Many big names were attached to the part of "Superman". How come you, an unknown, were cast?
When first trying to cast "Superman", the producers started with very big names at the time from Robert Redford to Sylvester Stallone. They then realised that it would be better to cast an unknown in the part and surround him with a lot of famous actors. My picture had been shown to director Dick Donner and producer Ilya Salkind three or four times, and every time they said no. They felt that I looked too skinny and didn't have the right look for the part. Finally in January 1977, casting director Lynn Stalmaster presented my picture again and they finally agreed to meet me briefly in New York. The next day I was asked to go to Shepperton Studios outside London for a screen test, where I did two scenes from "Superman II". I was told that I had the part even before I got on the plane to fly home.
With production scheduled to begin in March 1977, were you aware of the pressure to cast the main part?
I didn't know they were under such a deadline. That would have made it difficult for them in negotiating with my agent, so they created the impression that I was just one of many possible candidates. But they were getting quite desperate because they'd interviewed a lot of people, and had got to the point in December 1976 where the producer's wife was sitting in the dentist's chair, looking up at her dentist and she suddenly thought, "He looks like Superman". They gave him a screen test - those were the lengths that they were going to.
Being very much an unknown back then, were you eager to get the role?
By that time in 1977 I had tried out for many parts and I was used to screen tests and auditions, so it was not particularly intimidating. Also, I have to admit that I had not really invested much in playing Superman. I thought that it was a long shot. I enjoyed the trip to England but it didn't really matter to me whether I was cast or not. Often when you're not overly keen about being cast, you relax, then you end up being cast.
How did the quality of the effects influence your performance as "Superman"?
I realised that because the special effects were so good I was able to underplay the character. In the past they never had such convincing special effects, so a lot of Superman's mystique was created by poses. In contrast, I was able to be casual, and a good example of that is the balcony scene with Lois, where I talk about my background and I offer to take her flying. It's all done with the mood of two people getting to know each other on a first date. I was really glad that I could play the part in a naturalistic way, and that was only possible because the special effects were state of the art for their time.
"Superman: The Movie" is now available to buy on DVD