Appendix 1

The Filmmaker’s Guide to Final Cut Pro Workfl ow
mind by the process of “persistence of vision,” the phenomenon where bright images are held in the
retina of the eye for a fraction of a second.
Modern Digital Formats
With the newer digital video formats, often the interlacing is removed or never used in the fi rst place.
These formats are referred to as “progressive” because the entire image is traced in one pass of the
fl ying spot. This creates a much more stable image with much less jitter. However, if the frame rate
stays at 29.97 or, even worse, 24, the image is now fl ashing on and off at such a slow speed that the
image will appear to be fl ickering. To solve this problem, the image is traced in more than once. On
most HD sets, all images are displayed interlaced at 59.94 fi elds per second. On some monitors,
every frame is displayed twice, a process called line doubling.
This same system is used with motion picture fi lm projection. In the theater, each frame is projected
twice; the screen is fl ashing on and off 48 times per second. If the image were fl ashing at the frame
rate of 24 per second, the image would be unwatchable.
New video formats contain an I or P in their names to indicate if they are interlaced or progressive.
A format of 720p is therefore progressive, 1080i, interlaced. The number in the name of the newer
HD video formats refers to the number of scan lines. The exception to this rule is 24P, an expression
that refers to the frame rate. 24P is not a video format, but rather a collection of formats that run at
a 24 or 23.976 FPS rate. The expression 60i also refers to the frame rate or, in this case, the fi eld
rate. The 60i simply refers to common 29.97 FPS interlaced video. This is called 60i instead of 30i
to reinforce that in 60i interlaced video, each fi eld is a unique slice of time. The image, and therefore
the movement, were sampled and recorded almost 60 times every second and so is much smoother.
Remember, 30 is a misnomer, the true frame rate is 29.97 and so the fi eld rate is 59.94. 24P is also
a misnomer; the real frame rate is usually 23.976, which also is usually rounded off as 23.98. It all
means the same thing except there is a rarely used, true 24 FPS version of 24P.
While digital images are still displayed using Farnsworth’s line scan system, digital video is recorded
as frames of pixels, tiny picture elements of recorded color. Each pixel’s color is recorded as a number
value in binary code, and each number represents one specifi c color. The larger the number recorded,
the more colors that can be reproduced. Most formats record this value as three separate binary numbers,
one for the red component, one for the green, and one for the blue. Most formats record an 8-bit binary
value, or 256 values of red, green, and blue for a total of 16,777,216 colors. Some high-end formats
record a 10-bit number or 1,024 values of red, green, and blue for a total of 1,073,741,824 colors.
Some formats also use a “lookup table” of colors. Here is analogy for the way a lookup table works.
In “standard” 8-bit color formats, every binary number represents a color, like a huge room with
more than 16,000,000 crayons in it. Different formats have a different “color space.” In other words,
they use a different set of crayons. Each crayon has a code number on it and each pixel is colored
in with the corresponding crayon. With a lookup table, there are an infi nite number of crayons. At
the beginning of the image, a code sets the lookup table; it picks 16 million of these crayons to put
in the room and use in the image. If there are no reds in the image, there will be no red crayons
placed in the room. Depending on the image, this dramatically increases the apparent “color space,”
but to truly increase this space, you need a bigger room. One that will hold more crayons, such as a
10-bit room with space for more than a billion crayons.
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