Videoconferencing Tips

Introduction

I put together the following videoconferencing tips assuming a PC-based videoconferencing system operating over a low-bit-rate connection. However, most of it applies to any form of videoconferencing or teleconferencing, regardless of what system or connection one uses. Please email me with a tip that you'd like to include. I'll list you as a contributor unless you tell me otherwise.

Video

The better the camera, the better you'll look to the other party. There is a noticeable difference.

• With current technology, your home camcorder will provide the best picture. If it automatically turns itself off after a few minutes, make sure there is no tape in it. If it still turns off, try leaving the tape door open. Next, you'll need a capture card to use your camcorder. Hauppauge, ATI, and Winnov make good capture cards for as little as US$99.
• The next best quality comes with a camera that is made to use with computers. Philips makes a good, inexpensive camera like this that can be had for about US$200. Like a camcorder, these cameras need a capture card.
• The next best quality after camcorder and computer cameras that require a capture card are USB cameras. If you have a relatively new computer, there is a good chance that you have a USB port. Just plug the USB camera into the…you guessed it…USB port. No capture card needed.
• The lowest quality cameras are parallel-port cameras such as those made by Connectix and Vivitar. Their image quality is not as good (image not as sharp and low frame rate), but they are less expensive and much easier to install--you just plug them into the parallel port on the back of your computer.

It's best to use a camera that does not adjust the image automatically, e.g., focus and brightness. This will lower your frame rate or, believe it or not, lower the spatial quality of your transmitted image. This is because there is all of a sudden a fair amount of difference from one second to the next in the entire image, thus making the scene more complex, and require more information about the image to be sent to the other side.

If present, use the controls for your camera to lower contrast as much as possible without compromising overall quality. More contrast means more information to send which means slower frame rates. If you reduce the contrast, increasing the brightness a little may help.

Wear neutral, solid colors.

Likewise, have a simple, static background (nobody walking behind you in the hall, move the clock out of the scene, and no windows, please) in neutral, solid colors.

A user of AudioVision sent me this: "I've found that a darker plain background produces less data to transmit than a lighter one. With a black background, my VMail files on AudioVision are 1/3 the size as with a white background." For videoconferencing, this should translate into a higher frame rate and/or a crisper image.

Be natural, but try to minimize movement.

Have plenty of light on the face of the person speaking. If you have too much light from the back of the room, you'll appear as a silhouette. Too much from the ceiling and your eyes will be black.

Try to eliminate shadows. A shadow of your hand, for example, to a VC system is like another hand, so the VC system has to do twice as much motion handling as it would normally do, typically reducing the frame rates with a subsequent reduction in perceived video quality.

Try to remove spot sources of light. Modern rooms tend to have downlighters which cause hot spots. These affect the camera iris settings on automatic systems and thus reduce the image quality.

If you can also ensure that the table around which the participants sit is light in color, the lighting will be reflected up into the participants faces from the table surface, reducing the shadow effect.

Position the camera as close as possible to the image on the screen of the other party. This results in near eye contact because you will most likely be looking at the other party's image. Eye contact is very important for interpersonal communication. If the camera cannot be place close to the image, the speaker should consider and experiment with facing and talking into the camera, not looking at the other party's image. Otherwise, you get two people watching each other look at their computer screens, at least in the case of PC-based videoconferencing.

Don't get too close to the camera. They typically have wide angle lenses that distort the face if you're too close. Again, experiment with the system in local loopback mode to see what looks best before you go online.

Make sure the camera is mounted solidly and will not shake even minutely during the call. Besides the other party seeing the possibly distracting movement, shaking drops the quality of the image. Typically, the frame rate drops.

Audio

As with video, use a good microphone and speakers. The cheap microphone that came with the software you bought at a local computer store may not be good enough. A good one shouldn't cost a great deal, though. You'll get the best results with a headset or handset because neither you or your videoconferencing system has to worry about echo. A really good headset (combined mike and speaker) should cost around $100. InterActive makes a telephone with cradle for videoconferencing. It costs $99. You can even use a regular telephone with Quicknet Technologies' Internet PhoneJACK. I've never used it, but it looks like a pretty slick device. Telephones just seem more natural to me and provide the privacy that other solutions can't.

I've tried a couple of other handsets that I didn't like. One had a cradle, but its handset was unusually short--the mouthpiece only came down to my cheek. Real uncomfortable. Another handset was long enough, but the sound quality was poor. One that I can recommend, however, is the INT100CS Internet Telephone Handset, manufactured by Conair under license from Riparius Ventures, Inc. The handset is normal-sized (for my big head, at least) and comfortable. The sound quality is excellent. But the coolest thing about it is the phone cord. It has an RJ11 modular connector on one end that plugs into the handset and connectors on the other end for the microphone and speaker jacks on your sound card. It turns out that the handset is just a normal telephone handset, and one can use any regular telephone handset that has a modular RJ11 jack with this cord. Cool! The cord also has a pass-through connector so that you can continue to use your external speakers with the handset. This is a nice, unexpected feature, but it has been my experience that most PC speakers are always amplified and should be plugged into the LINE OUT jack, whereas the (unamplified) handset should be plugged into the SPKR OUT jack. If I plug the cord into the LINE OUT jack and my amplified speakers into the pass-through connector, I get poor audio out of the handset. If I do the opposite, I get poor audio out of the speakers. Ideally, the user has either unamplified speakers or speakers that continue to operate as unamplified speakers, like the handset, when the power is turned off to them. I have speakers like this on one of my PCs. Then the handset could be plugged into the SPKR OUT jack and the speakers into the pass-through, and we'd have good audio all around.

Don't "eat the mike" by placing it closer to your mouth than it was designed for. Eating the mike distorts your voice. If you are doing it because the other party can't hear you, back off the mike and turn up the level of the mike and/or have the other party turn up the volume of his or her speakers.

Videoconferencing systems typically don't let the speaker hear his or her own voice so the speaker cannot judge how loud he or she should be speaking. However, telephones have always done this. If you doubt me, pick up the phone right now and check. Before making those important videoconferencing calls, experiment to see how close you should be to your microphone so that the other party hears you clearly, and regardless of whether you have a microphone, headset, or handset, use the controls of your system to adjust the microphone and speaker levels. Make sure at the beginning of every call that the other party can hear you clearly. If you can't tell, just ask them.

Analogous to video, it's best to have no background noise.

Since there may be some audio (and video) delay, depending on your transmission media, try even harder than in normal in-person or telephone conversations not to dominate the conversation. Be sensitive to the other party wanting to speak, even by inviting them to do so periodically.

Practical solutions to minimize echo include soft furnishings to dampen the audio paths. Glass is particularly bad for audio reflections, so room curtains can help.

For better PC sound quality, make sure your speakers are plugged into the correct jack on your sound card. There are usually two jacks, labeled something like LINE OUT and SPKR OUT, as in SPeaKeR OUT. Speaker enclosures often contain more than speakers. They contain a little amplifier that you can turn on and off. (You can usually tell that the amplifier is on because a little red light is illuminated.) Note that some speakers only work when their amplifier is turned on. When your speakers are turned on, you must plug them into the LINE OUT jack. When your speakers are turned off, assuming you have the kind that will continue to function as unamplified speakers, you must plug them into the SPKR OUT jack. Failure to abide by these instructions results in poor audio quality.

Many people make the mistake of turning their speakers "on" because they think they won't work if they are turned "off" (on the surface, this makes sense) and then incorrectly have them plugged into the SPKR OUT jack because, after all, they are speakers, aren't they? Check your PC right now. This could be an easy way to significantly improve your sound quality at no cost. By the way, I usually turn my speakers "off" and plug them into the SPKR OUT jack. There is no point in wasting electricity on the redundant amplifier in the speaker enclosure, is there? You see, the SPKR OUT jack is the output of a little amplifier built right onto the sound card; the LINE OUT jack is the direct output of the digital-to-analogue converter circuit which provides a raw, unamplified signal that yearns to be plugged into a speaker that will amplify it--a speaker that is turned "on."

Contributors

Howard Rubinstein, Doug Domeny, Phil Sewell