Seeing is believing. Or is it?
As out protagonist leaves the site of where the body was supposed to be, he comes across the group of mimes he interacted with the morning before. He witnesses the mimes transform from a rowdy group into exactly what we (and he) expect them to be. He is drawn into their world as he watches them mime a game of tennis. He even becomes part of their reality when he is asked to throw the lost ball back into the court. He indulges them, and himself, acknowledging his own perception of reality as he hears the ball actually being hit back and forth.
This is important because he has come to the conclusion that he has to believe what he can’t see through his camera lens. Everything that made the murder a reality has been taken away from him. The detail of the scene was lost as he blew up the photos. His photographic evidence was stolen, with the exception of a single blurry blowup that really reveals nothing. The body was removed from the park. He has to rely on what HE has seen to be true.
Perception alters reality. Perception defines reality. And Antonioni’s use of the camera and color in this film controls our own perception of Thomas’s experiences. We are drawn into his world. A world based on our own beliefs and values. Who are we to judge his actions when we are all guilty of framing our own perception of life?