop's resolution
A quick way to change laptop resolution in Windows operating systems is to right-click on the desktop, then select Properties and the Settings tab, where you'll find the controls for screen resolution.

But don't count your pixels just yet - keep in mind that many laptops will continue to send their native resolution to the projector unless the laptop's screen is turned completely off. For example, a presenter might change the laptop's resolution from XGA to SVGA to mate with a SVGA projector. The laptop, using only the center of its internal display to show 800 x 600 pixels, would create a miniaturized onscreen image with a black box around it. However, in many cases, the computer will still be sending an XGA signal to the projector, because it detects the internal display. This would cause a worst-of-both-worlds scenario, with the projector compressing the laptop's already-miniaturized internal image.

You'll need to go back to the laptop manual to learn how to turn off the laptop's screen. This isn't a perfect solution (especially for a presenter with his back to the projection screen), but it will eliminate the image degradation caused by scaling.

problem - I don't know what cable goes with what

solution - spend a little quality time with your ports & cables

Mismatched or missing cables can be a significant source of problems. The solution to many compatibility problems is to get to know your cables. Look them over and make sure the pins on the cable and the ports match up. 

source: Scott D. Smith
, associate editor AV Avenue

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