Film grain is one of those things that can really help sell your composite or graphics (or help reduce banding). But it can be a pain (and slow) to render on top of an already complicated effects stack. To make this much easier, here’s what I do in AE:
Grain

  1. Create a one second comp at the highest fps and largest size you’ll use—for me, that’s 2k (2048×1152, 60fps for safety).
  2. Place a 50% gray solid and add the Add Grain effect. (Effect>Noise & Grain>Add Grain)
  3. Chose your preset. I typically like to use Kodak Vision 320T for graphics1, but it will vary for composites as you’ll want to try and match camera grain/noise. You may also want to use the Match Grain effect instead.
  4. Render out an uncompressed image sequence or QuickTime.
  5. Import the render and change the frame rate to match your project (if necessary). Also set the looping to something that will cover your longer comps. I work in broadcast, so it’s mostly 15, 30, or 60. All of this is done under File>Interpret Footage>Main…
  6. When it’s needed, place this layer above your graphics, set the transfer mode to Overlay, and adjust opacity to vary the strength of the grain, or add a curves effect for more or less contrast.

By using such a large frame size for the grain render, you can use it on any smaller size comp by just keeping the scaling to 100%. I actually have a few different types (and sizes) of grain, and even just plain noise in my collection. The differences are subtle, but they make a difference.

You’ll now have a quick way to add grain to pretty much any size comp at any frame rate that won’t bog down your renders.

[box type=”info”]Note that using too much grain can really mess with compression of your final piece. Most compression works by looking for areas of the image with the most detail and attempting to retain that detail. By adding grain, you can confuse the compression algorithms into thinking there’s detail in areas where there really is none; other areas of high detail might suffer.[/box]

  1. This really has no technical reason behind it. It’s just my film school preferences coming into play. []