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I'm using After Effects CS6, and I'm deliberately trying to recreate the look of a cheap camcorder. I want that stereotypical red "REC" text and big red dot in a corner of the screen, and I want it to blink off and on. I want the "ons" and "offs" spaced one second apart, like so:

ON ==[one second]=> OFF ==[one second]=> ON ==[one second]=> OFF

And so forth. However, animating this by hand is a huge pain. How can I automate this animation? Would an expression work, or is there a way to tell After Effects to loop certain keyframes?

Thank you.

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up vote 2 down vote accepted

This can be done easily with a mixture of time remapping and an expresison. Simply precomp the text animated as once on, once off (keyed out manually), then drop it into your main comp and apply the following expression:


Then, just extend the composition for as long as you would like it to loop.

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That seemed to do it. I hate to be a bother, but could you please tell me what specifically the terms in that expression mean, for my future reference? – Tortilla Aug 9 '12 at 1:06
There is a really good explanation of all the loop expressions (and other expressions) and their uses in this Adobe help article:… – Oliver G Aug 9 '12 at 9:30
Excellent, thank you very much! – Tortilla Aug 9 '12 at 18:24

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