Beam Divergence & Spot Size
Estimate laser beam divergence and spot size at throw so designers know whether graphics will still read from FOH.
- Predict spot size at real throw
- Compare optics before locking content
- Pair with scan-angle planning
Beam Divergence & Spot Size
Compute spot diameter versus distance. Supports full or half-angle and mrad or degrees.
Inputs
Most manufacturers publish full-angle mrad. If you only have half-angle, pick “Half-angle” and enter that value.
Results
- Distance (m)
- 20
- Full angle (rad)
- 0.0012
- Spot diameter (mm)
- 27
- Spot diameter (in)
- 1.063
- Spot area (m²)
- 0.0006
This is a geometric estimate. It does not assess eye safety or MPE. Use certified methods for audience scanning evaluations.
Quick look: common distances
| Distance (m) | Spot dia (mm) |
|---|---|
| 10 | 15 |
| 20 | 27 |
| 40 | 51 |
| 60 | 75 |
| 100 | 123 |