https://i.ytimg.com/vi/Sfap4BwG5Ac/hqdefault.jpg

This very simple and quick tip will show you how to make noise look a lot less noticable in animations rendered with Cycles. You’ll see how to emulate natural film grain using the “seed value”, thereby reducing your needed samples (and as a result gain shorter render time) for the animation to look noise-free.
The tip consists solely of animating the “seed value”.

Take a look over here for a side-by-side comparison of static and dynamic seed:

Blender: http://www.blender.org/

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