Contrast Ratio for Cameras
In video and film work it is important to understand what sort of contrast ratio your camera is able to reproduce. A high contrast ratio means that brighter and darker areas of the image will be recorded with more accuracy and apparent detail.
Most people don't need to know the actual specifications but video makers need to be aware that video has a relatively low contrast ratio. If an image includes extreme light and dark, the camera will struggle to reproduce both. Bright areas will appear over-exposed and dark areas will appear "crushed" (all black, lacking detail).
The example on the right illustrates a common problem for sports coverage in stadiums — the difference between the sunlit areas and the shadows is significant.
The best way to minimize problems with contrast ratio is to avoid having very bright and very dark objects in frame at the same time. When dealing with human subjects it makes sense to avoid white and black clothing. Also, be wary of caps and sunglasses in strong light — they can create terrible over-contrast on the face.
If you can't alter the framing, either add lighting to the dark areas or filter the bright areas.
When all else fails, the standard approach is to expose for the subject. If some parts of the picture are too bright or too dark it's not the end of the world — people are used to seeing this.
Note: Film cameras generally perform better than video, but still do not reproduce the same range that the human eye would see.
See also: Contrast Ratio, Camera Iris, Lighting with Background Windows, TV/Monitor Contrast Ratio