Color Correction - Nuke 101: Professional Compositing and Visual Effects - page 160

6. Bring the value of Add2's value property to around 0.1.
You can see, as in FIGURE 4.11 , that the Add operation changes the whole dy-
namic range of your graph, and therefore, for any image.
Figure 4.11. The whole graph is raised or lowered in unison.