Why does my video look juddery or stuttery?

Video motion looks smooth only when the amount of blur in each frame roughly matches the distance things move between frames. Every judder problem is a mismatch of that relationship somewhere in the chain.

Step by step

1. Check the shutter speed against the frame rate.The film convention is a shutter of roughly one over twice the frame rate: 1/50 second at 25fps, 1/60 at 30fps, 1/100 at 50fps. That gives each frame a natural amount of motion blur. Shooting at 1/1000 gives razor-sharp frames with no blur, and the eye reads the jumps between them as stutter.
2. Use an ND filter rather than a fast shutter.Outdoors in daylight, keeping the shutter at 1/50 usually overexposes unless you close the aperture right down. A neutral density filter cuts the light so you can hold the correct shutter speed. This is why video shooters carry them and stills photographers often do not.
3. Slow your panning down.There is a limit to how fast the frame can move before individual frames become visible as separate images. It is much slower than it feels — a full pan across a scene should take several seconds. Wide lenses tolerate faster panning than long ones.
4. Match your editing project to your footage.Dropping 30fps footage into a 25fps timeline, or the reverse, forces the software to duplicate or discard frames, which produces a regular hitch. Set the project frame rate to match what you filmed, and film everything at one frame rate.
5. Pick a frame rate for your mains supply.In the UK the mains runs at 50Hz, and many artificial lights pulse with it. Filming at 25 or 50 frames per second keeps in step. Filming at 30 or 60 under those lights produces rolling bands or a pulsing brightness that no editing removes.
6. Distinguish judder from dropped frames.Judder is regular and affects all motion. An occasional hard hitch is dropped frames — a card too slow to keep up, a phone getting hot, or a computer struggling to play back. Check the file on a different device before blaming the camera.
7. Check playback rather than the file.Editing software previews at reduced quality and often stutters when the computer cannot keep up. Export a short section and watch it properly before diagnosing anything.
8. Use a higher frame rate deliberately for slow motion only.Filming at 50 or 60fps and playing back at 25 or 30 gives smooth slow motion. Filming at 60 and playing back at 60 gives the smooth hyper-real look people associate with video rather than film, which is a choice rather than a fault.

Tips

• If you cannot change the shutter speed on your phone, a third-party camera app usually gives you manual control including shutter and ND-equivalent adjustment.
• Judder is far worse on high-contrast subjects and detailed backgrounds. Panning across a brick wall shows it much more than panning across a lawn.
• Motion smoothing on a television adds interpolated frames and makes film look like video. If footage looks oddly smooth on one TV and normal elsewhere, that is the cause.

Common mistakes

• Using a fast shutter to avoid overexposure outdoors — It removes the motion blur that makes movement read smoothly. Use a neutral density filter or a smaller aperture and keep the shutter at twice the frame rate.
• Mixing frame rates within one project — Every clip that does not match the timeline is converted, and the conversion introduces a regular hitch. Decide a frame rate before filming and use it throughout.

If it doesn't work

Questions people ask