Using the Broadcast Safe filter is a good way to ensure that the levels in your project will conform to the specifications required for television. In order for the Broadcast Safe filter to be effective and accurate when used, it should be the last filter applied to a clip or nested sequence.
Final Cut Pro allows you to create imagery using any of the millions of colors your computer can produce. A mistake beginners often make when creating graphics for video is to use colors that are vivid on the computer display, but have chroma and luma levels that are out of specification for the "legal" range of color for television. Also, many modern cameras are capable of recording video levels which are beyond the broadcast-legal range for the NTSC and PAL specifications. Broadcasters adhere strictly to these specifications and will reject tapes that are not "broadcast safe," because those levels can cause problems in the television signal.
In order to achieve accurate and predictable results with the Broadcast Safe filter, it's important to understand that filters are applied in series in Final Cut Pro. In other words, the order in which a given set of filters are applied will affect the end result.
The next two images illustrate an example of how the order in which filters are applied can affect the resulting image.
Gaussian Blur, then Diffuse
Diffuse, then Gaussian Blur
As seen above, the order of the filters makes a difference, even when the same filters are used. This is why it's important to add Broadcast Safe last. If you add a filter like Proc Amp after Broadcast Safe, the result might include levels that are no longer within the safe range.
Tip: The following steps outline a simple method for adding the Broadcast Safe filter at the end of the editing workflow:
Adding the Broadcast Safe filter as a last stage (as in the steps above) can serve to ensure that video levels remain within the safe range.
For more information about using filters in Final Cut Pro, and to learn about using video scopes to monitor video levels, see the Final Cut Pro User Manual, available from the Help menu in Final Cut Pro.