I’d never seen Mr. Peck, except in films, and when I saw him at my home I wondered if he’d be quite right for the part. The next time I saw him was in Hollywood when they were doing wardrobe tests for the film. They put the actors in their costumes and slam them in front of the camera to see if they photograph correctly.
They did Mr. Peck’s test on the lot on the little street where the big set had been erected, and the first glimpse I had of him was when he came out of his dressing room in his Atticus suit. It was the most amazing transformation I had ever seen. A middle-aged man came out. He looked bigger, he looked thicker through the middle. He didn’t have an ounce of makeup, just a 1933-type suit with a collar and a vest and a watch and chain. The minute I saw him I knew everything was going to be all right because he was Atticus.
-Harper Lee on Gregory Peck as Atticus