Game Development Reference
Figure 6.55 Dragging the point that represents 50% gray upwards lightens the midtones.
because by default, black is mapped to black, white is mapped
to white, 50% gray is mapped to 50% gray, and so on. However, if
we were to click 50% gray (the point in the center of the graph),
and drag it upwards slightly, it would make the midtones lighter
(Fig. 6.55 ).
Remember that the left edge represents the new (output) lumi-
nance, beginning with the dark tones at the bottom to the bright
tones at the top. So, when we move a point up, we brighten those
values, and when we drag a point down, we darken them.
I'm going to click the Reset button at the top of the effect to get
our curve back to the way it was. What I really want to do to this
image is to darken the shadow areas and brighten the highlights.
To do this, I will use such a common method that it has its own
name—the S-curve. The name comes from the way the curve
looks when we're done editing it. To create the S-curve, click on
the line over the input shadow area (on the left hand side of the
curve), and drag downwards. This will darken the shadows. Next,
click on the line over the input highlights area (on the right hand
side of the curve) and drag upwards. This will brighten the high-
lights. The results in the Effect Controls panel now look like an
S-curve, and the contrast has increased dramatically in our image
(Fig. 6.56 ).
The real benefi t of Curves is that we have this entire curve
available for adjustment, not just three points. If there was a pre-
cise shade of gray that you wanted to have, you could make it
brighter or darker without adjusting other shades. This is much