Legibility is a complex interrelationship of technique and technology.
Conversely, when the visuals are illegible, they interfere with the message. We are so accustomed to television, that someone could get the impression that all one needs to do is aim a camera at something and a perfect reproduction of that object or graphic will appear on the video screen. Unfortunately, that is not the case. To draw an analogy, the difference between life and television is similar to the difference between an ordinary photograph and a newspaper reproduction of that photograph. It's a clear difference.