London, June 10: It’s an eagerly-awaited prequel. It has at its heart a troubled young man wrestling with his dark side, who ends up prowling around menacingly in a long black cloak. And it’s not Star Wars Episode III.

As Batman Begins joins battle with Revenge of the Sith at the box office, the similarities are uncanny, but the differences put them light years apart. The sixth episode of George Lucas’s space opera is a flashy, overwrought mess, whereas Christopher Nolan’s vision of the Caped Crusader’s early years is a thrillingly noir-ish treat. And, in many ways, it’s all down to technique.

For a director working in the fantasy genre, it was a brave decision by Nolan largely to eschew that increasingly de rigueur ingredient of mega-bucks productions ? computer-generated imagery. He says for a film of its size, Batman Begins probably holds the record for fewest CG shots, and he resisted suggestions that the Batmobile should be digital, building instead a “real” one weighing two-and-a-half tonnes.

Sith, on the other hand, is challenging for the record at the other extreme by featuring more than 2,000 optical effects. That’s about one every four seconds and more than four times the number used in another imminent box-office behemoth, War of the Worlds, directed by Steven Spielberg, himself no slouch when it comes to visual trickery.

The scrolling introduction to Sith proclaims: “Evil is everywhere”. It is, and it’s called CGI. Despite the technological advances, today’s blockbuster simply doesn’t look as good as it did when Lucas and a handful of others invented the phenomenon in the 1970s. Back then, special effects helped to move the story along; nowadays they are increasingly in danger of overwhelming it.

This isn’t a neo-Luddite call for a return to the old days of SFX, although Hitchcock’s screechingly malevolent Birds were genuinely horrifying.

There is a place for CGI. Indeed, it works best where it’s used exclusively, as in those triumphs of animation Shrek 2 and The Incredibles, both of them clever, witty and utterly delightful.