Now is not the time to debate whether 3-D is a good or a bad thing. Frankly, that ship has sailed. It must go without saying that the format is cumbersome, imperfect (am I the only person who sees a slight shadow or discord on some of the 3-D images?) and an all-round impediment to the immersive properties of cinema.
Movies shot in 3-D tend to favour visual wizardry at the expense of other aspects of film-making – imagine how good Avatar would have been, for instance, if the characters and emotions had felt as real as the shrubbery. Those pictures that undergo the conversion process in post-production (Alice in Wonderland, The Last Airbender) invariably have all the optical depth of ashtrays.
But it's about to get much worse: 3-D is as transparent a way to squeeze more money out of audiences as forcing them to buy their popcorn in gold-plated buckets. That much we know. (And if you object to paying a surcharge for 3-D glasses on top of the extra cost for a 3-D film, it's no good bringing your own – the unlovable Vue cinema chain, at least, charges you for specs whether you need them or not.)
Now the industry has hit on a way to not only make us stump up an extra couple of pounds for a 3-D film, but to get us to pay all over again for films we've already seen. Directors including James Cameron, Peter Jackson and George Lucas are busily feeding their past blockbusters into the 3-D Movie Maker. I see it as a kind of mincing machine, like the one into which the teacher stuffs children in the video for Pink Floyd's "Another Brick in the Wall Part 2", only in this one you cram film stock into one end, and billions of dollars emerge from the other.
This is some kind of evil genius at work. You might compare the drive to get us to pay repeatedly for the same product to the rise of the CD or DVD industries, except that at least in those cases there was a noticeable change in quality, even if vinyl or VHS junkies would argue that this change represented nothing so much as a homogenisation.
The prospect of watching the Lord of the Rings trilogy or Titanic in 3-D causes not joy in my soul, but a severe pre-emptive ache on the bridge of my nose from the weight of all those unwieldy pairs of glasses.
It is only on hearing the recent news that Lucas is converting his Star Wars series to 3-D, for a one-episode-per-year rerelease campaign beginning in 2012, that you learn precisely how low your heart can sink.
"Lucasfilm Ltd has announced that the live-action Star Wars Saga will be converted to 3-D!" trumpeted a 20th Century Fox press release two weeks ago. You would think the news couldn't be any more depressing, and then you notice the exclamation mark at the end of the sentence. Is it meant to convey a jaunty, excitable sense of anticipation? Or an incredulous sentiment along the lines of: "Can-you-even-believe-what-they'll-do-to-fleece-you-suckers?" Take your pick.
"Getting good results on a stereo conversion is a matter of taking the time and getting it right," says John Knoll, visual effects supervisor for Industrial Light & Magic. "It takes a critical and artistic eye along with an incredible attention to detail to be successful. It is not something that you can rush if you want to expect good results.
"For Star Wars we will take our time, applying everything we know both aesthetically and technically to bring audiences a fantastic new Star Wars experience." Early reports, however, suggest that the series will still be shit.
Exempt from this, naturally, is the second Star Wars film, The Empire Strikes Back (yes, I know it's fifth in chronological terms), a wonderfully alive and searching picture which is all the more remarkable for being a fluke part of this moribund series. But even that won't be altered by 3-D. No film was ever improved by the process.
A good film is a good film; a bad one is beyond saving. Even those pictures that use the process judiciously, such as Up and Coraline, or the ones that mine its trashiest potential (the recent Piranha remake, which rose in my estimation once Cameron had denounced it for "cheapening" 3-D), would not have been affected one way or the other, had they been released in 2-D only.
That's why I would urge Harry Potter fans not to fret over last week's announcement that the upcoming Harry Potter and the Deathly Hallows: Part I, due to open on 19 November, will not be in 3-D as expected. "Despite everyone's best efforts, we were unable to convert the film in its entirety and meet the highest standards of quality," Warner Bros said.
Deathly Hallows: Part II, which arrives next July, is still on course for a 3-D release, so it's not all good news. But we should at least be grateful that this particular mass raid, on family budgets already threatened with depletion by the child benefit catastrophe, has been averted.
Then again, cynics would say it's merely a deferral. Next year brings the last Harry Potter film, and it can't be long before Warner Bros announces that the entire saga will be "converted to 3-D!". Flogging a dead horse somehow looks even more unsightly with that extra dimension.