Adobe 65021048 User Guide - Page 354

ADOBE PREMIERE PRO CS3 348 User Guide • 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 information 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