Adjustment Layers

Adjustment Layers

An adjustment layer is itself invisible, but its effects are
applied to all layers below it. It is a fundamentally simple
feature with many uses. To create one, context-click in an
empty area of the Timeline, and choose New > Adjustment
Layer (Ctrl+Alt+Y/Command+Option+Y).

Adjustment layers allow you to apply effects to an entire
composition without precomping it. That by itself is pretty
cool, but there’s more:
. Move the adjustment layer down the stack and layers
above it are unaffected.
. Change its timing and the effects appear only on
frames within the adjustment layer’s In/Out points.
. Time any effect in an adjustment layer by setting layer
In/Out points.
. Use Opacity to attenuate the amount effects are applied.
Many effects do not themselves include so direct a control,
even when it makes perfect sense to “dial it back
50%,” which you can do by setting Opacity to 50%.
. Apply a matte to an adjustment layer to apply an effect
to one area of the image.
. Add a blending mode and the adjustment layer is
fi rst applied and then blended back into the result.
It’s a good idea 99% of the time to make sure that an
adjustment layer remains 2D and at the size and length of
the comp, as when applied; it’s rare that you would ever
want to transform an adjustment layer in 2D or 3D, but it
is possible, so don’t let it happen by accident. If you
enlarge the composition, you must resize the adjustment
layers as well.