Cor­win says:

I’m work­ing in Final Cut Pro, but the video in the viewer looks very dis­torted… there’s lines all through it, and it looks inter­laced. I just switched com­put­ers from an eMac to the new iMac. I don’t get it, I even have the can­vas size at 100%, so it should be run­ning at full qual­ity. Will it look like this in the fin­ished prod­uct? How do I fix this?

Short answer: your fin­ished prod­uct will be just fine.

Long answer: Most video you tape nowa­days is inter­laced. The LCD dis­play on your iMac is not inter­laced. That’s why your video looks like junk: it’s flash­ing a bunch of lines on the screen, but that’s not how your dis­play works. AH!

So how do you fix this? To work around this prob­lem, you could use a dein­ter­lace fil­ter on your whole video, but then it’d look like junk on inter­laced dis­plays (old tube TV’s and com­puter mon­i­tors). Instead, you have to trick Final Cut Pro into dein­ter­lac­ing your video only when it’s in your can­vas: just resize the win­dow slightly and select “Fit to Win­dow” in your can­vas’ view options. As long as you’re not view­ing the video at 100%, it’ll look just great. Yeah, I know. Silly prob­lem!

Oh, and if you use this trick, your fin­ished prod­uct will still be inter­laced when you export it. And in most sit­u­a­tions, that’s a good thing.