Recent advances in TV technology have resulted in flat panel displays that offer extraordinary contrast and brightness. The latest TVs excel at creating captivating imagery, even in rooms with ambient light—which is how most people watch TV. Under these conditions, no display can offer “infinite” black. Even when pixels are shut off completely—as with OLED—the light from the room raises the black level of the screen.
Before the introduction of OLED, TV makers competed to create the deepest blacks possible. In other words, increases in contrast weren’t achieved by boosting brightness; typically they came from deepening black levels. But when consumer OLED arrived, that race ended, since the technology allows individual pixels to be completely shut off.
Back to ambient light. The real-world contrast ratio of a display depends on several factors. Yes, black levels—as measured in darkness—still do matter. However, unless you primarily watch movies full of dark scenes (horror, film noir, space adventures), and always turn off all the lights, brightness and color volume are at least as important.
According to the U.S. Department of Energy, typical indoor ambient light levels are 125 lux by day, 70 lux in the evening, and 50 lux at night. As a point of reference, direct sunlight is 10,000 lux, bright office lighting is around 350 lux.
Granted, there will always be cinephiles and videophiles who will watch content in the dark (I strongly recommend front-projection if that sounds like you). However, I’ve found the majority of TV consumers expect to watch cable shows, stream Netflix, enjoy sports and play video games on their displays. Handling movie-watching in the dark is a small part of what most people look for, so it really shouldn’t be the primary determinant in a cost/benefit analysis.
Thanks to the demands of HDR, the new race is toward brighter and more colorful TVs. Peak luminance and high color volume are crucial parameters. These are the areas where QLED TVs and LED-phosphor models—both transmissive LCD TV technologies—shine.
Because transmissive displays create pixels by using a backlight in combination with an LCD panel to selectively block that light, they are not bound by limitations such as a loss of color volume. The end result is that images will appear to have more “pop” on these TVs.
Notably, today’s OLEDs still struggle to reach the 1000-nit mark, which is the peak luminance a lot of HDR content is mastered to. Furthermore, they can only achieve this in a tiny part of the screen, to the tune of 3%. By comparison, top-tier transmissive TVs are able to generate peak luminance levels well past 1000 nits, and do so over a much larger part of the screen (10% or greater). Additionally, because they don’t depend upon a white subpixel to achieve that peak luminance, colors stay bright and punchy.
A casual consumer who stumbled upon a discussion within an AVS Forum thread discussing these issues would be forgiven for thinking it was a life or death matter, and that the differences in performance between various TV technologies are of monumental proportions. Fortunately, this is not true.
For example, when I’ve seen side-by-side comparisons between a Samsung QLED and an LG OLED, or a Vizo P-Series XLED and an LG OLED—even in a totally dark room—the differences are not very pronounced. Extremely bright or dark scenes are the exception; with dark material, the OLED often look best, but with bright content, the transmissive displays look noticeably superior.
Regardless of which technology is used, there’s a lot to love about how TVs are evolving. Prices are dropping, screen sizes are growing, HDR content is proliferating. And thanks to improvements in brightness, color volume, and ambient light black levels, today’s displays perform better than ever. The key is to find the one that best suits your wants and needs.