Final Cut Pro – Avoiding Interlacing Problems
Be careful of flicker when working with NTSC or PAL video.
NTSC and PAL video are both interlaced. So is any HD font that ends in the letter “i” — 1080i, for example.
Interlacing divides the image into alternating sets of lines – odd lines and even lines. Then, it displays first one set, then a fraction of a second later, the second set. Some formats, like NTSC, display the even lines first. Other formats, such as HDV, display the odd lines first.
To keep confusion to a minimum, FCP hides interlacing by displaying just one field at any time. If you want to see interlacing, set the magnification of either the Viewer or Canvas to 100%.
However, if you don’t take some precautions, interlacing can cause some bothersome visual anomalies to pop up in your video – indicated by thin horizontal lines radiating from all moving objects or wild flickering on still frames.
Here are two things to keep in mind:
* Still frames of interlaced video will always flicker, except you can’t see the flicker on a computer screen. Be sure to apply a deinterlace video filter.
* When compositing two images, if both are interlaced and both are scaled to 100%, be sure they align on even lines in the Motion tab (the right-hand number for the Center parameter).
Courtesy of Larry Jordan