Echo--AE

This effect combines frames from many different times in a clip. It has a variety of uses, from a simple visual echo to streaking and smearing effects. This effect is visible only when there is motion in the clip. By default, any previously applied effects are ignored when you apply the Echo effect. If you do not want them ignored, create a virtual clip with other effects before applying the Echo effect.

Echo Time Specifies the time, in seconds, between echoes. Negative values create echoes from previous frames; positive values create echoes from upcoming frames.

Number of Echoes Specifies the number of frames to combine for the Echo effect. For example, if two echoes are specified, Echo will make a new image out of (current time), (current time + Echo Time), and (current time + 2 * Echo Time).

Starting Intensity Specifies the intensity, or brightness, of the starting frame in the echo sequence. For example, if this is set to 1, the first frame is combined at its full intensity. If this is set to 0.5, the first frame is combined at half intensity.

Decay Specifies the ratio of intensities of subsequent echoes. For example, if the decay is set to 0.5, the first echo will be half as bright as the Starting Intensity. The second echo will then be half that, or 0.25 times the Starting Intensity.

Echo Operator Specifies the operations to be performed between 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. Set the Starting Intensity to 1.0 per number of echoes and the Decay to 1.0 to blend the echoes equally. Maximum combines the echoes by taking the maximum pixel value from all the echoes. Minimum combines the echoes by taking the minimum pixel value from all the echoes. Screen emulates combining the echoes by sandwiching them optically. This is similar to Add, but it will not overload as quickly. Composite in Back uses the echoes' alpha channels to composite them back to front. Composite in Front uses the echoes' alpha channels to composite them front to back.

To incorporate a clip's motion into the Echo effect:

1 Set up your motion before applying the Echo effect.

2 Create a virtual clip of the clip with motion.

3 Drag the Echo effect to the virtual clip.

Note: Use a large Number of Echoes and a short Echo Time to get smooth streaking and smooth trail effects.

4 Set controls as needed.

Applying Effects > Video effects included with Premiere > Echo--AE