Animating Added Or Matched Grain; Tweaking Controls For Matching And Adding Grain - Adobe AFTER EFFECTS 7.0 Manual

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To define the midpoint of the image's tonal range for grain application purposes, adjust the Midpoint slider. By
default, this is centered at 0.5, which represents the middle of the range of pixel values, 127 for 8-bit images and
16384 in 16-bit images.
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For even finer control, use the Channel Balance controls to adjust the grain in the shadow, midtone, and highlight
areas independently for each channel.

Animating added or matched grain

By default, the grain or noise generated by the Add Grain and Match Grain effects moves at the same speed as your
source material, to accurately simulate realistic noise. Slowing down the noise processes may be useful for aesthetic
effect or to keep the added noise from buzzing and drawing attention to itself. These effects have an internal
randomizer that changes the positions of the noise pixels between frames. But you can also change the appearance
of the noise between layers on the same frame while keeping every other parameter constant.
You can use the Animation controls group for the Add Grain or Match Grain effect to do the following:
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To determine the frame rate of the added grain, as a multiple of the destination frame rate, adjust the Animation
Speed value in the Animation controls group in the Effect Controls panel. At the default 1, the noise moves at the
same rate as your frames. At zero, the noise is stationary over time.
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To use interpolation to create smooth transitions between the generated noise frames, select Animate Smoothly.
This control matters only when Animation Speed is less than 1.
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To change the appearance of the noise between layers on the same frame, adjust the Random Seed value. Each
Random Seed value represents one of 100 possible variations in the appearance; changing the value doesn't make
the results more or less random.

Tweaking controls for matching and adding grain

The Match Grain and Add Grain effects share a group of Tweaking controls. You can use these controls to modify
the intensity and size of the noise and to introduce a blur, all of which can be done across the three channels or
individually for each channel. You can also change the aspect ratio of the applied grain.
Note: The values of the Tweaking controls are relative to the noise sampled in the source layer: a value of 1.0 leaves that
property of the source noise unchanged, while higher and lower values alter the applied noise.
Adjust any of the following controls in the Tweaking controls group:
Controls the amount of variation in brightness and color strength between pixels in the generated noise,
Intensity
which determines the visibility of the noise. Increasing the value does not change the position or size of each grain
but makes the grain appear to pop more; lower values give a more subtle muted appearance.
Controls the contrast between pixels in the generated noise separately for each channel. For
Channel Intensities
example, you may want to add more grain to the blue channel to emulate film.
Adjusts the size of the generated grain in pixels.
Size
Adjusts the size of the generated grain in pixels independently for each channel.
Channel Size
Sets the amount of softness in the grain.
Softness
Controls the ratio of the width of the generated grain over a constant height of 1; this is useful for
Aspect Ratio
emulating the effect of anamorphic lenses or for aesthetic effects. A value higher than 1 stretches the grain horizon-
tally; values smaller than 1 squash it horizontally.
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User Guide