Touring the Interface with a Basic Composite - Nuke 101: Professional Compositing and Visual Effects - page 80

Tip
If, unlike my tree, your tree is really messy, it will be hard for you
to understand the flow of information and therefore read your tree.
Sure, this is a simple tree. But if it were bigger, and you saved it
and went back to it over the weekend, things might start to no longer
make sense. Keeping an organized tree is always a good idea.
Frame42,whichyouareonatthemoment,isthelastframeofbrightlightingyou
havebeforethebackgroundstartstodarken.Thiswillbethelocationofyourfirst
keyframe, to lock the brightness of the doll to the current brightness level.
3. In Grade2's Properties panel, click the Gain property's Animation menu and
choose Set Key ( FIGURE 2.52 ).