24fps film transferred to 60i video by repeating each frame twice. Standard for PAL regions—but creates flicker on fast motion.
You have 24p film footage and need it for 60i video? Then you'll end up with 2:2 pulldown — a conversion method that simply writes each film frame twice in a row into the video format. This sounds harmless but leads to visible artifacts when fast motion comes into play.
The Mechanics: A film frame sits on the sensor for two video frames. At 24 fps × 2 = 48 frames per second, then the whole thing is upscaled to 60i — with a bit of interpolation added, depending on the encoder. The result: a kind of stuttering with pans and fast object movements that you can't simply smooth out because the information isn't there. The motion blur is gone, the movement looks choppy. This looks particularly bad with camera pans — each frame briefly flickers before the next one arrives.
In practice, you encounter 2:2 primarily in PAL regions when DCP material (24p) needs to be converted to SD video or older broadcast standards (50i PAL). Some editing suites still do this automatically without anyone thinking about it. The alternative — 3:2 pulldown — was the standard for NTSC (60i) for a long time because 24 fps and 60i align better mathematically. 2:2 is crude, but for PAL countries, it was the workhorse for a long time.
On Set and in Editing: You'll notice the problem at the latest during confirmation or mastering. Fast movements look jerky, almost like stop-motion. Solution: Either work in native 50p or 25p if the camera allows it — then you don't need any pulldown at all. Or accept the look and design your shots accordingly: longer takes, smoother movements, more motion blur in the camera. Some DoPs have learned to work with it; others hate it and insist on frame rate conversions that interpolate more intelligently.
Today, 2:2 is less relevant because most productions run digitally in native 50p or 24p anyway and only convert at the end of the pipeline. But if you see old archive material with this artifact or have to deal with legacy delivery specs — now you know where the stuttering comes from.