ANSI lumens
The original 9-point method, standardised by ANSI. That standard is now historical/withdrawn.
- Unit
- lm
- Standard
- ANSI/NAPM IT7.228-1997 (historical)
- ISO 21118
- Extension
- Better
- ↑ Higher
- Mean illuminance
- 313 lux
- Image area
- 2.25 m²
- Light output
- 705 lm
- mean lux × m²
- Uniformity
- 62 %
- darkest Ă· brightest
Show the numbers
| Point 1 | 260 lux |
|---|---|
| Point 2 | 340 lux |
| Point 3 | 260 lux |
| Point 4 | 340 lux |
| Point 5 | 420 lux |
| Point 6 | 340 lux |
| Point 7 | 260 lux |
| Point 8 | 340 lux |
| Point 9 | 260 lux |
| Lumens | 705.0 lm |
| Uniformity | 61.9 % |
The 9-point method (IEC 61947-1, the basis of ISO/IEC 21118 light output and the old ANSI lumens): measure illuminance at nine points of a 3Ă—3 grid, average them, multiply by the image area. Uniformity here is the darkest point as a percentage of the brightest. ISO 21118 states production averages, and shipped units must reach at least 80% of the stated value.
How to compare it
ANSI lumens(lm)
From a major brand, close to the ISO method. From an unknown brand, treat it as 'claimed 9-point, unverified'. Never mix it with ISO in one sort without a flag.
Marketing traps
- ANSI lumens: 'ANSI lumens' printed on a Chinese marketplace listing often bears no relation to the method.
Across the catalogue
ANSI lumens
6 of 24 projectors list it- BenQ X3100i3,300 lm
- BenQ TK710STi3,200 lm
- Hisense PX3-PRO3,000 lm
- BenQ W58002,600 lm
- Nebula Mars 3 Air400 lm
Deep cut
ANSI lumens. Withdrawal left ANSI as a generic label. Its successor in practice is IEC 61947-1, which ISO 21118 references.
Terms on this page
ANSI lumens
From the withdrawn ANSI/NAPM IT7.228 (1997). You measure illuminance (lux) at 9 points of a 3×3 grid on a full-white field in the brightest calibrated-ish mode, average them, and multiply by the image area in m². "ANSI lumens" is still the most-cited term, even though the standard behind it is gone. ⚖ brightness.ansi_lumens ↑