The ultimate artistic objective of a digital composite is to take images from a variety of different sources and combine them in such a way that they appear to have been shot at the same time, under the same lighting condi-tions, with the same camera. To do all of this well, it is important to have a substantial understanding of the technology, because many of the obstacles that you will encounter are, in fact, not artistic obstacles. They stem from underlying technical issues that are not at all obvious to the casual observer but create problems in the shot.

  The designers of digital compositing software have tried mightily to create a software tool that hides the technology so that it can be used by artists, and to a large degree they have succeeded. However, no amount of artistic training will help you to pull a good matte from a bad bluescreen or smooth motion track jitter caused by grain content. Problems of this sort require an understanding of the underlying principles of the digital operations being used to create the shot and a library of techniques and different approaches to the problem.

  It takes three distinct bodies of knowledge to be a good digital effects artist: the art, the tools, and technique. The artistic knowledge is what allows you to know what it should look like in the fi rst place in order to achieve photo-realism. The knowledge of your tools is simply knowing how to operate your particular compositing software package. The third body of knowledge, which is technique, comes with experience. Eventually, you become a sea-soned veteran, to the point where you are seeing most problems for the second or third time and you know exactly what to do about them. The beginner, however, is continually confronting problems for the fi rst time and it takes time to run through all the bad solutions to get to the good ones. This book contains years of production experience.