Adobe Premiere Pro CS4 - Manual (Page 396)

390 USING ADOBE PREMIERE PRO CS4
Effects and transitions
Last updated 11/6/2011
Effect applied with threshold settings of 44 (left), 70 (center), and 200 (right)
Time effects
Echo effect
The Echo effect combines frames from different times in a clip. The Echo effect has a variety of uses, from a simple
visual echo to streaking and smearing effects. The results of this effect are visible only if the clip contains motion. By
default, any previously applied effects are ignored when you apply the Echo effect.
Original image (left), with low echo values (center), and with increased number of echoes (right)
Echo Time (seconds) The time, in seconds, between echoes. Negative values create echoes from previous frames;
positive values create echoes from upcoming frames.
Number of Echoes The number of echoes. For example, if the value is 2, the result is a combination of three frames:
the current time, the current time + Echo Time, and the current time + (2 x Echo Time).
Starting Intensity The opacity of the first image in the echo sequence.
Decay The ratio of the opacity of an echo to the opacity of the echo preceding it in the echo sequence. For example, if
Decay is 0.5, then the opacity of the first echo is half of the Starting Intensity; the second echo is half that, or one quarter
of the Starting Intensity.
Echo Operator The blending operation used to combine the echoes.
• Add Combines the echoes by adding their pixel values. If the starting intensity is too high, this mode can quickly
overload and produce streaks of white.
• Maximum Combines the echoes by taking the maximum pixel values from all of the echoes.
• Minimum Combines the echoes by taking the minimum pixel values from all of the echoes.
• Screen Emulates combining the echoes by sandwiching them optically. This setting is similar to Add, but it won’t
overload as quickly.