24p stutter

[Tom Brooks]

Do you have Motion Blur turned on in After Effects? 24P motion will look very different if you aren’t making your animation style accommodate it. Moves might need to be slower, motion blur more pronounced. Assuming your AE render truly matches your sequence settings, I’d say it’s probably a combination of these items and the nature of 24P.

[Charles Caillouet]

> …graphics created in After Effects for my 720p/23.976fps stutters in my sequence. …
You can really tell with the graphics because there is a lot of panning and camera movements. Any ideas how I can smooth this out?

Jeremy,
When cinematographers shoot at 24 fps, they are required to take care in camera movement because of the slow update rate. When you shoot at 60 frames or fields per second, the eye sees motion as continuous from frame to frame, with no “blank” time between captured frames. This is a result of keeping the shutter “off” for most 60 fps capture. You capture all the motion during each frame.

If you don’t use a shutter when shooting at 24 fps, two things happen. The blur in any given image is increased because the exposure time is increased from 1/60 to 1/24 second. And the clip doesn’t have the same look as a typical film clip, where the shutter is typically 1/48 second. Obviously these two results are related; the shorter the exposure time for each frame, the less blurry the image but the larger the jump between captured motion in each frame. You don’t capture all the motion that occurred in that frame time.

So you have to decide how much blur to add. In the camera, you select a shutter speed or shutter angle. In AE you have to decide how much motion blur to crank in.

Then you control the speed of the camera motion to impart an emotion to your audience. Traditional video has not had all the options of film in this area because we did not have such a wide range of exposure times available to us. We couldn’t practically go longer than 1/60 second in most cameras. That also meant that we had fewer issues with camera mottion. If we did a swish pan, the result was almost continuous motion blur, not judder.

In 24 fps, if you do a swish pan, you can decide if you want it to blur like video (360 degree or 1/24 shutter, or judder harshly (narrower or shorter shutter.) The judder can make a viewer very uncomfortable and that can be very useful in a thriller, or very distracting in a love scene.

You have the power.

crc

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