-
Frame Rate Confusion
I have some media shot on an AVCHD camera. Shot at 1080 60i. I’ve always assumed 60i to be 60 fields per second, or 30 frames per second.
I’ve noticed some odd differences in how the video looks in FCPX vs. Quicktime. The video is of a prop (as in propeller) plane. The plane has three blades per engine. In FCPX you see three blades, the blades look solid. Playing back the same clip in Finder using Quicktime, you see 6 blades and they appear to have an interlaced artifact to them.
I played them back on the camera and the clip looks like the Quicktime version, you see 6 spinning blades.
If I export the clip in FCPX, using various settings, the plane has 6 blades.
Attached are two screen shots (only way I could show what’s going on). One shows 6 propeller blades (Quicktime/camera playback) the other shows 3 blades (FCPX playback).
What’s going on inside FCPX to provide such a different image?
-
4 Replies
-
What you’re probably seeing is a result of FPX only showing one field in the viewer. There’s a setting in the upper right-hand corner where you can tell it to show both fields. That artifact you’re seeing is due to the fact that QuickTime is trying to play interlaced footage on a progressive computer screen. If you made a DVD of your export and played it on a regular television it would look totally fine. All computer screens are progressive but your footage is interlaced. If you want to keep your footage interlaced, then you’re going to have to put up with that artifact if you view both fields.
Andy
https://plus.google.com/u/0/107277729326633563425/videos
-
It’s been a while since I went to frame rate school. Seems no matter how much I learn about these simple facts, I always seem to forget. The FCPX setting is yet another great example.
Thanks.
-
Yepp. It’s this little detail that you set at the top right of your viewer. Andy beat me to it. 😉
-
Always something new to learn about FCPX (viewer setting). So if it had been shot at 60p, the adjacent frames would show 3 blades, but shifted by 60 degrees. Not sure how the playback on FCPX and a compressed version to 30 p (typical for Youtube) would look, I am guessing during play back it would like like 6 blades. Reminds me of the stage coach wheels in old movies that would appear to rotate backwards.
Reply to this Discussion! Login or Sign Up