Smoke, Haze, Fog, what’s the difference?
By Jordan Tomkins
Smoke, Haze, Fog, what’s the difference?

Smoke, Haze, Fog, what’s the difference?

It can be an easy mistake to think that all of the above are the same thing. Indeed, it often occurs where someone may ask for one by name, whilst fully expecting something completely different. Below we explain the different types of effect in more detail.

Smoke machines create a cloud of smoke that lingers in the air and is often used to accentuate lighting effects or as a theatrical effect. The smoke from conventional smoke machines is created by smoke fluid (a slightly thickened transparent liquid) being pumped onto a hot plate which vaporises it in a white smoke.

These conventional smoke machines are good for creating a large plume of dense smoke quickly, however can cause issues with sight lines, and the smoke does not necessarily dissipate very quickly.

Smoke particles can also set off fire alarms in venues.

Haze is similar to smoke in its use and creation, however is more subtle. It is used to create a slightly hazy atmosphere (hence the name!) which allows lights and lasers to create beams that cross the room. It is not as thick as conventional smoke, and the intensity can be adjusted using a lighting console. It is often used in conjunction with stage fans in order to disperse it to fill a venue evenly.

It is a common misconception that haze machines do not set off fire alarms. They are less likely to than smoke machines, however it is still a very real possibility and therefore is still recommended to isolate the fire alarm in a building before using one.

Haze hangs in the air, but does dissipate eventually.

Dry Ice is the solid form of carbon dioxide (CO2) and comes in chunks like regular ice. When it is dropped into water it creates a smoke that is very dense and has a tendency to fall to the ground in mid to high ambient temperatures.

A dry ice machine or sometimes informally ‘pea-souper’ is the name for a machine that is used in live events to help the smoke process. This is essentially a large bath that keeps the water warm and allows the dry ice to be lowered in safely.

Dry Ice is extremely cold and is very dangerous if touched with bare hands. It should only be handled by competent and experienced technicians.

People often see dry ice effects on TV and want to create these effects for their events. Creating a dry ice effect on a large scale (such as on a large stage) can be very expensive as the dry ice is costly. Also, to get the effect that is seen on popular talent shows requires a very controlled environment where ambient temperatures are high and there is minimal air flow in the venue. Even the slightest air movement in a venue can whisk away the smoke effect.

As the smoke warms to room temperature the smoke disappears and turns into an invisible gas. There is no mid-air smoke which keeps the line of sight clear.

The dry ice effect can be created by super-cooling smoke from a conventional smoke effect. This can be done a small and basic level by simply pushing smoke through a bucket of ice and this method is sometimes used for amateur theatre shows. There are also professional refrigeration devices available that cool the smoke. These tend to be quite costly but can be effective in some environments.

The downside to this method is that, as the smoke warms, it rises and can sometimes not achieve the desired look.

Co2 is often used to create a large, instant and high velocity jet of cold smoke. This is done by allowing free flow of CO2 gas from a gas tank. This can be used for stage smoke effects where residual smoke is inappropriate. It is can also create an interesting effect when sprayed directly onto a dancefloor, which is common abroad but there are concerns over the safety of this practice and it is generally not done in the UK.


PYTCH have a wide range of special effects in stock, if you would like to hire the kit to bring smoke, haze or fog to your production, visit our hire website.

If you're unsure, just get in touch to discuss further.