Graphics Reference
In-Depth Information
you can ignore all of the warnings about clipping either end of the signal
and really stretch out the tonal range. You will have better results doing
an extreme contrast move with a system that does its color correction
computations in a higher color space. DaVinci Resolve works in 32-bit
floating point, as do Apple Color and Color Finesse. Avid works at 10-bit.
All of them have to convert these color corrections back to the original bit
depth of the source footage or the highest output bit depth, which is often
8-bit, 10-bit, or 12-bit.
Knowing all of that, if you find the need to raise the entire tonal range
of the picture equally , or to compress or expand the contrast (entire tonal
range) of your picture equally , then feel free to use Brightness and Con-
trast controls. An example of this could be in a nonlinear editor: if you
want to reduce the overall contrast of an image quickly so that a title or
text “pops” over the background more, then lowering contrast would be
an ideal tool.
Although you might do your color correction with only one of the
following products, I hope you'll check out the description of how the
corrections are done in each of the products. I can't give descriptions of all
of the products out there, so I'll show you specific GUI tools from a cer-
tain representative sample of products. The way your particular product
works may not be included in the list, but the basic operating principles
will probably be similar to one of the other products mentioned here.
Some applications or plug-ins have very “proprietary” tools that I'll some-
times mention and show. Other times, the basic tools operate nearly iden-
tically across all color correction products. In that case, it's hardly worth
describing the same process over and over, so I'll select an application that
is representative of them all. Interfaces change from release to release and
products come and go, so I'll try to just give an overview here.
As I've mentioned, there are a lot of NLEs, standalone color correctors,
plug-ins, and compositors out there with color correction tools. Covering
them all—and knowing them all thoroughly—is impossible, but I will
show you some of the main ways that you can affect your tonal correc-
tions in each of several applications.
Just before I inished writing this edition of the topic, Adobe pur-
chased IRIDAS and its color correction application, SpeedGrade. Because
of the timing of the acquisition, I won't be discussing Adobe's color cor-
rection application in this topic, but the principles of operating it will be
the same as using the tools in many of the other applications included in
the following chapters.
Let's start with the tools in DaVinci Resolve. You should really read
about all of the different applications, because certain tips and material
may be covered only when I discuss that specific application, even though
that information may pertain to more than one application. I also believe
that colorists might become more like editors, who need to know multiple
D e f i n i t i o n
bit depth: The number
of bits (the smallest data
amount, basically on or
off binary information)
used to describe a color.
There's a little confusion
about bit depth numbers.
Sometimes what is referred
to as 8-bit is the same as
24-bit because they are
saying that 8 bits per color
channel multiply to 24 bits
(8 × 3); 8 bits of color depth
gives you 256 shades of
gray. Then you multiply
those 256 shades of gray
times the three color chan-
nels (256 × 256 × 256) to
show how many colors you
can describe in that color
space (16.7 million colors).
And 10-bit video has 1024
shades of gray instead of
256. Obviously, 10-bit video
is going to be preferable
for color correction. The bit
depth computations here
generate numbers that are
on the theoretical limits.
You are really limited in
the actual number of levels
of tones and colors by
your recording and display
devices and the color
spaces that they represent.
 
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