Ambient light and contrast
The light falling on the screen from the room.
- Unit
- lux
- Standard
- AVIXA V201.01 (ISCR) context
- ISO 21118
- Context
- Screen white
- 234 cd/m²
- Ambient adds
- 15.9 cd/m²
- System contrast
- 15:1
- Kept
- 1.5 %
- of 1,000:1
Show the numbers
| Image | 2.20 m wide, 16:9, 2.72 m², gain 1.00 |
|---|---|
| Native (illustrative) | 1,000:1 |
| Formula | L_white = lm × gain ÷ (π A); L_ambient = lux × gain ÷ π |
No AVIXA category bands are drawn. ANSI/AVIXA V201.01 (ISCR) defines four viewing categories (passive viewing, basic decision making, analytical decision making, full motion video), but we could not verify its minimum ratios from a public source, so we do not show numbers we cannot cite. The native contrast and the ambient levels here are illustrative.
How to compare it
Ambient light(lux)
Drives the required projector output. Ambient light adds to black and so destroys contrast directly: ISCR is the projector's contrast as seen in the room.
ISCR viewing category
AVIXA's four viewing-requirement classes for image system contrast ratio.
Powers our 'how bright do I need?' calculator. Read the minimum ratio for each class from the standard before publishing numbers.
Standard: ANSI/AVIXA V201.01:2021
Deep cut
Ambient light. System contrast = (projected white + ambient) ÷ (projected black + ambient). Even 5 lux on a gain-1 screen adds ~1.6 nits to black, dwarfing the native black of any projector.
ISCR viewing category. The standard applies to all display types, not just projection, and replaced the older INFOCOMM 3M-2011 PISCR.