The Dreame S100 is a Mini-LED television that uses an IPS/ADS panel in its 65" version. Such a panel does not inherently offer the best contrast on the market; however, thanks to the fairly dense Mini-LED backlighting, the black level in this model is actually quite decent. In less demanding scenes, the contrast was able to 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 level and contrast in the S100 will be quite appealing for a less demanding viewer.
Unfortunately, in more demanding scenes, where a considerable amount of small elements appears on a black background, the local dimming algorithms in the Dreame S100 do not operate perfectly. The television may either darken excessively, making the black level extremely deep but rendering almost nothing visible on the screen, or it may go in the opposite direction—showing a large number of details but resulting in very poor contrast. The black level in very demanding scenes around bright objects takes on a greyish hue (halo effect). This is a typical limitation of Mini-LED televisions in the lower and mid-range, and unfortunately, the Dreame S100 is not an exception that handles this problem particularly well. However, it should be noted that, overall, the contrast and black level here are at a significantly better level than in LCD televisions without any local dimming technology.
TCL C7L is a Mini LED television, which in the 65-inch variant we tested, is equipped with over 1000 local dimming zones. This, combined with the proprietary VA panel (referred to by TCL CSOT as HVA 2.0), yields truly decent results in terms of blacks and contrast. In most of the scenes we measured, the black levels and contrast looked really good, and in the easiest shots, the black was deep enough to almost resemble that seen on OLED screens. Of course, we are talking about the least demanding shots with a lot of black on the screen. However, when a greater number of bright elements appear on the screen and black no longer dominates as strongly, it is apparent that the TCL C7L – like most Mini LED televisions – has its issues with managing local dimming zones.
This is particularly evident in the black bars in films recorded in the 2.35:1 widescreen format. At that point, a distinct halo effect, or bright light glow, can appear on the black bars or around small, bright objects. 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 is worth remembering that this should not be treated as a flaw of the television, but rather as a characteristic of mini-LED technology. Of course, this effect becomes significantly less bothersome when we turn on at least some soft, diffused light in the room... which I definitely recommend doing during screenings on any LCD television.