Kurosawa in the editing room
[Kurosawa] is particularly averse to any scene which would tend to explain a past action, to predicate itself in history as it were. Kurosawa’s premises are all in the future and this is what makes them so suspenseful, one is always having to wait and see.
Just as he always cuts out business which gets a character from one place to another, which, for merely geographical reasons, has him—say—opening and closing doors; so, Kurosawa is impatient with any shot which lasts too long for no good reason. His short scenes are often mere flashes. In Seven Samurai one of the shots showing a man pierced by an arrow is just twelve frames (1/2 second) long. If you blink, you miss it…Another example is during one of the fight scenes in Sugata. There was a cut showing the opponent flying through the air, having been thrown by Sanshiro. Kurosawa calculated its length and viewed it. Everyone said that it was tremendous. Kurosawa said it looked just like a kite. He halved it, then halved it again. The resulting flash is precisely what he wanted.