ANSI (checkerboard) contrast
The average of the 8 white rectangles ÷ the average of the 8 black ones, on a 4×4 checkerboard. This is intra-scene contrast.
- Unit
- :1
- Standard
- IEC 61947-1 / ANSI 4×4 checkerboard
- ISO 21118
- Extension
- Better
- ↑ Higher
- No-room contrast
- 500:1
- illustrative
- Stray light
- 0.74 %
- of full white
- ANSI contrast
- 108:1
- Lost to the room
- 78 %
Show the numbers
| Image area | 2.25 m² |
|---|---|
| Room surface area | 102 m² |
| Black square (rel. to white) | 0.200 % native, 0.94 % with room |
The 4×4 checkerboard (IEC 61947-1 style) averages the white squares and the black squares and divides. Light from the white squares bounces off the walls and lands on the black ones. The room term is a diffuse inter-reflection approximation (Φρ ÷ A(1−ρ)) that assumes uniform walls and a screen that reflects all of its light, so treat it as a shape of the effect, not a prediction for your room.
How to compare it
Checkerboard (ANSI) contrast(:1)
The best predictor for mixed-content scenes and rooms with some light. Values cluster in the few-hundred to ~1,000:1 range whatever the on/off rating.
Room reflectance
How much light the walls, ceiling and floor return to the screen.
A white room can cut effective ANSI contrast dramatically. Dark surfaces near the screen do more for contrast than a better projector.
Standard: Editorial
Marketing traps
- Checkerboard (ANSI) contrast: Watch for two things: - Rarely rated. When it is, it's unverifiable. - The room caps it. A white-walled room returns light to the screen, so you see far less than the lens delivers.
Deep cut
Checkerboard (ANSI) contrast. Lens flare, internal reflections and veiling glare limit it. DLP often leads LCoS here despite much lower on/off. That's why 'DLP pop' and 'LCoS depth' are both real.