Defining length of time effect is seen

[Dave Johnson]

The simplest way is to trim the layer to length you want … put the playhead at the inpoint you want and hit “ALT [” on your keyboard, then put the playhead at the outpoint and hit “ALT ]”.

You can also keyframe effect settings for a less abrupt start and stop, but I don’t recall off-hand which parameters to keyframe on the lightning effect to get it to go from and to nothing. Even if you do that, it’s still best to trim the layer to the needed length.

[Todd Kopriva]

Another way to apply an effect to only a specified duration is to apply the effect to an adjustment layer and then trim the adjustment layer to that duration.

Follow the link to Andrew Kramer’s video tutorial on this page for an example.

———————————————————————————————————
Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
———————————————————————————————————

[John Perez]

Yes, these are great solutions, and yes my 9 yr old loves the advanced lightning effect. And yes, and adjustment layer just like in Photoshop. I’m very new to AE CS4. I am well-versed in photoshop so I need to think of my Photoshop solutions as I learn AE. Thanks so much, guys…

As always thanks so much to you guys…Johnny In Orlando

[Dave Johnson]

I should’ve specified that the layer I suggested trimming should be an adjustment layer since it would rarely be practical to apply an effect like lightning directly to a footage layer.

And, you’re exactly right that thinking with your Photoshop brain will give you a huge head start in AE … especially since the two seem to converge and overlap more and more with each new version.

BTW, I take exception to the idea that only kids like lightning effects … I’m well beyond 9 and I kinda like lightning effects … perhaps just because I live in the lightning capital with sports teams like “The Lightning”, “The Storm”, etc., but I still like them ;~)