@wolfofx The lower can subtracts from the overall distance measured, the upper can adds to the overall distance. So if distance measured without cans is 10 and the can is 2x4: 10-2+4 = 12 and 10-4+2 = 8.
@ashtonforbes If you think the footage is gorgon stare - filmed by a drone - why is there no movement relative to the clouds visible like in the IR video?