Film grain
Fine noise over the final image, instead of a spotless finish.
The Film grain section adds fine noise to every pixel of the finished image, imitating film grain. The spotless surface of a render is one of the things that give away that an image is synthetic, and a little grain hides it.
Controls
- Strength: From 0 to 1. The noise is the same across the image, as bright as it is dark, applied after tone mapping.
How to use it
Between 0.1 and 0.25 the grain shows up close and disappears at a distance, which is the effect you want. The image above uses a high value on purpose, so the noise survives in a thumbnail.
Grain also hides the banding that shows up in smooth gradients, such as a sky or a large wall lit from the side. This is camera grain, not computation noise: for the noise that comes from rays, see ambient occlusion and global illumination.