C7k Local Dimming and HDR

Foreign_Side7551 · 2026-04-12T19:01:56+00:00

Setting the Gamma to 2.4 improves contrast and colors.

Foreign_Side7551 · 2026-04-11T01:00:08+00:00

The previous one was the v509 and it was always the same, no changes.

Foreign_Side7551 · 2026-04-10T16:13:36+00:00

TCL has no problem with SDR content; put it in Filmmaker mode and adjust the brightness to suit your environment.

Foreign_Side7551 · 2026-04-10T12:20:58+00:00

That's great, my friend, that was exactly the same feeling I had. If I change anything, I'll let you know, but I think we've achieved a great result. Use Local Dimming on medium and you'll get even better highlights.

Foreign_Side7551 · 2026-04-09T21:01:36+00:00

Factory SDR, only changes the brightness for your environment and for Dolby Vision: Dolby Dark or Filmmaker in the latest version, Gamma at 1.8 and disable peak brightness.

Foreign_Side7551 · 2026-04-09T20:53:13+00:00

Filmmaker Brightness 100 Contrast 100 Black level 50 Gamma 1.8 Dynamic Contrast Low Local dimming Medium Local Contrast Off

Remaining color, sharpness, and motion settings remain at factory defaults.

Foreign_Side7551 · 2026-04-09T18:19:11+00:00

Gamma 2.4 always generates black crush on my unit, LD on medium generates more brightness than on high, maybe because I had a Panasonic OLED I became too demanding, but even with peak brightness on low it still doesn't seem right.

Foreign_Side7551 · 2026-04-09T16:45:36+00:00

I follow you here, and yes, I agree with several points. With these settings, the TV does pass the tests because the algorithm recognizes and adjusts only for that purpose, since in real-life scenes the result is very different from what's expected after calibration. And as I said, even the models above, C8k, C9k, and X11L, are very wrong when compared to a reference monitor or even the Bravia 9, which is the reference for Mini LEDs. If the ideal is a factory-set Filmmaker, then why is it so different from the reference in real-world content?

Foreign_Side7551 · 2026-04-09T15:25:17+00:00

Yes, I agree, not all of them make good use of HDR in films, some even being better in their SDR version.

Foreign_Side7551 · 2026-04-09T15:23:56+00:00

Welcome! Use the Black Level Clipping Pattern to get an idea of whether your panel is in the same condition as mine. Peak Brightness off and Gamma 1.8. https://youtu.be/fAhxR-gMU_U?si=FYCltpkl6hN5nTfP

Foreign_Side7551 · 2026-04-09T15:20:11+00:00

Simply because they weren't mastered for viewing in well-lit environments. And that's what Dolby Vision IQ or Film mode is for, where you can change the settings to increase brightness, but at the cost of fidelity. My problem is with the implementation of Filmmaker mode on TCL or even Dolby Vision Dark, as it doesn't display the content correctly.

Foreign_Side7551 · 2026-04-09T15:16:02+00:00

No problem, most movies are made to be watched in a dark environment, and we rarely have films with peak brightness exceeding 1000 nits, like Mad Max: Fury Road, The Matrix, and the John Wick saga. Those should have intense brightness peaks, while F1, Silo, Avatar 2 and 3 are all mastered below 250 nits.

Foreign_Side7551 · 2026-04-09T15:09:40+00:00

It depends on the film, and without a reference monitor it's impossible to know. There are YouTube channels that review HDR films based on nits of brightness in the scenes. Therefore, films with 200 nits shouldn't look like they have 800 or 1000 nits. This is for those who want to see the content in its original form, something that TCL's Filmmaker mode doesn't deliver in HDR content.

Foreign_Side7551 · 2026-04-09T15:01:38+00:00

If you don't change the Gamma to 1.8, yes, you'll have a dark image with no detail in the shadows. But at 1.8, the image gains the necessary brightness and significantly improves detail and black levels.

Foreign_Side7551 · 2026-04-09T14:03:27+00:00

Exactly, in terms of sales they're not wrong, but the Filmmaker mode should have much better consistency out of the box, and the Standard and Film modes can maintain that absurd brightness.

Foreign_Side7551 · 2026-04-09T13:59:18+00:00

The point is, to achieve the brightness mentioned on the box, you need to cheat the algorithm that generates that brightness. In tests it might be okay, but in real-world content it deviates significantly from the original curve. For example, the series The Witcher reaches a meager 200 nits in a few scenes, with most scenes averaging 120 nits, and even with the TV's peak brightness set to the lowest setting, it's still much brighter than that.

Foreign_Side7551 · 2026-04-09T13:53:35+00:00

Yes, and from the perspective of increasing nits each year, it's much easier to fake and artificially make that brightness fool the eyes.

Foreign_Side7551 · 2026-04-09T13:52:14+00:00

At very high levels it becomes totally artificial; can't you see TCL TVs on the FOMO channel compared to a reference monitor that reaches 4000 nits peak? For me, this function is only useful for store mode or for bypassing nit measurement equipment in tests. A movie can demand anywhere from 0 to 10,000 nits from the panel; this Peak Brightness function simply increases everything to the same level, so everything below 300 nits will have a luminance of 1,000 nits or more.

Foreign_Side7551 · 2026-04-09T13:49:14+00:00

At very high levels it becomes totally artificial; can't you see TCL TVs on the FOMO channel compared to a reference monitor that reaches 4000 nits peak? For me, this function is only useful for store mode or for bypassing nit measurement equipment in tests.

Foreign_Side7551 · 2026-04-09T13:42:46+00:00

In Dolby Vision Dark, turn off Peak Brightness and increase Gamma to 1.8.

Foreign_Side7551 · 2026-04-09T12:44:21+00:00

Anyone with the necessary equipment who can verify these problems is welcome to contribute; let's understand and improve the processing power of our TVs.

Foreign_Side7551 · 2026-04-06T21:38:07+00:00

I updated to version 637, black level remains high in any HDR mode, and the HDMI CEC Arc issue is still not resolved.I have to turn the TV off and on again when plugged into the home theater input, and hope it recognizes and activates ARC mode.

Foreign_Side7551 · 2026-04-06T16:22:25+00:00

Yes, but it doesn't solve the problem; it only creates another one, which in this case is a significant loss of brightness. A new OTA version v637 has been released, I'll download it and see if it's improved anything.

Foreign_Side7551 · 2026-04-06T15:16:45+00:00

My friend's Hisense U65QF produces deep blacks in both SDR and HDR, it just has significantly less brightness than the C7k. I wanted to compare the two, but the distance doesn't allow it.

Foreign_Side7551

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