Contrast Test

In short This shows near-black and near-white step wedges, and what you are checking is whether your display is losing detail at either end. If the first four dark steps all look identically black, the display is crushing shadow detail — raise the black level or brightness control, and check whether the graphics driver is sending a limited range signal, which is the frequent cause. If the brightest steps merge into one white, highlights are clipping, and the contrast control is usually too high. Both faults hide detail that is present in the content, and both are usually settings rather than panel limits. One result that is not a fault: pure black looking grey rather than truly black. That is backlight leaking through the liquid crystal, it is normal on IPS, and it is unavoidable on any LCD — the crystal blocks light but never blocks all of it. Only OLED produces a genuinely black black, because an OLED pixel that is off emits nothing at all. A grey black on an LCD is the technology, not a defect.