What is a Haze Machine?

A haze machine (also called a hazer) is a device that fills a performance space with a fine, even mist, making lighting beams and lasers visible without blocking the audience's view of the stage. Most concerts, theatre shows and club nights with moving lights use haze.

How a haze machine works

Using haze at a show usually involves four steps:

  1. Fluid: the machine turns a special fluid, either water-based or oil-based, into a very fine mist.
  2. Output: a fan spreads the mist so it hangs evenly in the air rather than in clouds.
  3. Control: the lighting engineer sets output and fan speed from the lighting desk over DMX.
  4. Timing: haze is often started before doors so the room is evenly filled by showtime, then topped up during the show.

Haze is one of the items an act asks for in its technical rider, so it's confirmed with the venue during the advance. Many teams track these requests in Crescat.

Haze machine vs fog machine

A haze machine creates a thin, even mist that is barely visible on its own but shows up light beams. A fog machine creates thick, visible clouds for effect, which can block sightlines and set off detectors more easily. Shows use haze for constant atmosphere and fog for short moments.

What to check before using haze at a venue

  • Whether the venue allows haze at all
  • The type of smoke detectors and whether they can be safely isolated
  • Who will run a fire watch while detectors are isolated
  • Ventilation and how quickly haze clears
  • The fluid type, and any audience or performer health concerns

Frequently asked questions

Will a haze machine set off the fire alarm?

It can. Many smoke detectors react to haze, so venues often isolate detectors in the performance area under a controlled procedure, with staff on fire watch until they are restored. Never isolate detectors without the venue's permission.

Is stage haze safe to breathe?

Haze fluids made for stage use are generally considered safe at normal concentrations. Some people with asthma or breathing conditions may be affected, so follow the manufacturer's guidance and the venue's rules, and warn the audience where required.

Do all venues allow haze?

No. Some venues ban it, especially older buildings or those with sensitive alarm systems. Others allow it with conditions, such as a fixed output limit or detector isolation only at certain times. Ask early in the advance.

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