The possibilities for special effects are endless with digital technlogy.
Digital Special Effects
Wipes, split screens, luminance, and chroma keys make up the majority of special effects on the typical production switcher. There is another group of special effects called digital video effects (DVE). Digital technology will be discussed in greater detail later, but it is appropriate to describe some basic digital effects here. Most production switchers made today have digital video effects as a standard feature. Most DVE units have the following effects.
Compressions
Compressions are effects that change the entire aspect of the picture: the picture is made longer, or higher, or the entire picture is compressed into a smaller area. A common use of this technique is called chroma key tracking. With this effect the entire fill video is compressed to fit into the chroma key window. In the first figure, the entire launch has been compressed to fit into the smaller chroma key window. Many stations avoid the chroma key process entirely by compressing what would be the fill video and inserting it into a predetermined space in the program video.
Pushes
Another common digital effect is a push. A push, as you might expect, is where one video source pushes another off the screen.
Flips
There are several types of flips. In a page flip, the picture rotates around one edge of the screen as if you were turning the page of a book. Other flips can rotate around a central vertical or horizontal axis.
Rotations
Rotating cubes and spheres are two other digital effects, with video images making up the outer surfaces of these geometric shapes.
Other Special Effects
The array of possible digital effects is virtually limitless. Video images can be twisted, distorted, curled, and exploded into fragments and miraculously reassembled. In most situations, the effects are almost infinitesimal.
Many digital effects have become practical and affordable through the development of programmable digital switchers. These switchers can hold in their memories a sequence or combination of special effects and then recall the arrangement on a command from the user.
1. Chroma key tracking.
2. Pushes.