What is the hazard distance?

The hazard distance (HD) is the distance from the front of the projector lens at which the laser radiation density drops below the limit set by IEC 62471 for the relevant risk group. No unprotected persons may be present within this zone.

Why does the value differ for the US and other markets?

The American FDA/CDRH classifies laser projectors under its own methodology (21 CFR 1040), which is stricter than the IEC 62471 used in Europe and the rest of the world. As a result the calculated hazard distance for the US region is generally longer.

Do I need a safety plan even for a small auditorium?

Yes. Any RG3 laser projector requires safety measures regardless of auditorium size. Recommended measures include barriers in the hazard zone, a locked projection booth, information signs and a record in the operating documentation.

Does the calculator replace professional measurement?

No. The calculator is an indicative tool for designers and technicians. Binding values for a specific installation must be established by accredited on-site measurement, as the result also depends on the specific optics, laser condition and actual device output power.

How does the throw ratio affect the hazard distance?

A shorter throw ratio (wide-angle lens) concentrates the laser beam into a smaller cross-section and increases radiation density. That extends the distance over which radiation drops to a safe level. A telephoto lens conversely results in a shorter HD.

Laser hazard distance

Calculate the hazard distance of a Barco projector (IEC 62471) and visualise the safety zone in front of the lens.

// hazard distance

// IEC 62471

1.56 m

Hazard distance in front of the lens per IEC 62471. Within this distance direct viewing into the beam must be prevented.

Throw ratio: 1.83 : 1Aspect ratio: 1.85 SP4K-15C

// separation height

Actual

1.88 m

Limit

2.00 m

Beam reaches into the audience space

// affected seats

seats total

1 rows in the hazard zone · 5 seats per row

// top view

Drag the projector to see the impact

Affected seatSymmetry balanceSafe seat

Blocked seats must stay symmetric about the light-cone axis - equal on both sides of the centre. If the projector position cannot be adjusted, an amber seat is added so the zone stays symmetric.

// side view

Light beamHazard zone

// hd vs throw ratio

Operating point: 1.8 : 1 -> 1.56 m

Orientation estimate based on the Barco model. Binding values come from the project documentation and on-site measurement.

DCI laser projectors are classified as risk group RG2 or RG3 under IEC 62471. The hazard distance (HD) is the minimum distance in front of the lens at which the laser beam no longer poses a direct hazard to eyesight. This calculator computes it for a specific Barco projector model and the entered throw ratio.

The result serves as input for the auditorium safety plan, placement of barriers and information signs, insurance documentation and reporting under local legislation. Always verify exact values for a specific installation with professional measurement.

The calculator uses parameters published by the manufacturer and the IEC 62471-5 methodology. Results apply to a standard configuration without an anamorphic adapter. With non-standard optics the hazard distance may differ.

How it works

Select the projector
Choose a Barco laser projector model from the list. Each model has a different laser source power, which directly affects the hazard distance.
Choose the region
Select US or outside the US. The American FDA/CDRH regulations impose a stricter limit, so the hazard distance for US venues may be longer.
Enter the throw ratio
Enter the lens throw ratio. A shorter throw ratio concentrates the beam and increases radiation density, which extends the hazard distance.
Review the result
The calculator shows the hazard distance in metres and graphically illustrates the hazard zone in front of the lens. Verify that walkways or technician work areas do not fall inside this zone.

Frequently asked questions

What is the hazard distance?: The hazard distance (HD) is the distance from the front of the projector lens at which the laser radiation density drops below the limit set by IEC 62471 for the relevant risk group. No unprotected persons may be present within this zone.
Why does the value differ for the US and other markets?: The American FDA/CDRH classifies laser projectors under its own methodology (21 CFR 1040), which is stricter than the IEC 62471 used in Europe and the rest of the world. As a result the calculated hazard distance for the US region is generally longer.
Do I need a safety plan even for a small auditorium?: Yes. Any RG3 laser projector requires safety measures regardless of auditorium size. Recommended measures include barriers in the hazard zone, a locked projection booth, information signs and a record in the operating documentation.
Does the calculator replace professional measurement?: No. The calculator is an indicative tool for designers and technicians. Binding values for a specific installation must be established by accredited on-site measurement, as the result also depends on the specific optics, laser condition and actual device output power.
How does the throw ratio affect the hazard distance?: A shorter throw ratio (wide-angle lens) concentrates the laser beam into a smaller cross-section and increases radiation density. That extends the distance over which radiation drops to a safe level. A telephoto lens conversely results in a shorter HD.

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