Page 178 - Mediapedia Mobile

PART I1I SHARING YOUR WORK
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TIMING AND RHYTHM
Time code is a precision standard by which time is measured in professional media. Consumer-level slide show applications are abandoning the use of time code in favor of less-accurate measures of seconds. This is not a good thing. If your slide show program tracks time only via seconds, not parts of seconds, you’ll have to rely on trial and error instead of frame-accurate markers to sync images and audio.
Each image in a slide show occupies a precise amount of time while it’s displayed. The patterns that aggre- gate from these timings can form repeating rhythms.
Choosing and ordering images is about half the art of mak- ing a slide show. The other half is setting it into motion. And motion takes place in time.
Pacing, tempo, and visual rhythm become powerful fac- tors in shaping your audience’s experience. Most slide show engines come with tools that allow you to control how long each slide is held on the screen. Even if you are conducting a when-clicked show, it is important to remain aware of how the rhythm of the slide sequence changes your perception.
Time code is used in making video and audio. It con- sists of a sequence of numeric codes generated by the computer. In the example here, the first pair of digits
is for minutes, the second for seconds, and third pair is for thirtieths of seconds. When time code is used to record over extended periods of time, the gauge adds two more digits at the beginning, to record hours.
Whether a slide show is automatic or when-clicked, its audience eagerly awaits the flow of a well-paced presenta- tion. It should vary: slow and measured to fast and exciting.
measuring time
Duration is the amount of time a visual image or audio event is held within a time-based medium. Duration affects perception.
Minutes, seconds, and frames are the standard measures within time-based media.
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CHAPTER 5: SLIDE SHOWS
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When slide shows are improvised, it’s up to the presenter to control how long each image is projected. This is no easy feat, and many ponderous shows result from those who are unpracticed in the art of controlling the velocity of a presen- tation.
A single image is certainly readable if it is held for one sec- ond. Viewers automatically adjust their perceptual thresh- old so that within a fast barrage of images their eyes can discern a flashed image that is held for ten video frames (a third of a second) or even less. But if you put the same ten-frame shot amid a stately procession of three-second images, the viewers will miss it.
Inside every computer is a clock. It is always turned on and never runs fast or slow. Many media forms hook into this foundation of measured, reliable time.
Viewers will quickly pick up on an established tempo. Humans have an inner clock that seeks out repeated patterns within time. We expect breaks or changes in an established rhythm to signify or accompany changes in meaning. Make full use of this technique in your slide shows.
duration