See Christopher Reeve’s Face CGI’ed Into MAN OF STEEL Scene
When you’re making a Superman movie, you always have the Christopher Reeve monkey on your back. For many, he still is Superman.
So the Man of Steel filmmakers gave Reeve a subtle nod in the scene where Henry Cavill’s Superman powers through stronger gravity than is usual on earth to take on Zod’s world builder weapon. You can see Reeve in the GIF above as Cavill turns his head up to the sky. Now, let’s see if someone finds a nod to Kirk Alyn.
Source: Reddit