Adobe Premiere Pro CS3 - Manual (Page 354)

ADOBE PREMIERE PRO CS3
User Guide
348
• Screen Emulates combining the echoes by sandwiching them optically. This setting is similar to Add, but it won’t
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.
• Blend Averages the echoes.
Posterize Time effect
The Posterize Time effect locks a clip to a specific frame rate. Posterize Time is useful on its own as a special effect,
but it also has more subtle uses. For example, 60-field video footage can be locked to 24 fps (and then field rendered
at 60 fields per second) to give a film-like look. This effect is sometimes called Strobe in hardware devices.
Animating the value of the Frame Rate slider can give unpredictable results. For this reason, the only interpolation
method allowed for the frame rate is Hold.
Time Warp effect
Time Warp effect
The Time Warp effect gives you precise control over a wide range of parameters when changing the playback speed
of a layer, including interpolation methods, motion blur, and source cropping to eliminate unwanted artifacts. Since
Time Warp affects video only, it is usually best to unlink video from audio before applying it to a clip. Reducing the
speed of a clip with Time Warp does not extend the clip’s duration, but instead makes it end on an earlier frame.
You can nevertheless retrim the clip, retaining the Time Warp effect, up to the clip’s full duration. However, during
trimming, the monitors will show the In and Out points of the host clip unaffected by Time Warp. For example, the
end point you might see in the Program Monitor while trimming will not be the end point of the clip when you
preview it with the effect applied. Also, warning bars will not appear on the clip in the Timeline when you trim past
the last frame of available media. Precise trimming of a clip with the Time Warp effect can be tricky. For more infor-
mation on using Time Warp, watch the
online training video on the Total Training website.
Method options
These options determine how interpolated frames are generated:
Whole Frames Duplicates the last frame shown.
Frame Mix Creates a new frame by blending existing frames.
Pixel Motion Creates a new frame by analyzing the pixel movement in nearby frames and creating motion vectors.
Adjust Time By controls
Choose Speed to specify a time adjustment as a percentage. Choose Source Frame to specify a time adjustment by
identifying which source frame is to play at which time. If you choose Source Frame for Adjust Time By, then you
must animate the Source Frame property to do anything other than freeze on one frame.
April 1, 2008