It has been nearly forty years since Superman: The Movie was in theaters, and yet a scene from that film has been making the rounds on the internet for several days, causing fans and critics to remark on just how special star Christopher Reeve's performance in the film really was.
The scene, which takes place just before Lois Lane's date with Clark Kent, clealry demonstrates the way Reeve differentiated his performances for Superman and Clark.
When Clark prepares to admit to Lois that he is also Superman, he not only removes his glasses but straightens up his posture and changes his voice and expression. When he decides against revealing himself, he reverses those actions, leaving himself a shriveled and uncertain Clark again.
When he reinvented Superman in the 1980s in the miniseries The Man of Steel, writer/artist John Byrne utilized this trope, explaining in The Man of Steel #1 that it was much more than just the glasses that would change.
“With his hair slicked back and an old pair of my spectacles, his whole face seems to change,” Jonathan Kent says in that issue. “All he needs do is stoop a tad, and he looks like a whole different man.”
Clark also reasons that if Superman appears unmasked, most people will have no real reason to believe he even has a dual identity at all.
In the years since Reeve, there have been numberous actors who played Superman, but none has captured the imagination of the audience the way he did -- and this is a good microcosm of why.