Step Printing

Frames repeat and skip at once, so the movement stutters forward and drags a smear behind it. A figure crossing the frame arrives in pieces, each one blurred into the next.

It puts the audience at a remove. The world carries on at its own pace and the person in the middle of it is rendered differently from everything else, which is why the look attaches so readily to loneliness in a crowd.

The camera runs at a low frame rate, often around 8 frames per second, with the shutter open long enough to smear whatever moves. Each captured frame is then printed two or three times to fill 24 frames per second.

That combination is the whole effect. The low capture rate gives the jump, the long exposure gives the trail, and the reprinting stretches the result back out to normal running time.

The background is usually left at normal speed, or a second pass of ordinary footage is laid under it, so the treated subject reads against a world that is behaving.

Use it on a character moving through a busy place, on a chase seen from inside it, and on any beat that should feel simultaneously slowed and jagged.

Skip it when the audience needs to read detail. The trail destroys faces and hands, so nothing that depends on an expression survives.

Slow motion is smooth and complete, with every frame present. Step printing drops frames and smears what is left, so it is jagged where slow motion is fluid.

A plain stutter repeats frames with no smear. If the moving parts have trails behind them, the printing is doing more than repeating.

Wong Kar-wai and Christopher Doyle made this the signature of Chungking Express (1994) and Fallen Angels (1995), treating the lead so they blur and stagger through Hong Kong while the crowd around them keeps moving normally.

You get ordinary slow motion, smooth and trailless. Ask for frames to repeat and skip, and for smeared trails on the moving parts.

The second failure is one half of the effect without the other. A stutter with clean frames is a different technique, so name both the jump and the smear in the same sentence.