TCL C8K is a really bright television. In synthetic conditions – that is, during tests with brightness charts – it was able to achieve even 3500 nits peak brightness in movie mode. That's an impressive result and brings the C8K close to the market leaders, at least when it comes to panel brightness. More importantly – these aren't just numbers on paper. In films with a lot of bright scenes, such as Life of Pi or The Meg, the brightness clearly exceeds 1000 nits, providing a true sense of HDR effect. The picture in those moments looks very dynamic, colors are saturated thanks to excellent coverage of the color palette, and the lights are – spot on and intense. Exactly how it should be.
However, this doesn’t mean that everything is perfect. Just like in contrast tests, here too, in more demanding scenes, compromises appear. In sequences with very fine light elements – such as stars in the night sky or reflections in dark rooms – the local dimming algorithm can… get confused. Instead of bringing those details up, the television sometimes decides to dim them significantly – down to around 300 nits – to maintain deep blacks. On one hand, this is quite a sensible approach (better deep black than a grey/navy blue screen), but on the other – there may be moments when certain elements of the picture become difficult to see or even disappear into darkness.
TEST UPDATE (20/08/2025): The brightness control algorithm in this model is quite problematic – attempting to calibrate the picture so that it doesn’t drastically overexpose the brightest scenes results in unnatural shifts: improvement in one part of the image results in deterioration in another. The television may achieve slightly higher readings in brightness measurements, but in practice, this comes with a heavily overexposed image that looks very unnatural!
For the record, we provide brightness values without this adjustment:
1463 nits
640 nits
1368 nits
468 nits
1025 nits
For most of the time, let's say in 90% of film scenes, viewers will hardly see any difference between the S85F versions. When small but very bright light points appear on screen – a lantern in a dark alley, a gunshot, the sun breaking through the clouds – this WOLED panel (just like the smaller S85F) performs exceptionally well. Our measurements showed a peak brightness of around 750 nits. We can confidently state: this is a great result that guarantees fantastic HDR effects. The problem arises in a very specific, uncomfortable situation for any OLED. We're talking about the moment when the entire screen has to shine at full brightness clearly. Examples include a white background screen, a skiing scene, or our test sequences (5) from the film The Meg. And here, unfortunately, the results diverge quite significantly against the WOLED panel variant. Our measurement equipment was able to measure a maximum of around 250 to 300 nits of brightness under such conditions. To be clear: the same model on a QD-OLED panel in the same test is almost twice as bright. The second issue: colours. And here we also have to be honest – QD-OLED has a structural advantage. Why? It’s simple. QD-OLED creates colours from three components (red, green, and blue) and doesn’t need an additional white subpixel. The WOLED panel we’re testing here uses that white subpixel, mainly to boost overall brightness. The effect is that QD-OLED is able to display a slightly wider colour palette, and the colours are a bit "cleaner." But let’s be clear: it’s not that the colours on this WOLED panel are bad! Quite the opposite, they are really very good. Coverage of the DCI-P3 film colour gamut at 97% and 71% for the wider BT.2020 palette is still high-end. We just have to honestly admit that those few percentage points of coverage advantage lie with QD-OLED technology and may be noticeable in very specific moments.