Last night I saw Titanic 3D at the IMAX and -- surprisingly -- the 3D is actually pretty good.
Why is that surprising? Because Titanic wasn't filmed using 3D cameras. Back in 1997 we were perfectly content to watch Leo and Kate legging it around the sinking ship in the usual two dimensions.
Filming a 3D movie using proper 3D cameras means that the depth of the extra dimension in every scene is exactly as it should be. If you embark upon a 2D-to-3D conversion, however, you'll need to use software that makes a guess at exactly how deep each object on screen should appear to be.
It often ends badly, with on-screen characters coming out of the post-conversion process looking lumpen and horrifying, while action scenes prove impossible to follow because your eyes can't make sense of what's behind what.
But Titanic 3D did an excellent job of proving the conversion tech isn't a complete write-off. Depth effects were subtle, accurate and -- most importantly -- not distracting. The film itself didn't look too dark, and the action scenes were impressive, with no gimmicky poking-out-of-the-screen bits.
Of particular note were the scenes of the underwater wreck, which is pushed subtly to the background, while the bubbles and tiny bits of detritus in the water are brought to the foreground. It gave a great sense of moving through the water, even if it was highly reminiscent of this classic screensaver.
There were a couple of moments in the three-and-a-half-hour long epic where some on-screen objects looked slightly out of whack with their surroundings, but for the most part I was able to forget about the 3D completely, and focus on wondering how Jack and Rose have ended up below decks again.
The conversion reportedly took 60 weeks, costing $18m (about £11m), perhaps signalling that the best way to convert a 2D movie to three dimensions is to spend a truckload of money on it.
I'm still sceptical when it comes to 3D. But if you're looking for an example of the technique handled well (and don't mind enduring over three hours of emotional exhaustion), Titanic 3D is worth a look.
Have you seen a shockingly poor 3D conversion? Or an example of 3D tech used correctly? Tell me in the comments or on our Facebook wall.