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Cinematography3 min read

LESSON 105

Day for night

Shooting night scenes in sunlight.

IN THIS LESSON

  1. What it is
  2. Why blue reads as night
  3. Exposure and sky
  4. Practice: making it convincing

What it is

Day for night is a set of techniques for making a night scene while shooting in daylight. It is used when filming at real night would be too hard or too expensive, because film and digital sensors are much less sensitive than the eye in very low light, and a real night scene lit only by the moon may show almost nothing. The usual method is to underexpose in camera or darken in post-production and add a blue tint. In France the technique is called la nuit americaine, after its frequent use in American films, which also gave Francois Truffaut's film its title.

Why blue reads as night

Moonlight is not actually blue, but it looks bluish to our eyes because of the way human vision shifts in dim light, known as the Purkinje effect. Theatre and silent film adopted blue for night scenes, and the convention stuck. In colour work, one method is to balance for tungsten light at 3200 kelvin while shooting under daylight, so the scene goes blue while artificial lights in frame such as car headlights or lit windows stay white. With digital post-production, the colour shift is usually set in camera and the darkening left to the grade.

Exposure and sky

A typical approach underexposes by about two stops, often with a neutral-density filter so the aperture can stay where it is. The sky gives the trick away fastest, so it is usually kept out of frame or darkened. In black and white, a red filter turns a blue sky almost black. As cameras have become more sensitive, true night shooting has become easier and day for night is used less often than before. Low-light cameras now let many productions shoot real night with modest lighting, but the old technique still saves money on large exteriors.

Practice: making it convincing

This is working practice. Shoot when the sun is low and behind or to the side of the subject, so you get rim light that can read as moonlight and long shadows. Avoid the sky, or shoot toward a dark background such as trees. Add practical lights in frame, a torch or a lit window, so the eye has something bright to believe in. Keep faces darker than you would in day scenes. Grade with care, lowering midtones more than shadows, and test on a dark screen.

Try it today

  1. 01Shoot a person walking in late-afternoon sun with backlight.
  2. 02Set white balance to 3200 K and underexpose by two stops.
  3. 03Include a torch or lamp in frame.
  4. 04In the edit, darken midtones and cool the image further.
  5. 05Watch it in a dark room and note what gives the trick away.