Lensing
Shallow focus
Shallow focus keeps one plane of the image sharp while everything nearer and further falls soft. It directs your eye by making the rest of the frame literally harder to look at.
Focus is the bluntest instrument a film has for controlling attention, and the most polite — it never tells you where to look, it simply makes everywhere else difficult.
The interesting decisions are not where the focus sits but when it moves. A rack focus — shifting sharpness from one subject to another within a shot — hands your attention from one thing to the next without a cut, and often reveals that something has been in the frame the whole time.
Shallow focus also isolates. A character sharp against a dissolved background is cut out of their surroundings, which can read as intimacy or as detachment depending on what the scene wants.
Where you have seen it
A conversation where the background softens to nothing, so two faces float in a room that has stopped mattering. Or the reverse: focus pulls past a character to something behind them, and the scene changes meaning.
What to watch for
- What is sharp, and what has been softened out of the argument
- Focus shifting during a shot, and what it hands you
- Deep focus used deliberately, keeping everything sharp so you must choose