Minecraft wiki entry for Light, associated text: In Java Edition, when calculating lighting, the shapes of some blocks are detected: pistons, daylight detectors, enchanting tables, farmland, lecterns, stonecutters, dirt paths, snow, end portal frames, slabs and stairs, so that the light passing through them can spread only in specific directions. For example, dirt paths prevents the light from propagating downward, but the light can propagate in other directions.