“The Irishman” is competing against eight other movies for one of the film industry’s highest awards: the Oscar for best picture. When that award is announced in February, many people may pay close attention to the special effects teams that make it and similar films possible. Martin Scorsese directed the “The Irishman.” It tells a story that extends over 30 years. One of the stars, Robert De Niro, is 76 years old in real life. But on camera, he and his co-stars play characters from their 30s into old age. It is something that made the film one of 2019’s most celebrated movies. In the film industry, making actors look younger on camera is called “de-aging.” A number of movies released last year have used new digital de-aging techniques to make stars look young.