Graphics Reference
In-Depth Information
original Frame Rate (8 fps), while the third image is the clip running at four
times speed (96 fps).
In both examples, images from preceding and following frames are mixed
together at progressing or receding levels of opacity, creating the illusion of
slow motion (first example) or motion blur (third example).
Specialized visual effects plug-ins exist to take this Frame Blending even further
by incorporating proprietary motion interpolation and extrapolation algorithms
in the Frame Blending calculations. For Slow Motion effects they can actually
sense missing footage frames and create the additional in-between frames
needed to accurately recreate the footage frames that never really existed.
Examples of these plug-ins (and many other powerful enhancements) can be
found at www.ToolFarm.com.
Frame Blending - Mixing Different Frame Rate Footage
After Effects is a file format agnostic program allowing for the intermixing of
footage with dissimilar Frame Rates. You can use 25 fps footage in 29.97 fps
comps or vice versa, all with the assistance of Frame Blending.
In our Bouncing Ball project we used 24 fps footage in 24 fps comps. To
demonstrate Frame Rate intermixing, create a new Comp (Ctrl
N) with these
settings: 640
360 at 16 fps and a duration of 90 - yes, 16 fps.
Drag the
Bouncing Ball.mov
into the new Comp starting at frame 0, then run a
Preview. You should see a distinct stuttering to the ball's motion. Now activate
the Frame Blending for the layer and the Timeline, and run another Preview.
Now the motion is smoother, with every frame of the ball blending into the
Comp as it's previewed.
The only real physical drawback to activating Frame Blending is that it will slow
down your rendering, because cross-mixing multiple frames to make the blends
takes longer than simply dropping or duplicating frames here and there.
Interpret Footage - Frame Rate Settings
If you know for certain the Frame Rate needed for any clip you've imported,
you can permanently set a value for that clip in the Project Window using its
