A timely and entertaining window on the side effects—and even some of the causes—of celebrity culture, Teenage Paparazzo definitely knows what it’s talking about. Writer-director Adrian Grenier was particularly well placed to open such a porthole.

“I’m not really a celebrity, but I play one on TV,” he says early in the documentary, referring to his role as a rising Hollywood star in the cable series Entourage. The new film, which opens Friday (August 27), isn’t his first directing job. Eight years ago, Grenier made the very personal Shot in the Dark, about the search for his birth father. He’s since directed the darkly comic short “Euthanasia” and helped produce a feature doc about struggling musicians called Don’t Quit Your Daydream.

“I’ve always made movies,” says Grenier, calling from his cellphone somewhere in the Los Angeles foothills. “When I was in high school, I used to make these gross, immature Hi8 films with my friends. We actually put them on public-access TV—our version of YouTube, I guess. Some of those things were totally inappropriate.”

That rude pioneer attitude is one quality that attracted the 34-year-old actor to his film’s young subject, Austin Visschedyk, a fair-haired Angeleno teenager who grabs fresh images of Paris and Lindsay et al and fires them off, usually in the middle of the night, to waiting tabloid editors in London and New York.

“I found Austin to be such an autonomous, independent spirit.” Grenier says. “His awareness of the media is so impressive. At first glance, you may be repelled by his choices of how to use it, but if you peel back the layers, you realize that there is something rather inspiring about what he does. The fact that he has the savvy at 13 to command all that communication is pretty remarkable. I think you have to recognize the creativity of kids and not just squash it right away.”

Shot over three years, between episodes of Entourage, Paparazzo is not just a celebration of youthful antics, however. It’s a critical look at gradual shifts in an adolescent’s basic personality (as glimpsed at the kid’s slightly dated Web site).

“All this reality TV is a bunch of hogwash,” the filmmaker asserts. “They’re forcing change in a short period of time, and you have to allow that to happen naturally. That’s why I much prefer the more meditative, vérité style of documentary.”

As his story moves along, Grenier gets more serious in his inquiries regarding the electronic culture that children, and almost all consumers, now find themselves inhabiting.

“That was the movie’s Trojan horse. This whole thing actually started when I read a book called Mediated: How the Media Shapes Your World and the Way You Live in It, by Thomas de Zengotita. And when the project got under way, I found Tom and got him more involved with it.”

Other voices, from Hollywood insiders to academic theorists, were filmed. But some clips, the director admits, will only be seen on the DVD version.

“I really wanted to be able to say, ”˜I made a movie with both Paris Hilton and Noam Chomsky.’ But, sadly, Noam didn’t make the cut!”