The director George Romero first sent his zombies to go forth and multiply back in the Johnson administration. Besides launching an exceedingly beloved and respected horror franchise, “Night of the Living Dead” was also, it’s often forgotten, a significant feat of independent filmmaking in a decade that saw innovative portable technology spur a new wave of cinema.

Times change: Forty years later, the maestro of satirical flesh-eating has aimed his latest barbs at the unchecked cacophony of … do-it-yourself media. An already dated artifact of the age of YouTube, Mr. Romero’s new “Diary of the Dead,” which opens today, is the fifth installment in a durable series that has always freely and fruitfully intermingled blood and guts with social commentary. But in the latter regard, it’s also the most explicit, and the commentary threatens to bog down Mr. Romero’s considerable talents as both entertainer and gadfly.

This time the premise, along with the anxiety, is meta: What we are watching is an incomplete home digital video movie, “The Death of Death,” shot by a film student, Jason (Josh Close), and annotated by his girlfriend, Debra (Michelle Morgan). The footage begins on the set of a mummy thriller that Jason is shooting in the woods of rural Pennsylvania with fellow students and his drunken professor (Scott Wentworth). News reports of zombies halt the little production. (“Diary” demonstrates typical Romero resourcefulness by setting the story during the first outbreaks instead of slavishly picking up after the events of the last entry in the series, 2005’s “Land of the Dead.”) Jason, glued to his viewfinder, flees with his companions across the countryside in a Winnebago, pit-stopping at abandoned refuges: a hospital, family homes, a farm, even a survivalist bunker. Shuffling flesh-eaters are encountered and dispatched with varying success, but one of the earliest deaths presages the underlying self-accusatory theme: After running over what might have been zombies, Mary (Tatiana Maslany), the group’s soft-spoken driver, shoots herself in despair over the possible error.

This early shock is in keeping with the self-serious opinion bulletins that periodically interrupt the story — Debra’s after-the-fact addition to Jason’s original testament. These consist of news clips from the zombie disaster paired with Debra’s voice-over, musing on the insatiable attraction of recording life on video and the ethical and emotional bankruptcy that results. In the live-action segments, too, she needles Jason about the same issues whenever he turns the camera on her, though a glimpse at the Internet at one point reveals other survivors posting on the Web amid sporadic media reports.

Most of this is a drag and, well, overkill, even if Mr. Romero’s defense could be that it’s a pseudo-profound undergraduate talking. Fortunately, the filmmaker’s horror chops are as swift and sure as ever, and comedy and Grand Guignol are never far from his scenarios. For every bit of pontification, there’s a deftly cut attack in a cramped space, a fresh kill (a two-in-one skewer, acid), changeups in suspense that only a practiced hand could pull off, or, in what amounts to a directorial dare, the wholly surprising encounter with an Amish mute holdout in a stable.

But the vocal worrying about deadening voyeurism tips the balance and pins down the movie. Mr. Romero’s use of metaphor has never been entirely subtle, but his setups have been reliably malleable and reflective of an era’s concerns: racism and anarchy, consumerism, class tensions with the zombie divide and the life-and-death threat carving lines in the sand. The “cult” moniker never seemed so accurate: The durability of Mr. Romero’s zombie conceit and its pop interpretations are on par with a minor religious text.

Here the 68-year-old director sabotages himself by building in self-awareness and boldfacing the Signs of the Times, like Jason obsessing over the number of hits garnered by the videos he uploads along the way. The director would be better off with the straight-up staging of issues that a genre effort allows, like the scene involving the heavily armed and supplied bunker maintained by an all-black band of survivors. The negotiations between their leader and Debra provide a neat sketch of power dynamics and compromise.

“Diary of the Dead” winds down with a foreboding hush in a mansion, the family home of cowed brat Ridley (Philip Riccio), who skipped out on Jason’s creature feature in the beginning. Mr. Romero brings the porousness between moviemaking and reality full circle here, and Ridley’s oddball evasiveness even calls to mind the eccentric Gothic proprietor of classic horror (much as the students’ British professor sounds like the world-weary tippler no one listens to).

It’s impressive in itself that Mr. Romero still gets juice out of his series (and manages not to be upstaged by the last-testament approach of “Cloverfield”). And there’s little comparison between Mr. Romero’s expert workmanship and today’s feeble horror efforts. But the humorous image of the filmmaker glimpsed in a recent newspaper profile — ruminating over today’s “absolutely uncontrolled” information glut, from an apartment full of cat toys — keeps coming to mind. Yes, as image-cannibalizing media consumers, we are all zombies, but I’d settle for smaller helpings of purportedly up-to-the-minute critique.