Strobes, haze and lasers: a safety policy for automated lighting

Software that runs a rig on its own has to decide what it is allowed to touch, and the honest version of that decision is a list rather than a promise. HitLight's Auto Show drives colour, intensity, a steady open shutter and eligible movement. Everything with a physical hazard attached to it — smoke, flame, lasers, flashing strobes, blinders, UV, and anything the software cannot read the meaning of — is removed from every automatic code path, not held back by good behaviour at runtime.

That distinction matters. A rule enforced in code cannot be forgotten, cannot be overridden by a clever prompt, and does not depend on the assistant behaving well on a bad night. The assistant cannot reach those channels either.

Which channels will Auto Show never drive, and why?

Six channel classes are excluded, each for a different reason. The reasons are worth stating separately, because "dangerous" is doing a lot of work as a single word: a hazer and a laser are both excluded, but almost nothing about why they are excluded is the same.

The last row is the one people underestimate. Most genuinely alarming behaviour from automated lighting comes from a value written into a channel whose meaning nobody checked, rather than from a system deliberately deciding to strobe. Refusing to drive channels it cannot interpret removes a whole category of surprise.

Does Auto Show strobe?

No. Auto Show does not drive flashing strobe channels or blinders — it holds a steady open shutter and works with colour, intensity and movement instead. Where HitLight does produce strobe bursts elsewhere in the app, they are capped for photosensitivity. Both of those are design decisions in the software, and neither is a medical guarantee.

Photosensitive epilepsy is triggered by flash rate, contrast, coverage of the visual field and duration, in combinations that vary between individuals. No cap makes a light show safe for everyone. If your programming includes flashing content — whether or not you programmed it by hand — signage at the entrance and a warning before the show remain a venue responsibility, and in many venues a legal one.

What is the difference between Stop, Fade Out and Blackout?

They are three separate operator actions with three different outcomes, and knowing which one you want before you need it is worth more than any amount of programming. Stop leaves the rig lit, Fade Out takes it down over a second, and Blackout is immediate.

The reason these are three controls and not one is that "make it stop" means different things at different moments. An operator who only has Blackout will use Blackout for problems that did not need the room to go dark, and an operator who only has Stop has no way to end anything quickly.

What happens if the software itself hangs?

HitLight runs a native watchdog outside the interface that latches DMX output to an all-zero frame within two seconds if the app stops responding. Output stays down until an operator explicitly restores it. The design choice there is deliberate: a hung application should take the rig dark rather than leave the last frame on the wire indefinitely, and it should not quietly resume on its own once it recovers.

Note what that means in practice. A software fault produces darkness, not a stuck strobe — but it does produce darkness, on a live rig, with no warning. That is a scenario worth having a house-light answer for, in exactly the same way you would for a power cut.

Does "the software will not do it" mean the rig is safe?

No. The exclusion list means one specific thing: an automatic system will not fire those channel classes on its own. It says nothing about whether your rig is safe, because almost everything that makes a rig dangerous happens outside the software entirely. The operator remains responsible for all of the following, and no amount of restraint in an application transfers any of it.

• Addressing and patching. A fixture patched in the wrong DMX mode will read the wrong channels for everything, which is how a value intended for a dimmer lands on something else. Confirm the mode and address on the physical unit, not on the patch sheet.
• Rigging and installation. Clamps, safety bonds, load ratings, trim heights and what is underneath a fixture are mechanical questions with mechanical answers.
• Electrical safety. Supply, protection, cable condition and inspection regimes are governed by local regulation and by your venue, not by a lighting application.
• Atmospherics, lasers and pyro. If you fire them manually, every rule that applies to them still applies. The software declining to automate them is not permission to skip the risk assessment when you do it yourself.
• Fixture profiles you generated. Generated profiles stay marked as drafts until you test the channels on the real fixture and confirm them, because a wrong profile is a wrong channel map and a wrong channel map is how surprises happen.
• Venue rules and the audience in front of you. Warnings, signage, sightlines, egress lighting and who is standing where are yours.

How do you test Blackout at a new venue?

Test it before doors, every venue, every time. It takes fifteen seconds and it is the only way to know that the control you will reach for in a hurry is actually connected to the lights in front of you.

1. 1

   Bring the rig up to a real look

   Not one fixture at 10% — a look with everything you intend to use lit, at the level you will actually run. Testing Blackout against an almost-dark rig proves nothing.

2. 2

   Press Blackout and watch the room, not the screen

   Every fixture should go dark at once. If one stays lit, you have found an addressing or universe problem now rather than in front of an audience.

3. 3

   Restore, and check what came back

   Confirm the rig returns to the look you left, and that nothing came back at the wrong level or the wrong colour.

4. 4

   Show one other person where it is

   At least one person who is not you should be able to take the rig dark. In a venue, that is whoever is on shift; on a gig, it is whoever is standing nearest the desk.

Is any of this a substitute for venue safety procedures?

No. HitLight's exclusion list, strobe caps and watchdog are software behaviours, and they are not a substitute for venue safety procedures, risk assessments, local regulation or a competent person being responsible for the rig. They narrow one failure mode. Everything else on the list above is unchanged, and the person operating the show still carries it.

We would rather write that plainly than imply otherwise. Automatic lighting is useful precisely because it is boring about the dangerous parts, and a tool that claimed to have made your rig safe would be making a claim it is in no position to make.

The fuller policy, including how fixture profiles are verified and what the assistant is and is not allowed to reach, lives on lighting safety. What HitLight sends to a model, and what it never sends, is on AI and your data.