The U7S Pro in the 65" version we tested uses a VA panel and has as many as 960 local dimming zones. Thanks to the combination of this panel (that is, with high native contrast) and the large number of zones, blacks here are really very good. In dark scenes viewed with the room slightly lit, the effect can even resemble OLED TVs with organic panels, as our first test scene from the film Oblivion showed. Unfortunately, when the screen contains more small bright elements on a dark background, the local dimming algorithm begins to show its weaknesses. Contrast can then drop noticeably, and a halo effect, a characteristic glow (so-called blooming), becomes visible around bright objects. This is, however, a natural feature of Mini-LED TVs caused by the physical limitations of this technology — there will always be fewer dimming zones, even if there are many, than independent pixels in an OLED, so it is physically impossible to eliminate it completely. Interestingly, although the new U7S Pro model has almost twice as many local dimming zones as last year’s U7Q Pro, in practice it has not brought any significant improvement in this respect.
Moving on to picture quality tests, it is immediately apparent that the biggest change the TCL A400 Pro brings compared with typical lifestyle TVs is in blacks and contrast. This is all down to a full Mini-LED backlight placed directly behind the panel. As a result, the TV can locally dim selected parts of the image and is not limited solely to the native contrast of the panel. In the 65-inch sample we tested, we counted 180 dimming zones. That is not an impressive number compared with conventional Mini-LED TVs, where zones can be many times more numerous, but for a lifestyle TV it is already a very large step forward. Especially as competing models often either lack advanced local dimming or use much simpler edge-lit backlights.
In practice this produces very good results. In simpler scenes, where bright elements are clearly separated from a dark background, the A400 Pro can effectively dim the black areas of the image and show genuinely deep black. It is one of those things that immediately sets it apart from many conventional “picture” TVs. Of course, this does not mean TCL entirely avoids the limitations of Mini-LED LCD technology. 180 zones is still relatively few, so in more complex scenes, for example those with many small bright elements on a dark background, a halo effect can appear. It can also happen that blacks take on a more navy‑blue to purple tint in such conditions, because the TV cannot dim the background with the same precision as OLED TVs. Despite these limitations, we believe the A400 Pro brings a genuinely fresh breath to this category. For a lifestyle TV, which is primarily intended to look good on the wall, the level of blacks and contrast is a very strong selling point.
NOTE. It is worth noting that the number of local dimming zones depends on the screen diagonal. Larger variants should have more, but because the number of zones increases with panel size, we do not expect large differences in black level and contrast between the Mini-LED versions. The exception are the 32- and 43-inch models, in which TCL did not implement local dimming. These are significantly simpler LCD designs, so our review does not directly apply to those diagonals, and the prices quoted with the review should be treated as indicative only.
Number of dimming zones in the TCL A400 Pro
Screen size | Backlight type | Number of local dimming zones |
32" | PFS LED | No local dimming |
43" | PFS LED | No local dimming |
55" | QD Mini-LED | 112 zones |
65" | QD Mini-LED | 180 zones |
75" | QD Mini-LED | 240 zones |
85" | QD Mini-LED | 264 zones |
98" | QD Mini-LED | 448 zones |