Air Lens

You create a 1 ft thick, 60 ft radius magical lens centered on a point you can see 100 feet directly above you, with which you can direct intensified rays of the sun against your foes. The lens must be in sunlight for this spell to function. If the lens loses contact with the sun (for example, if it is enveloped by darkness) it ceases to function until contact resumes.

When you cast this spell and as an action on each of your subsequent turns for the duration, you can hurl two rays of sunlight at a creature or object underneath the lens. You can hurl the rays at one target or several. You cannot target anything in an area of magical darkness. 

Make a ranged spell attack for each ray. On a hit, the target takes 2d6 fire damage. Any unattended, flammable objects hit by this spell will combust, taking 1d6 fire damage on each subsequent turn until they are put out. Optionally, you can target a piece of attended or worn equipment. Make the ranged spell attack with disadvantage (use the AC of the attending creature instead of the object's AC). If you hit, in addition to the normal damage of this spell, a flammable target will combust and take 1d6 fire damage on each subsequent turn until it is put out. Any creature holding or wearing a flaming object will take 1d6 fire damage per round until they drop the object (if possible) or put the fire out. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you create one additional ray for each slot level above 3rd.