How to apply an effect only for N time?

[EtoEgor]

Hello. How to apply an effect only for N time? For example I want to apply a blur effect for background image from 0 to 3 second, how to do this?

[dj.summitt]

Just keyframe the blur amount.

[Dave_LaRonde · Accepted solution]

Animate the blur.

Get the effect looking the way you want and set a keyframe (s).  Move the timeline cursor to the point just before you want the effect to end, make more keyframes.  Then move the timeline cursor to the point when you want the effect gone.  Just alter the effect value(s) until the effect is gone.