Roger Corman is shown on the set of 1970’s “Bloody Mama,” just one of four movies the producer released that year.

Everything you need to know about B-movie king Roger Corman is contained in one scene of the new documentary “Corman’s World: Exploits of a Hollywood Rebel.” Corman is preparing to receive an honorary Oscar in 2009, and his wife is struggling to get his bow tie just right. “It’s supposed to look imperfect,” Corman says. “That’s how people know you tied it by hand.” This says a lot coming from a man who embraces monsters that clearly look like puppets.

“It was a great little nugget,” says “Corman’s World” director Alex Stapleton. “It runs completely parallel to the types of movies he makes. [We’re in] an age where movies are such a digital experience — so much CGI work that it looks so perfect and there’s so much money. Then you look at Roger Corman movies and they’re all handmade.”

“Corman’s World,” opening locally Friday, combines a history of Corman’s work with interviews about his effect on modern film. Over the past half-century, Corman has produced hundreds of low-budget, somewhat schlocky flicks that include “Wild Angels,” the original “Little Shop of Horrors” and, more recently, SyFy’s “Sharktopus” (and “Dinoshark” and “Piranhaconda”).

These “handmade” movies tend to get stuck with the misleadingly pejorative “exploitation genre” label, a shorthand way of saying there will be a lot of nudity or a lot of blood — probably both. “People underestimate how difficult it is to make genre films,” Stapleton says. “You can even argue that it’s harder [than a non-genre film]. Genre audiences are very particular. That’s Roger’s domain, and he’s perfected the science of that.”

Corman gave many big-time directors their start — including Martin Scorsese, Francis Ford Coppola and James Cameron. (Scorsese appears in the film, as does, in the film’s most stunning moment, a tearful Jack Nicholson.) While Stapleton doesn’t consider herself an alumna of the “Corman School of Film,” she has audited a few classes. Growing up in the ’80s, she watched dozens of Corman films on TV (without knowing who Corman was).

“When I was a teenager, I wanted to become a director but didn’t have the opportunity to go to film school, so I used books and [DVD] commentaries. One of the books I picked up was Roger’s autobiography. The fact that one human being was responsible for so many movies I liked and responsible for launching so many careers. … The man behind all of this was Roger Corman.”

West End Cinema, 2301 M St. NW; opens Fri., $8-$11; 202-419-3456. (Foggy Bottom)