Tarkovsky's Andrei Rublev has an extended sequence where a bellmaker's young son agrees to pour a bell for a local lord. You see the entire process of making the mould and pouring the metal. It has a town-fair atmosphere. But at the end, there's tremendous pressure on the young bellmaker to have the bell ring properly and have no cracks. And it does. The protagonist, the lapsed monk Andrei Rublev, regains his faith, seeing the result of the young bellmaker's hope.