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Volume 2 Issue 9October 1998
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Lighting a Videoconferencing Environment
Part One introduced basic concepts of lighting, including different lighting types, characteristics of light, and color temperature.
Existing office or classroom lighting is not always well adapted to videoconferencing needs, as there are special considerations necessary to ensure a high quality picture. Modifications to existing lighting may solve some of the problems, and specialized lighting systems are available for a custom solution.
Once a particular type of lighting has been selected, the next consideration involves mounting the fixtures. Different types of lighting are available in many fixture styles, and can generally be placed into two categories.
Mounting Lights
Lighting attached to the ceiling
There has been no distinct crossover in the lighting industry (for options under $50,000) between the functionality of the studio fixture and the aesthetics of architectural lighting. This is the core of the problem of aesthetics versus functionality that faces videoconferencing room design.
The industry has not developed an angled fixture that will sit flush into an acoustic ceiling grid. Even if such a fixture existed, there would still be problems with the ceiling panel's position in comparison to the participants at different locations around a table.
Specialized videoconferencing lights are available, and may be mounted to hang directly from any standard drop-ceiling grid.
Lighting attached to a tripod stand
While a tripod mount offers more versatility than a ceiling mount, it may not be not sufficient as a permanent solution, as the fixtures will be underfoot and in the way of conference room traffic. Cords running across the floor can also pose a hazard.
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White-Balance and Color Control
The way the camera evaluates the average lightness of an image on the screen, the White-Balance function of the system, is a critical factor in understanding the best way to fix a poor screen image.
At the default setting, the system takes an average of the varying tones of color in the shot and then compensates for a certain average percentage of gray (around 20 percent).
Thus, if a shot contains a high percentage of white or lighter tones, the system will attempt to darken the overall shot, making the darker sections even darker. This means that the participant’s face is often evaluated as one of the darkest things in the shot, and is darkened more so that participants on the other end can better see your wall without all the hot-spots or white-flares.
In many cases, a subject sitting in front of light colored walls will quickly loose even more facial details and the unflattering shadows will actually increase. This effect is the cause of dark and undefined facial profiles in the midst of washed out white tones and hot-spots. People with darker skin tones are especially affected.
There is a difference between color tone and brightness. For example, a subject in a dark blue shirt can be illuminated with as much non-directional overhead light as possible, but this brightness will only force the camera to compensate further for the white walls around the subject. In most cases, the white-balance is reading the color tone rather than the brightness of the scene.
To illuminate a scene properly, the face of the person conferencing should always be the lightest color tone on screen. If possible, remove any white from the scene. In most cases this will include changing the color of your walls to a darker shade. Shades of blue work the best.
Participants should also be reminded to dress appropriately. Solid colors are better than complex patterns, and dark or neutral colors are best. Stripes or busy patterns will cause the camera's focus to oscillate and destroy picture clarity.
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Inside Your Camera and the Auto-Iris
Once the lighter color tones in the room are removed, don't be afraid to adjust the brightness and contrast controls. Remember that the factory defaults assume the worst of conditions. Without the danger of white creating flare in your shot, try opening up the iris stop or increasing the brightness of the camera.
Furniture and Accessory Placement
The Table - Non-white, matte, non-reflective finishes are best. When placing a table, remember to take into consideration that lighting is adjusted in relation to the participant's position at the table. If a larger or smaller table is used later, there is a good chance the lighting will need to be altered as well.
Windows - If there are windows in the room, position the participants so that they face the window, and have a curtain or blinds installed, in order to control the environment.
The Walls - Make sure that the wall or background color is of a fairly dark shade. Royal blue or robins-egg blue will produce the most pleasing results. However, any darker shade will be a great improvement. Angle pictures or awards downward to avoid glare.
Common Mistakes in a Distance Education Environment
- A large white grease board behind the professor that causes total overcompensation of the auto-iris and hot spots.
- Overpowering an LCD projection with light that is supposed to be on the instructor, thereby failing to illuminate the speaker effectively and also washing out the projected image.
Common Mistakes in a Corporate Environment
- The videoconferencing room is the corner office, and has two glass walls that get fantastic western exposure. The view is wasted because of the heavy curtains that have to be installed.
- The table is bright enough to see the participant’s reflection.
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Checklist for a Videoconferencing Room
Videoconferencing room(s) will have a different look and feel as a result of the special environmental requirements necessary for a quality broadcast. Remember that the purpose of the room is to impress the people on the other end of the videoconference.
Lighting should be 40 foot candles, from a soft directional light source at a 45 degree angle.
Make sure the wall or background color is of a darker shade. Royal blue or robins egg blue will produce the most pleasing results. However, any darker shade will be a great improvement.
Remove all white from the viewable area.
If there are windows in the room, position the participants so that they face the window, and have a curtain or blinds installed, in order to control the environment.
Choose a table top that is non-reflective, preferably of a darker shade.
Optimize the brightness and auto-iris controls of the camera to best suit the rooms needs.
Use a wall accent or a string of track fixtures aimed at the walls to produce a wall-wash effect that will help give contrast to the shot and give a greater three dimensional perspective to the participants.
Additionally, incorporating room accents, such as small trees, signage, or different paint colors as trim or a two-tone wall, will add visual interest to your setting.
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Color Effects
Since color has an effect on the emotions of the audience, correct color choices in the background can have a tremendous effect on the emotions of the audience, as well as on the success of the presentation. Keep in mind that the image(s) themselves have power symbolic meanings as well.
The effects of specific backgrounds include cultural reactions to what certain colors mean or represent. The psychology behind the color background goes beyond our general references and into a deeper significance.
Keep in mind that society agrees on associations for colors based on appearances or cultural habits (as in green being associated with money in the American culture). However, these color associations are tied to a deeper, more emotional reference that each color signifies. There is more to color than mere association or attachment.
The color of the foreground elements does not significantly affect the general feeling the audience gets. It is the background color choice that determines the emotional response from the audience.
All people, regardless of culture, share a similarity of emotions. Happiness, sadness, excitement, anxiety, desire, passion, etc. The ability to tap into these emotions using correct color choices can increase the effectiveness of the presentation.
Conversely, incorrect color choices may lead to an emotional response from the audience that is different than expected.
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