Typically, an automated lighting programmer is concerned only with programming the lighting elements. However, there are also often circumstances where we are tasked with programming control of various types of smoke effects. From hazers to blasts of fog or CO2, we must use caution when programming atmospheric effects. Depending on the production, there may also be strict guidelines that must be adhered to. As with any fixture on the desk, an automated lighting programmer needs to be informed and prepared to work with atmospheric effects.
Preparing to Smoke
Every item connected to the lighting console needs to be controlled by a fixture type within the desk. When working with hazers and smoke machines, there may or may not be a fixture library available. Many of these devices have a simple one-channel control that adjusts the level of output. In this case, you can simply patch in a generic desk channel or dimmer channel to control the output. However, some machines are more complex and may require a unique library that matches their specific DMX protocol. Just like patching in any moving light, you need to ensure that you select the correct library that matches the model and mode of the smoke machine. Then you will have control of the various attributes. These can include output, fan, volume, control and other functions.
When working with the most basic of hazers, you may only be able to switch them on and off with no variable or direct DMX control. In these instances, they are typically plugged into a non-dimmable circuit or a relay. Both of these methods will ensure that they receive only a direct on/off trigger from the lighting desk. Usually, when the DMX channel is at or above 50 percent, the unit will be on, and below 50 percent, it will be off. It is vitally important to never plug these types of devices into a dimmer as the fluctuating power will cause damage to the electronics in the hazer. Furthermore, it is always a good idea to patch the control in the desk as a non-dim element (available in most lighting console libraries) so that the channel will not allow any crossfading of the DMX values.
Chasing the Dragon
Once you have your haze or fog machine connected to your desk via DMX, you should have total control of the unit. You will likely want to build some playbacks for quick access to enable and disable the output. This can easily be done by making a cuelist (or stack) that has two cues. The first cue allows for zero output and the second allows for your desired output. Now you can toggle this cuelist between the two cues to turn your haze or smoke on and off as desired.
In many cases, it may be more desirable to create a chase or looping cuelist that automatically turns on/off the smoke output. To do this, you will build the same two cues, but set a duration for each. The exact ratio will depend on many factors including the venue airflow, desired on-stage effect, union rules, performer desires, and even budget. Quite often, your value for the on time will be very different than the value for the off time. For instance, you might have the hazer on for 20 seconds and off for one minute. This way, it is only hazing for a short amount of time each minute.
Remember, too, that this cuelist/chase may want to run at all times, or only during select periods of your show. You should ensure that there is a clear way to indicate when the playback is active and an easy way to release it when desired. Furthermore, you might want to give it a priority to not release when you send a release-all command, otherwise you may forget to turn it back on. Most consoles have macro commands that will allow you to build the hazer cuelist/chase on and off commands into your cues. I find this very useful for many productions so it will automatically turn off during intermission or breaks.
That Special Smoke
Sometimes, atmospheric effects under the control of the lighting programmer go beyond typical haze and fog. I have had control of various types of effects, from CO2 cannons to dry ice low-fog generators. Additional care is often required with these special effects due to the potential dangers and high costs of materials. You should always consider additional safety personnel, procedures, and dead-man switches when utilizing potentially harmful DMX controlled effects.
I like to build in my own additional safety measures when working with these types of smoke effects. For instance, on a recent corporate event we had a large number of CO2 jets that shot an effect up at the front of the stage. This was to be used at the finale of an opening number and at no other times. Although we had many different safety devices employed directly on the stage, I still built additional control into my desk. I was not actually triggering the smoke machine, but rather DMX controlled solenoids that opened a valve letting an intense amount of compressed gas to shoot up from the stage floor. A technician on the stage had to open a valve earlier in the line to arm the system, thus allowing an additional level of safety.
For this production, I did not want to risk triggering the solenoids to open at any time in the production other than the specific cue. For this reason, I built several macros to ensure that the specific DMX channels in control of the jets were parked at zero at all times except during the essential cues. I even had a macro that would park the channels when the show was loaded or the desk started up. This way they would always be parked until the specific moment in the show.
Let’s say that Cue 20 was the fire cue. I had a Cue 19 that changed the lighting before this, so I added a Cue 19.5 that unparked the solenoids but kept them at their closed value. I labeled this cue ARM JETS. I played this moments before the firing cue (after getting the clear signal from the stage manager). Then Cue 20 would command the jets to fire, and I had an autofollow cue (Cue 20.1) that turned them off after the desired time determined during rehearsal. This same cue also triggered a macro to again park the channels at their off value to ensure that they were no longer able to be activated.
The safety precautions in my desk, combined with the precautions by the staff on stage, ensured that the effect worked perfectly and was completely safe.
Follow the Rules
In many situations (often theatrical), you will be required to follow rules and guidelines that have been accepted and approved by Actor’s Equity, PLASA, or other governing bodies. It is important that you understand the regulations and comply accordingly. Many detailed studies have been done with most atmospheric machines providing specific ratios for use of each. This means that you must follow the ratio when you build your chase/cuelist to control the amount of smoke on stage.
If you are not familiar with these guidelines, I suggest that you search for the guidelines required in your area. They vary depending on the country and governing body. Most of these documents are very detailed and often suggest the amount of time each specific machine can be used, at what level, and for what duration.
Don’t Say No
Controlling atmospheric effects from your lighting controller is not something to be taken lightly. You must consider safety first and foremost; yet provide flexibility and control for the production. It is actually very helpful when you have the haze or smoke control on the desk as you can quickly make adjustments without requiring direct access to the machine. Just ensure that you use the proper fixture library and clearly label your controls of the channels.
You don’t want to accidently program in a blast of smoke during a quiet scene or ballad. You should also always remember that, in most cases, the audience is there to see the show, and not just the fog and lights. So don’t go crazy with your control of the machines and saturate the venue with smoke. Be responsible with your smoke, and have fun programming it along with your lighting.
