Video scope restrictions and performance, Preventing illegal broadcast levels, P. 523) – Apple Final Cut Pro 6 User Manual
Page 1308
Chapter 26
Measuring and Setting Video Levels
523
III
Video Scope Restrictions and Performance
The following list describes limitations when using the Video Scopes Playback option
in Final Cut Pro:
 Your editing system requires an AGP or PCI Express graphics card. Some older
PCI graphics cards may not have enough processing power to update the Video
Scopes tab in real time.
 You must be using a format that Final Cut Pro can process in real time. For a list of
formats that Final Cut Pro can process in real time, choose Final Cut Pro > System
Settings, then click Effect Handling.
 The View pop-up menu in the Video Scopes tab must be set to Current Frame
(referring to the Canvas) or Viewer. Options such as Current Frame w/o Filters and
Previous Edit disable the Video Scopes Playback option.
When checking video scope accuracy, you can analyze all video lines only when
playback is stopped or when scrubbing. The Video Scopes Playback option updates the
Video Scopes tab using the Limited Lines (Fastest) option. For more information, see
“
Using Video Scopes in Real Time
Preventing Illegal Broadcast Levels
Broadcast facilities have limits on the maximum values of luma and chroma that are
allowable for broadcast. If a video exceeds these limits, distortion can appear in the
form of colors bleeding into one another, the whites and blacks of your program
washing out, or the picture signal bleeding into the audio signal and causing audible
distortion. In all these cases, exceeding standard signal levels can result in
unacceptable transmission quality.
For this reason, as you are performing color correction on clips in your edited
sequence, you need to make sure that the luma and chroma levels of your video stay
within the parameters referred to as broadcast-legal, or acceptable for broadcast. It is
easy to inadvertently push the levels of clips in your sequence too high, so it’s
important to use Final Cut Pro scopes and range-checking options to make sure that
the luma and chroma levels you set stay legal.