Horror film genre's defining moment

Forty years ago this month, The Texas Chain Saw Massacre was released in cinemas. Yet even as it enters its fifth decade, Tobe Hooper's horror film remains a master class in terror, having lost little of its power to shock, fascinate and repulse - often at the same time - since it appeared in 1974.

Enthusiastically introducing a screening of a restored version of the movie at the Cannes Film Festival this year, Denmark-born Nicolas Winding Refn ( Drive; Only God Forgives) said seeing The Texas Chain Saw Massacre at the age of 14 made him want to be a director.

While not everyone's life is changed by watching the film, few forget its disturbing imagery or the creeping sense of dread it produces.

"Most horror movies, you walk out and you don't take anything home with you," says Gunnar Hansen, who plays Leatherface, the masked, chain saw-wielding killer. "This has the opposite effect. You walk out carrying a lot of baggage that it piled on top of you."

Yet despite the promise of grisly carnage in its title (others considered included Headcheese and Scum of the Earth), there is hardly any blood in the cult movie. Even so, people often swear it is the most gruesome film they have ever seen.