“So from there on I made all their science fiction films, and the more I did of these films the more I liked it because the studio left me alone. No one at that time was an expert at making sf films so I claimed to be one. I wasn't, of course, but the studio didn't know that so they never argued with me, no matter what I did. In most of my sf films I tried to create an atmosphere because I think if you shoot an imaginative film--a film in which you ask an audience to believe things that are bizarre--you have to make them believe it. You can't do this with the story or actors alone, you have to create a kind of atmosphere while shooting it in which the audience's credibility will be suspended to the point where they don't say to themselves: "That's impossible!"”

Jack Arnold in The Horror People http://eric.b.olsen.tripod.com/arnold.html (1976)