Artist use different techniques to make there drawings unique. which artwork demonstrates the use of the sfumato technique?

The second one is the sfumato technique

there are the initial camera costs, with each camera running about $1,000, but the storage costs are where the real expense comes in. according to a recent time article online, nearly a third of the 18,000 state and local police departments in the u.s. are purchasing body-cameras for their officers.