The Dreame S100 is a Mini-LED television that features an IPS/ADS panel in its 65" version. This type of panel doesn't inherently offer the best contrast on the market, but thanks to a fairly dense Mini-LED backlight, the black levels in this model are actually quite impressive. In less demanding scenes, the contrast can reach values of 30,000:1. This is a result several times higher and practically impossible to achieve for any type of LCD panel without local dimming technology. This means that the black levels and contrast in the S100 will be quite appealing for the less demanding viewer.
Unfortunately, in more challenging scenes where a considerable number of small elements appear against a black background, the local dimming algorithms in the Dreame S100 don't perform perfectly. The TV can either dim excessively, making the blacks really deep but rendering almost nothing visible on the screen, or go the other way – showcasing a vast amount of detail, but resulting in very poor contrast. The blacks in very demanding scenes around bright objects then take on a greyish hue (halo effect). This is a typical limitation of Mini-LED televisions in the lower and mid-range segments, and unfortunately, the Dreame S100 is no exception, doing particularly poorly in this regard. However, it should be noted that overall, the contrast and black levels here are definitely better than those found in LCD televisions without any form of local dimming technology.
TCL C7L is a Mini LED TV, which in the 65-inch variant we tested, is equipped with over 1000 local dimming zones. This, combined with the proprietary VA panel (called HVA 2.0 by TCL CSOT), delivers really decent results in terms of black levels and contrast. In most of the scenes we measured, the blacks and contrast looked really good, and in the easiest shots, the black was deep enough to almost resemble that seen on OLED screens. This is of course referring to the least demanding shots with a lot of black on the screen. However, when more bright elements appear on the screen, and black stops dominating as much, it is evident that TCL C7L – like most Mini LED TVs – has its issues with local dimming zone management.
This can be clearly seen, for example, on the black bars in films shot in the 2.35:1 panoramic format. Then, on the black bars or around small, bright objects, a pronounced halo effect, or a bright light glow, can appear. The contrast then drastically dropped – from laboratory values of around 200,000:1 to about 10,000:1, which is quite noticeable in a completely dark room. It’s worth remembering that this shouldn’t be treated as a flaw of the TV but rather as a characteristic of mini-LED technology. Of course, this effect becomes much less bothersome when we turn on at least some light in the room… which I definitely recommend doing during screenings on any LCD TV.