A 120-foot-radius sphere of inky darkness spreads out from a point you choose within range consuming light within its area. Within 60 feet of the point it is centered on bright light is reduced to darkness  and dim light or normal darkness is treated as magical darkness. Between 60 feet and 120 feet from the center of the effect bright light  is reduced to dim light and dim light is reduced to regular darkness.

You chose a point in range, an object you are holding, or one that isn't being worn or carried, the darkness emanates from that point or the object and moves with it. Completely covering an  affected object with an opaque object, such as a bowl or a helm, blocks the reduction of light.

If any of this spell's area overlaps with an area of light created by a spell of 3rd level or lower, the spell that created the light is dispelled.