Grain Removal

Grain Removal

Removing grain, or sharpening an image in general, is an
entirely different process from adding grain. On a wellshot
production, you’ll rarely have a reason to reach for
the Remove Grain tool.
If you do, the reason for doing so may be unique to your
particular footage. In such cases, you may very well fi nd
that leaving Remove Grain at the default settings gives you
a satisfactory result. If not, check into the Fine Tuning and
Unsharp Mask settings to adjust it.

Remove Grain is often best employed stealthily—not necessarily
across the entire frame , or as part of
a series of effects. It is a reasonably sophisticated solution
(compared with the current alternatives) that can really
help in seemingly hopeless situations; this book’s technical
editor reports having used it extensively on a feature fi lm
in which the aging lead actor needed a lot of “aesthetic”
facial work done (removing wrinkles and so on).

Use Noise as Grain

Prior to the addition of Add Grain and Match Grain
to version 6.5 Professional, the typical way to
generate grain was to use the Noise effect. The
main advantage of the Noise effect over Match
Grain is that it renders about 20 times faster. However,
After Effects doesn’t make it easy for you to
separate the effect channel by channel, and scaling
requires a separate effect (or precomping).
You can employ three solid layers, with three
effects applied to each layer: Shift Channels,
Noise, and Transform. You use Shift Channels
to set each solid to red, green, or blue, respectively,
set Blending Modes to Add, and set their Opacity
very low (well below 10%, adjusting as needed).
Next, set the amount of noise and scale it via the
Transform effect.
If the grain is meant to affect a set of foreground
layers only, hold them out from the background
plate either via precomping or track mattes. If this
sounds complicated, it is, which is why Match
Grain is preferable unless the rendering time is
really killer.