Graphics Reference
In-Depth Information
Call up the “grayscale_neutral” and “grayscale_cool” movies from the
DVD's tutorial media folder. Hopefully, you've got a nice external wave-
form monitor to use, but the internal one will certainly work for this
tutorial. Read your app's manual to see the image using an RGB or YRGB
waveform monitor. If you use a YRGB view, remember that the first cell
represents “luminance” and the next three cells are red, green, and blue.
I will be doing this tutorial using an RGB view, and I'll do this correction
using Color.
With the “grayscale_cool” movie in the timeline and Color's Primary
In Room active, you can see that the chip chart does not look the same
in each of the color channels. Switch to the “grayscale_neutral” movie.
Notice how all three waveforms are identical. This means that in each
tonal range, the amounts of red, green, and blue are the same.
The chip chart is made up of shades of gray, from black to white. Pure
white is the presence of red, green, and blue light in equal amounts at “full
power.” Measured on an RGB waveform set to IRE or percentages, this
means that red, green, and blue are each at 100IRE or 100 percent. If you
were measuring in RGB color space in 8-bit, red, green, and blue would
each be at 255. In video color space at 8-bit, they would be at 235. In
10-bit RGB color space, white has red, green, and blue at 1023. In video
space, they would be at 940.
Black is the absence of any color, so in RGB color space at 8-bit or
10-bit, that would be 0 for all colors. If the black has “setup” added to it
for NTSC, then black is 16 in 8-bit and 64 in 10-bit.
So, that last paragraph had a lot of numbers thrown at you. The gist
of them all is that pure white, pure black, and pure gray means that the
red, green, and blue channels all match, no matter what level they're at.
Knowing this makes it easy to watch the RGB Parade waveform and bal-
ance the color by making the top and bottom of the waveform monitor
match across all three color channels. You can't really do this with gam-
mas in real-world images, usually, because the midtones tend to have a
specific cast to them for a reason, like skin tones. You don't want to bal-
ance a skin tone so that all three color channels are the same, or the skin
tone would be gray.
Pure white, pure black, and pure gray means that the red, green, and
blue channels all match
Having learned that black, white, and gray should match across the
channels, let's try to use RGB levels to balance the shot. There are other
tools that could also do this, but we'll save them for later. In Color, go to
the Primary In room and use the Advanced Tab which is on the right side
of the control screen about half way down.
 
 
Search WWH ::




Custom Search