Setting up your lighting can have a significant effect on the quality of your video. In a compressed video environment, the better the quality of the input video, the better the quality of your compressed video.
When RealProducer is compressing video which contains imperfections, it tries to reproduce those imperfections, spending less time on reproducing the important material in the frame.
So if colors are changing because of low light or there are other forms of noise, expect the final video to look badly.
Lighting is not too difficult to set up. You do not have to spend a great deal of money, you can purchase some "clip-on" lights for 5 dollars. You can adjust their light levels by installing lower wattage bulbs in different lights.
In the remainder of this document, we will describe a 3-light system used throughout television - if you are obsessed, you might start to notice the lighting on television from time to time.
If your light/space budget is too low for three lights. The fill light is probably the most important, followed by the key light and the back light.
In the side view, we can see the heights of the three lights and the rough distances and angles relative to the subject. As you are setting up the lights, look at the shadow cast by the nose and chin to get the shadows right. The goal is for there to be a noticeable shadow, but not a dark shadow. (Watch TV for a while and you will see this "shadow" everywhere.
The fill light is slightly lower than the key light. If you have "barn doors" (the little things that allow you to adjust where the light falls), you might try to keep the key light from falling on the background. In a low-budget three light setup, the fill light is used to light the background. By keeping the key light off the background and by virtue of the background being farther back than the subject, the background will have somewhat less light than the subject.
Remember that if you have only one light, use it in the "fill" position. Your shadows will be a little pronounced but you can light the subject and the background to some degree.
In the top view, we can see the angles from the center of the set. Whether the key is on the left or right is personal preference. The Fill is just on the opposite side. The back light can be directly in the back or offset slightly to one side or another. Some experts might tell you to go to the key side and others might like the fill side. But don't go too far from the center or you will lose your "halo" from one side.
In a one-light situation, you might want to move the fill a little closer to the center to keep the nose shadow as small as possible. By adjusting the position, you can keep the shadow off the background.
For best compression, choose a nice solid background with a minimum of color variation. The easiest is cloth, but the folds of the cloth cause color variation. Many studios use a royal blue (about the colors of the lights in the previous picture), but many colors work well. Another pretty background color is the color used by default on Windows-98. Make sure to choose a color which complements your skin tone. There should be some contrast between your skin color and the background but not too much contrast.
But don't get too obsessed with the background. If you want to shoot your video in the study with books in the background (lots of colors), go ahead - just make sure it is well lit so the colors don't wander as the camera struggles to adjust its levels to capture as much detail as possible.
Well, that is the quick light-tutorial. If you want to learn more, there are many books. Go to Amazon and search for "Video Lighting". You will find many books and perhaps a new hobby.