OLED > 20 f-stops
As can be seen in the “peak brightness” section OLED cannot reach the same peak brightness levels as LCD but it can reach visibly deeper blacks. The ratio between these two (white and black) is called the contrast ratio and ‘dynamic range’ can help describe what lies between the two extremes. OLED can reproduce over 20 f-stops and can do so without introducing bleeding/clouding/blooming/halos. The dynamic range of any OLED TV in any price class is higher than the dynamic range of the best LCD TV.
LCD 8-17 f-stops
The dynamic range on a given LCD depends on the panel type and backlight implementation. The worst LCD TVs (that claim HDR support) can reproduce only 8 f-stops. The best LCD TVs with full array local dimming (FALD) can reach 15-17 f-stops, but not without introducing visible haloes around glowing object in contrast-rich scenes. The 15-17 f-stops number is a best-case scenario that the LCD can only reach for certain picture scenes. The best LCDs can reach higher peak brightness levels than OLED but are held back by the inability to reproduce true blacks. The more zones in an LCD, the higher the dynamic range.
The human eye is dynamic and can use pupil adaptation to perceive up to an incredible 46 f-stops of dynamic range. From an incredibly low brightness level of 0.000001 nits up to an extreme 100,000,000 nits level (Source)
’Dynamic range’ has many similarities to contrast but can be a better way to think about picture dynamics when discussing HDR. The dynamic range is not measured lineally but logarithmically. Every f-stop (or dynamic stop) is a doubling in light intensity.
Example:
- The difference between 16 to 512 nits is 496 nits in absolute terms, but 5 f-stops.
- The difference between 512 to 1024 nits is 512 nits in absolute terms, but only 1 f-stop.
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