Haze Machine

Haze and fog are often mentioned in the same breath on set and are two different things. The fog machine emits a visible cloud that drifts and dissipates. The hazer creates a fine veil of much smaller particles that distributes throughout the space and stays there — you don't see it as fog, you only see it because suddenly every beam of light is visible in the shot.

Why That Makes a Difference

Backlight without haze is a bright edge on the actor. With haze, it's a beam that travels through the space. That's precisely why the hazer is used for almost every interior shot with hard light sources: clubs, concerts, warehouses, churches, any scene with windows and sun. It doesn't replace lighting, it makes it visible.

On Set

• Start early. Haze needs ten to twenty minutes to distribute evenly. Anyone who starts it just before "action" will shoot the first take with wisps and the third with a veil — and will see it in the edit.
• Maintain density throughout the day. The veil dissipates as soon as someone opens a door. A crew member monitors it instead of adding more intermittently.
• The camera measures it. Haze raises the black level and lowers the contrast. Anyone shooting without it and editing later will get two different images.
• Fluid and smoke detectors. Water-based fluid is common; oil-based lasts longer and is not permitted in many locations. Smoke detectors are reported and switched off, not taped over.