Aug 26, 2023 05:47 PM By Mr_Ballstone

6

Yes I see what you mean w/o local dimming but I still wonder if the local dimming algorithm still has some part to play in small highlights being intentionally dimmer. On a tv with considerably less dimming zones, the x90l, the small windows considerably exceed the 100% brightness window. This leads me to believe the relatively low highlight brightness on the q7 is due to more than just not having enough zones. I guess there isn’t really a way to test this but. Still food for thought.

Yes its a design choice depending on whether the manufacturer decides what is better or worse. Having the panel maintain its brightness to lower window sizes will increase blooming and related local dimming artifacts, so often to avoid it they will lower the brightness. A form of ABL (automatic brightness limiter) on top of local dimming but for a different reason. But then you of course affect the peak brightness which is another problem, so balancing between the two is determined by the manufacturer for how they feel its best.

Changing the local dimming setting to low on the Q7 will actually give higher brightness with smaller windows, but i think it affects other factors such as reduced brightness at larger windows and perhaps lower dynamic contrast.

Aug 26, 2023 04:30 PM By Mr_Ballstone

6

It would be interesting to see how HDR brightness scores with local dimming disabled. I’ve noticed with mine that small highlights are severely darkened with local dimming on (presumably to prevent blooming). This would explain the large dip in brightness for small windows.

Basically it would be the same as the 100% window values accross all window sizes, as local dimming only works to improve brightness in different dimming zones by concentrating power to zones instead of the entire LED array. Which is why you will typically see the brightness levels increase as the zone size decreases when local dimming is enabled. Until it reaches a zone limit where the window size is smaller than the zone size capable with the allowcated zone count. Which is where you see the brightness decrease around 10% - 20% window size as there are not enough zones to accomodate the small window area.

Basically local dimming off would show 565cd/m2 accross all windows for the QM7.

Aug 25, 2023 11:49 AM By  Simon Barbier

Hello DANOFDANGER, we don’t have that data. Although in theory, it could be a good idea to give us an idea of how well the room correction system performs, we would need to test it in a few different rooms to have a large enough sample size to be useful. Even a single pre-measurement would take us several hours as it is time-consuming to average a room’s response with 48 distinct positions in the room. We prioritize using that time to test more products to help you guys make a better purchasing decision.

Thanks for the response, yes it would be interesting but i don’t think you would have to do multiple rooms to get “some” useful information depending on how much it compensates for your current test room. I have purchased recently the sony HT-A3000 and then after wanting more, subscribed here and started looking through your data and running measurements of my own using umik-1. Then proceeded to purchase the bose 900 but ultimately returned it because its midrange prior to calibration was aweful and the room EQ was not good enough to compensate for it. Will be looking at maybe the 990c from samsung next as thats the only soundbar that respectively follows the midrange of the harmon curve but also importantly the entire frequency response.

Is there any frequency response data for the soundbar when used without using the room correction feature ?. Curious to know what its like before and after room correction.

Aug 16, 2023 04:33 PM By skyescheschuk

14

Well they need to get their act together because even Hisense has no visible smearing or overshoot with VRR. TCL is the only brand I’ve encountered it

Yeah i don’t deal with the issue because even with that fixed, the original VRR flicker remains and the only way to avoid that is by turning off VRR or making sure game frame rates are stable with very minimal 0.1 or 0.01% lows that don’t breach the LFC barrier. So it really doesn’t matter until they fix that, which is a hardware level issue.

Aug 16, 2023 03:54 PM By skyescheschuk

14

I didn’t say it was happening because of the VRR, but TCL designed this TV to overdrive when VRR is on. All they have to do is make the response time not change when VRR is switched on compared to off. That can be done at software level. I’m willing to bet having overdrive with VRR was intentional, but it just gives unwanted side effects.

I still don’t understand what you are trying to say sorry. But in any case, overdrive with VRR is quite common and required as it introduces response time issues (significantly more smearing and ghosting). Its required in order to maintain ideal response times. Which is why if you read the rtings articles on the QM7/8 they discuss how the TCL’s overdrive is not done thoroughly enough and in “brackets” instead of consistently throughout the entire refresh rate range. So we actually in fact need more overdrive to fix things, not less.

I mean no disrespect by the way.

Aug 16, 2023 01:49 PM By skyescheschuk

14

That applies to slow response time usually. But this is overshoot, which could be fixed with software. It’s obviously possible to get rid of it, as when VRR is off there’s no overshoot at all, but as soon as you turn VRR on everything leaves a huge inverse trail. On the very similar model, C725, it can be fixed by turning off quick start, but not on the Q7, so it’s definitely software. On things like gaming monitors, it’s also not an issue if you keep overdrive low or off depending on the monitor. The point of overdrive is to introduce overshoot to keep moving objects on screen more clear at the cost of inverse ghosting. What thr Q7 does is force overdrive when you’re in VRR.

The cause of VRR flicker is caused by voltage fluctuations as the panels refresh rate moves further away from its native frequency. These voltage fluctuations cause slight shifts in brightness as the frequency changes, so slight in fact that its only really noticeable in dark situations. As our eyes are naturally the most sensitive in this region. This issue which plagues all display types but some more than others (for example OLED), is not caused at all by pixel response time or overdrive artifacts. Overdrive has been around far before VRR was around. I remember using it in the 2000s on early LCD displays and yes, inverse ghosting was something we had to deal with on the daily if we wanted better response time. But this did not cause flicker. This is a entirely new isssue we have not had to deal with (ignoring PWM flicker) until VRR come along and “unlocked” the fixed native frequency to allow a dynamic refresh rate of the display.

You could theoretically fix this in software but at the core its a hardware first problem and trying to solve it on software would be insanely compute expensive and difficult, as you would need to change the gamma curve at every frequency to compensate for the voltage sag or rise that occurs and each display would require its own unique configuration for it. It would be much easier to just fix it at the hardware level.

Aug 15, 2023 09:45 PM By skyescheschuk

14

I doubt it will be fixed, at least the response time. The R646, two models old, has the problem and it never got fixed. I also brought up a case about it with TCL, kept getting told that my videos didn’t show the issue well enough when they certainly did, then they closed the case. I really wish I was still in the return window, its just problem after problem with this set.

Its a hardware issue more than a software issue, software could help resolve it but it would mean a lot more processing and coding to compensate for these artifacts. Not something that will likely be done. Its a common issue with VA panels and you get it even with gaming monitors, not a lot that you can do to mitigate it.

Aug 15, 2023 07:25 PM By  Pierre-Olivier Jourdenais

Hi! Indeed, the TV’s Game Mode PQ EOTF tracking test, as shown in the review, was taken with HGiG enabled. It’s actually common for TV manufacturers to overbrighten the TV a bit in Game Mode; this is likely due to the perception that gamers would rather have their TVs ‘pop’ than be accurate. Also the idea of respecting the creator’s intent is a bit more nebulous for games when compared to movies, so TV manufacturers take more liberties. But yes, that graph for Game Mode under the PQ EOTF tracking text box was taken with the HGiG toggle enabled.

Thanks good to know.

This raises a question for me, what tone mapping were they using for the HDR tests. Was it off, detail, balanced or brightness. I assume it was off as that is the only one that clips at the panels peak brightness.

Aug 15, 2023 03:21 PM By  Pierre-Olivier Jourdenais

Hi! Sorry I made a mistake; both the Q7 and the QM8 have HGiG. I talked to our testers and both TVs were tested with HGiG enabled, and it’s definitely what we recommend for gaming. As a rule of thumb, if the TV has HGiG, it’s always what you should go for if you care about image accuracy. Sorry again! Hope this clears that up a bit.

I think you might be mistaken again or i am misunderstanding you. Hgig would not have been tested in the review with hgig enabled as its a game mode only feature and not available under the movie presets which is what is stated to be used. They also did a seperate game mode eotf test and showed that game mode was less accurate as it followed the ideal curve less.

If they did indeed test hgig i would be very interested to see that transfer function graph.

Aug 15, 2023 12:31 PM By skyescheschuk

14

Yet another issue with this set. When I have the 20 point calibrated in HDR, and I go to SDR, and then back to HDR again, the colors are all way off, all purple and stuff. I have to switch 20 point off and back on again to fix it. This TV has so many issues that TCL just doesn’t care to fix, even when I bring up a case about it.

Also seems to happen in game mode. I have to turn game mode off and calibrate there and then apply the settings in game mode to ensure it sticks. Every time you go to change something in 20 point, it shifts the enitre settings to something else and completely throws it off.

Aug 15, 2023 01:23 PM By  Pierre-Olivier Jourdenais

Hi! TCL doesn’t support the HGiG standard in their TVs; so for the Dynamic Tone Mapping feature you can only set it to On or Off. Of the two, Off tends to be the most accurate; On overbrightens the TV, and the Q7 is already a tad overbrightened across the board in Game Mode with Dynamic Tone Mapping to Off, so it’s even worse with it On. So if you want the best accuracy while gaming on your Q7, Dynamic Tone Mapping to Off is the better option.

In the game menu when you hold down the regular menu for 4 seconds there is the option to enable hgig, which seems to only disable the dynamic tone mapping setting in the other settings menu.

Aug 15, 2023 10:34 AM By ivankai29

7

I can see that. The calibration settings they posted seem to help skin tones but idk if it’s better overall. There is no one here, where i live, to callibrate it and aside from basic tools I don’t think I could callibrate it better myself. Maybe on pc mode only but pretty heavily rely on rtings settings. Even with hdr sdr and Dolby content I don’t know which white points are best or correct. If they didn’t specify an hdr 2 point then I would just assume they ones at the bottom were across all settings.

Calibration isn’t the answer, its a issue that needs to be fixed by software to allow correct color space selection. You shouldn’t have a problem with this in hdmi though. Its only youtube and sometimes netflix/disney that i have experienced a color space problem. Don’t mess with the calibration trying to fix it as you will only make it bad when the system actually chooses the correct color space in other video content. Because it changes all the time. So like i said, go into expert calibration settings and set it to custom for sdr (default settings only) and native for hdr. And for dolby vision theres a trick to toggle the color saturation up and down to flick it to the right color space since you can’t select color space there.

There are a lot of bugs in this tv.

Aug 14, 2023 05:19 PM By Cool-Spot

6

Is the American Q7 similar to the European C745? I wanted to buy a C745 (france) but there is very little test here. After reading your test I ask myself questions… is it really that good?

Its similar but i don’t beleive its exactly the same. I have the c745 but based on the results of the q7 review they don’t seem to be “exactly” the same. For example my old Q70a and nu8000 both had around 550 nits brightness at full window (no local dimming). And the c745 is considerably brighter by a large margin. I estimate around 800nits minimum and 1000 nits peak with local dimming. But other than that i beleive the panel is the same and just different LEDs used.

Aug 14, 2023 09:42 PM By ivankai29

7

How did you set the white point calibration. You only list 2 point for HDR. Did you not need the 20 point? I have had the TV after up(down)grading from my LG C9 and the colors have been terrible. I started getting used to them but using the YouTube app was just insanely red and skin tones were terrible. I saw the 2 and 20 points at the end but idk if those were global or just sdr. The 2 point at the end was different from the 2 point for HDR. Curious if Dolby vision didn’t need white point adjustments? It all seems a little confusing andI would like to compare to your settings because the colors just feel wrong. I tried inputting the white points across all settings but it does seem excessively warm or red when watching hdr and Dolby content but turning 20 point off and just using 2 point looks excessively green. I dont know if it’s my TV, but if I could figure out your white points to apply them correctly for the different video settings, it would help me determine what to do with this TV. I was hoping for more from this TV. I went from 55 to 65 inches so this is much nicer for the room, but it’s hard to compare color to an OLED. The viewing angle is also terrible, even comparing it to other VAs. I feel like if I move more than 20 degrees the colors all shift.

The youtube issue you are dealing with is a color space issue that clamps the color space to the wrong one. Its annoying but doesn’t happen on all youtube videos. Try changing the color space to custom to attempt locking it to the correct one and then native for hdr content. But for me it didn’t work and still incorrectly applied the color space, its frustrating.

Hi, i purchased this after subscribing as a insider which helped me make the right decision. I just wanted to know if there was any testing of what the voice setting does exactly and hpw it affects the frequency response.

Aug 11, 2023 02:36 PM By jokingrofl

2

Could you explain what you mean by “having its refresh rate function in brackets”? Also I’ve noticed on my Q7 that gaming with an Nvidia GPU (with VRR and G-sync on) that the TV has brightness flickering when the FPS changes, is that something you guys have noticed in your tests as well or could I have received a defective unit? Many thanks!

VRR flickering happens to a lot of VA panels, all my past TVs have done it. The NU8000, Q70A and now the Q7. Though to a lesser extent. Its made worse with LFC when frames drop below 48 it will instantly multiple the frames to keep it with the VRR range and the sudden shift causes intense flickering as it jumps back and forth between LFC. I opt to turn it off and just use vysnc at 120hz, the high frame rate keeps the latency low enough for non competetive games.

And just to let people know, you can actually get 144hz working with nvidia cards if you copy the profile settings that is in the EDID and make a custom resolution in the nvidia control panel.

Aug 08, 2023 02:16 AM By Dimon_Zorg

53

QM8 has panel with high native contract so it is not the case here..

The QM8 actually has half the native contrast of the QM7 5000:1 compared with nearly 10,000:1.

Aug 07, 2023 10:28 PM By Dimon_Zorg

53

Considering huge difference in number of dimming zones SLIGHTLY higher score is advantage for Q7 actually

Having more dimming zones does not mean it will always be better at preventing local dimming artifacts. Its actually a combination of zone count, native contrast and the local dimming algorithm. Quite often manufacturers will use poor native contrast panels when combined with high zone count systems, as they can compensate the poor native contrast with better local dimming. But this has a negative affect on artifacts such as blooming as light is easier to bleed around objects such as bright text. If a display such has high native contrast than a unit with more zones, it could potentially still be better at preventing blooming if the native contrast is poor on the same display with more zones. I agree that the Q7’s blooming is very low. I actually never use local dimming because blooming always just sets me off no matter i notice it in real usage or not. I like accuracy over processing techniques that try to dynamiclly improve the display at the cost of theoratical accuracy. This is the first time i have turned it on because i actually can’t notice it in testing in pitch black environment. I suspect this is a result of the really high native contrast.

Aug 02, 2023 10:47 PM By larryww80

1

Really ready to see this review, have an older TCL 6 series and also a Samsung 2018 curved Q70 and it’s amazing (in fact it’s my primary PS5 TV and all) but looking to upgrade to affordable 120hz , this one seems to be nice but need more reviews before , so please

I had a q70a and loved it, would still have it if i didn’t have to downsize because of moving house. So got this TCL and was worried it wouldn’t compare. But i can say without a doubt that the TCL is better in every way. Except for maybe the static contrast, but its local dimming is exceptional and with it on low, is much better.