Slow in & Slow Out...
...refers to how the human body and most other objects need time to both accelerate and slow down. This being the case, an animation looks far more natural when it has a greater amount of drawings near the beginning and the end of a specific movement sequence, helping to elaborate upon the key poses, show fewer drawing within the middle of the movement sequence.
This principle can be used like anticipation in both a very subtle way, but also in a greatly elaborated sense. Anything from a character sitting and standing up, to another character skidding around a corner, where he would run in fast, slow down whilst skidding and maneuvering the corner then pick up speed again as he rounds the obstacle that is the corner and sets off in his desired direction.
This principle can be used like anticipation in both a very subtle way, but also in a greatly elaborated sense. Anything from a character sitting and standing up, to another character skidding around a corner, where he would run in fast, slow down whilst skidding and maneuvering the corner then pick up speed again as he rounds the obstacle that is the corner and sets off in his desired direction.
Classic Example:
The example below shows a classic clip from Tom & Jerry where slow in and slow out are used to great effect when the characters are chasing and being chased by each other, round conners. With the first example of rounding corners in this scene, you can see how the movements of Tom come in fast, then he dramatically slows in, whilst rounding the corner, changing direction, this helps to show his weight, volume and also the anticipation of the direction he next plans to move towards. After this he then increases speed again with a slow out and completes his turn of the corner.
Contemporary Example:
With this contemporary example slow in and slow out can be seen very quickly after the main 'Futurama' logo has arched across the screen, with the way the Planet Express ship flies in fast at the centre of the screen, slows for a brief second second in the mid-ground, slightly to the left, as it changes its direction of flight. We can then see how it picks up speed once more as it flies onward through the letter 'R' of the Futurama logo.
Written by Nick Crimmen