CANNES, France – Fear and trembling attend the release of “Star Wars Episode III: Revenge of the Sith,” which screened yesterday at Cannes and opens Thursday in New York. The fear is more than justified: Impersonal and inept, Episodes I and II travestied the beloved “Star Wars” mythos and must rank amongst the most insipidly overwrought and undernourished spectaculars of the digital era.

But it isn’t just those who spent the last week camped out in front of the Ziegfeld in Boba Fett pajamas that feel a twinge of excitement over the release of “Sith,” the final chapter in the most influential movie franchise of all time. The very title is exciting. If “Attack of the Clones” sounded like the name of a chintzy kindergarten sci-fi – and lived up to it – “Revenge of the Sith” suggests conspiratorial malevolence, nasty business. Something for the older kids.

Then again, George Lucas could have called his movie “Food Fight of the Squiggly Wigglies,” and Star Wars babies from here to Tatooine would still shiver in anticipation. For those of us who grew up with Luke, Leia, Han, and Yoda, who dreamt of piloting X-Wing fighters and wielding our very own light sabers, the “Star Wars” narrative is hardwired into our imaginations, just as Westerns were for a previous generation.

Mr. Lucas could not possibly have lived up to such an enormous (and irrationally exuberant) legacy. But what so deeply disappointed the cult was the extent to which he failed to replicate even the smallest charm of the original trilogy. For all their shortcomings, the first three movies were playful, enthusiastic entertainments, attentive to human quirks and foibles. The prequels are a triumph of machine over man. They might have been directed by the Death Star itself, were they not so shoddily constructed. I was shocked by the failure of “Attack of the Clones” to make use of even the simplest of reaction shots.

However else that film goes down in history, it will stand as a landmark example of the perils of total digitalization. No wonder the actors looked confused: Directed to perform in a vacuum later filled in by computer effects, they were literally cut and pasted into their scenes. And for all the time and money lavished on their artificial universe, Mr. Lucas and his army of technicians hadn’t mastered their tools. Areas of the image, especially in the blacks, blotched and hiccuped with instability, making the entire picture seem even more insubstantial than it already was.

The first good news to report of “Sith” is that the technology has greatly improved; “Star Wars” is back in black. See the movie nowhere but at the Ziegfeld; the next-level digital projection is simply flabbergasting. Even in purely technological terms, however, the movie is a Pyrrhic victory. The clarity is hypnotic, the movement of forms faultlessly smooth, and the humans more credibly merged with their CGI environment. Dazzling – and dull.

The opening is a monotonous tour de force. Supreme Chancellor Palpatine (Ian McDiarmid) has been kidnapped by General Grievous (CGI-voiced by Matthew Wood), robot leader of the Clone army. Jedi hero Anakin Skywalker (Hayden Christensen) and his mentor Obi-Wan Kenobi (Ewan McGregor) attempt a rescue in the middle of a gigantic interplanetary battle. Make that the gigantic interplanetary battle.

In an extended single “shot,” the image zooms from micro to macro perspectives as the Jedi spaceships corkscrew through a swarm of laser beams and enemy craft. Hundreds of actions, big and small, vie for attention in the monumentally complex tableaux. There’s so much visual information to process that the mind registers awe after the fact. “Sith,” overstuffed with these over-processed set pieces, can feel like an intergalactic Jackson Pollock painting come to life, or some terrifyingly complicated “Where’s Waldo?” animation.

Things clear up once Anakin and Obi-Wan penetrate Grievous’s warship. Out come the light sabers for a scuffle with Count Dooku (Christopher Lee), and out they remain for most of the next two-and-a-half action-packed hours. Mr. Lucas’s filmmaking chops have taken a step forward, but he’s still behind the curve. Now that Western audiences are accustomed to the virtuosity of wuxia swordplay, the endless duels of “Sith” feel a little shopworn. Mr. Lucas should have unplugged some of the effects and placed an order for the wire-work of Yuen Wo Ping.

Once Palpatine is sprung, Anakin heads home to his beloved Padme (Natalie Portman). She has become pregnant with you know who, and Anakin is tormented by prophecies of her death in childbirth. There may be a way to save her, however – a Dark way! Adding to his angst, the petulant hothead is finally initiated into the powerful Jedi Council but denied the title of Master. Obi-Wan insists on patience and restraint; Anakin’s getting fed up. Kid’s got a chip on his shoulder the size of the Millennium Falcon.

Palpatine will turn that chip into a suit of black techno armor: “Sith” is the story of Anakin’s seduction to the Dark Side of the Force and his metamorphosis into Darth Vader. This will involve secrets, conspiracies, and betrayals to be discovered on your own. Happily, you should find these far more involving than anything in the previous films, even if the expository dialogue still plays as if for the benefit of dyslexic five-year-olds.

Anakin’s moral quandary is intelligible, a rare quality in these prequels. Once his switch is thrown to the dark side, he prostrates himself a bit too quickly (and far too literally) at the feet of the evil, yet the forces that compel him are dramatically convincing. Mr. Christensen, alas, is not; he makes Mark Hamill look like Marlon Brando. The George Hamilton tan that smothered him in “Clones” is gone, but the lack of affect remains.

I’m no longer sure that all the blame for the atrocious performances in the previous films lies in Mr. Lucas’s indifference to actors. He fails to quell Mr. McGregor, who steps into Alec Guinness’s shoes with his wonderful performance of Obi-Wan. Mr. McDiarmid is deliciously hammy; had he a moustache, he’d twist it maniacally. But Darth Vader should be a role of Shakespearean grandeur, and Mr. Christensen is a pip-squeak.

“Revenge of the Sith” improves on its predecessors in every department, but it’s still depressing that a filmmaker with the whole world literally at his fingertips prefers to muck around in his hard drive. Production took place in China, Italy, Switzerland, Thailand, and Tunisia, but any trace of these locations that made it into the image is coated with so much digital paint as to appear utterly synthetic – a vast panorama of streaming iPlace.

Dagobah, Cloud City, Tatooine, the Ewok Forest, the ice planet of Hoth: those were settings with real personality, palpable atmospheres, and – imagine! – narrative function. Meticulously designed as they are, settings in “Sith” have a weightless, perfunctory quality to them, and they’re all wildly over the top. The megapolis of the Republic, an outlandish ant farm of flying cars that stretches for light years in every direction, is so gigantic it would give Andreas Gursky a headache.

The Wookie planet is a wan, waterfront mirage studded with Swiss Family Robinson tree forts on crack. I expect the toy will be excellent, but the movie version has all the presence of a kitsch afterthought. A crater community carved in a spiraling Guggenheim ramp looks fascinating, even inviting, but the structure is obscured by a haze of CGI. The climactic confrontation between Anakin and Obi-Wan on the banks of a volcanic inferno is impressive until they start surfing over it like some outtake from ‘Spy Kids 3-D.”

“Sith” may be slight, but it casts a strange spell. Gazing into its unprecedented digital light for so long induced a low-grade kind of hypnosis in this viewer. As I turned the movie over in my head, I tried to imagine how it would play to the uninitiated. It wasn’t easy to do, and not only because I’d developed a crushing migraine. My brain couldn’t imagine a world without “Star Wars.”

Ignorance may be impossible, but for maximum enjoyment of “Sith,” indifference to the “Star Wars” legacy is recommended. Remember the words of Yoda: “Fear leads to anger, anger leads to hate, hate leads to suffering.” Train yourself to let go of everything you fear to lose.