Focus on Technology: Audiovisual- A Quick-Start Guide to Video Conferencing Installation
Let’s assume you have just received the new video-conferencing-system-in-a-box that you ordered online from AcmeAV. The room it will be installed in is relatively small, seating 10 to 12 people. Before you start unpacking all those cables and reading that 765 page instruction manual, here is a list of tips and rules of thumb to help you ensure that your video conference installation will be more interactive and productive.
Rule number one: Don’t use video projection unless you have absolute control over room lighting. Flat panel displays such as LED backlit LCD or plasma work best. The display should be permanently wall mounted and oriented to the center of your conference table. Everyone seated at the table should have a clear line of sight to the images on the display. Mount the display on the wall so that the bottom of the image is no higher than 4 feet above the floor. Make sure the size of the display is appropriate for viewing by the most distant viewer at the table. (Divide the distance from the display to the farthest viewer by six. The result provides an acceptable display image height plus or minus a little; the width is controlled by the display format.)
Proper location of the camera will allow the viewers at the far end of the video conference to perceive that you are making eye-to-eye contact with them. It is preferable to locate the camera below the display at about 3 feet 6 inches above the floor. Remember that you want to convey the best possible image to those you communicate with.
If your conference table is smaller than 8 feet, a multi-element “pod” type microphone should work well. Once the table gets larger than 10 feet, it is recommended that individual microphones with a cardioid pick up pattern be provided for every two people seated at the table. Locate each microphone about 2 feet back from the edge of the table and make sure that the microphone’s pick up pattern is oriented towards the participants. Proper mixing of the microphones should be accomplished using a digital signal processor (DSP). If the DSP has on-board echo cancellation, be sure to disable the echo cancellation that is built into your video CODEC.
Room Lighting Never use exterior sunlight as illumination for your video-conference. It is best to use fluorescent lighting with a color temperature of approximately 3200 Kelvin. Avoid using directional fixtures that illuminate participants from directly above. This will cause unwanted shadowing on faces. If possible, install lighting fixtures that angle the light away from the video display at a 45 degree angle to the participants’ faces. Proper illumination of walls behind the video conference participants is also important. Make sure this wall is evenly illuminated and only slightly darker than the main source of illumination.
Avoid using ceiling mounted loudspeakers for the incoming sound from the far end of the conference. It is best to locate loudspeakers above or to the left and right of the video display. This helps reinforce the illusion that the sound is more localized to the people speaking from the far end. In summary, there are many factors that contribute to a successful video conference installation, far more than could be contained in a single newsletter article. If you implement the items listed above, you have already eliminated 80% of the biggest mistakes often made by the novice do-it-yourself video conference installer.