There were many concerns about the new "Teenage Mutant Ninja Turtles" movie, but director Jonathan Liebesman assures the film will hit all the things that made people fans of the franchise in the first place.

"When [producer] Michael Bay spoke with me the very first time, he said the charm of the Turtles is the most important thing," Liebesman says. "I think the most important thing for us, for the movie, is that we captured the fun and the charm of the Turtles I fell in love with when I was a kid watching the cartoons."

So that means that all those things you've grown to love about the Turtles are here in the film, out Friday.

"There was pizza, cowabunga, that they were mutants -- things that fans, I think, agree with that are important for the Ninja Turtles," Liebesman says.

The 30-year franchise -- which began as an independently published black-and-white comic book in 1984 from creators Kevin Eastman and Peter Laird -- is in the hands of the 37-year-old South African director who was a fan when he was a kid.

But these Turtles are light-years away from the animated cartoon from 1987. Technology has come a long way, and the new film was made using actors in motion-capture suits with the CGI added afterward, similar to the recent "Planet of the Apes" movies.

While it might seem difficult to create a film with stand-ins for your lead actors, it quickly became second nature for Liebesman.

"By the time we were on set with the actors in the mo-cap suit, it was very easy for us," he says. "It was almost foolproof to the point where I could direct the movie as if I were directing a normal drama or comedy or something because these guys had done such amazing work to make this technology user friendly."

While the Turtles were computer generated, Megan Fox, who stars as reporter and Turtles' confidant April O'Neil, is very real.

"April O'Neal is such a great character," Liebesman, who went to NYU's Tisch School of the Arts, says. "And I think that the producers' decision to bring Megan Fox into the movie is actually pretty brilliant because she, when you meet her, what you don't know about her is that she's very driven to sort of change people's perception of her and that's very much like April O'Neal."

Of course, having a star of Fox's caliber on set in New York City -- 90% of the movie was filmed here -- can lead to some unique problems.

"I had never been on a set where there were paparazzi shooting your actors all the time," Liebesman explains. "What was interesting is that there's a disadvantage in that you have to clear the guys between takes, but it was very exciting to be in a place that people were so passionate about the movie."

'TMNT' documentary teaches all things 'Turtle'

Even if you spent your childhood watching “Teenage Mutant Ninja Turtles,” you might not be aware of the colorful history of the pop-culture phenomenon. Randall Lobb’s new documentary, “Turtle Power: The Definitive History of the Teenage Mutant Ninja Turtles,” will remedy that. With the new movie coming out Friday and as the franchise hits its 30th anniversary, get to know your four favorite reptiles a lot better. (Available Aug. 12 on DVD, Video on Demand and Digital HD, $21)