One of the most important features many of us look for when buying a camera is undoubtedly variable frame rate, specifically 60p. We want to be able to capture slow motion, and the only way to get it right is to over-start – meaning shooting more frames than you need so that you can slow it down in post without skipping frames. Unfortunately, many of today’s great cameras (like the Blackmagic Cinema Camera or the Canon C100) don’t have a 60p option, which makes our lives difficult since we’re forced to rent professional equipment every time we need slow motion. The good news is that many cameras that lack 60p do have a 60i option, and while you may have avoided it like the plague in the past, this article will show you how 60i can become your new best friend.
For those of you who haven’t shot 60i or 60p before, let me briefly explain the differences. 60i represents 60 interleaved Fields (not frames) – 59.94, actually, to be precise. 60p, on the other hand, represents 60 individual frames They are complete images in themselves. They may sound similar, but they are very different. If you’ve ever shot something on tape and fed it into a computer, you probably know what a field looks like. You may see an image like this when paused:
When working with true 60p footage, you can slow it down to 40% on a 24p timeline and it will play back in perfect slow motion, giving you beautiful results. 60i, on the other hand, cannot be dropped directly into a 24p timeline and slowed down, as it requires two fields to create a frame, meaning you actually only have 30 frames to start with, rather than 60. If you try to slow down a 60i image to 40%, it will look just as bad as slowing down a 30p image to 40%. There just aren’t enough frames to make up for the slowdown, and you get very jumpy footage.
Having said that, there is a way to solve this problem, and in FCP X it’s very simple.
All you need to do is select your clip in the event, click the inspector, and change the view to Settings. From there, just click “Deinterlace” and voila, your clip can now be treated as a 60p clip. In fact, the inspector automatically updates to view the clip as a 59.94p file instead of a 29.97i file.
Now you can put your newly converted 60i/60p clip into a 24p timeline, slow it down to 40%, and you’ll get really nice slow motion.
The idea behind this is that FCP X will deinterlace your footage and effectively convert it to a 60p clip before you slow it down in the timeline. You can do this manually using almost any software, but FCP X makes it very easy.
Is this as good as using a true 60p clip? Not really, but it’s not as far off as you might think. There is less information in the image than the 60p clip (because it uses fields rather than frames), but the motion should be almost as smooth because each field is different, so FCP New framework.
But it’s important to remember that when shooting 60i footage, set your shutter to at least 1/120, just like when shooting 60p. If you don’t do this, you won’t be able to effectively slow down the footage.
I’ll be posting an ad next week that was shot primarily on the C100 at 60i, and will be sure to update this post with the final product so you can see how it works.
For editors out there, be sure to check out my recent post Achieve a striking look when color grading.
