March 25 is going to be a big day for superhero movie buffs. It’s the opening of Batman v. Superman, the first time those characters have ever appeared together in a live-action movie. (It will also be the first feature-movie appearances of Wonder Woman and Aquaman.)

It’s a big movie, opening on 30,000 screens worldwide, in every format known to box-office humanity: 2D, 3D, 4DX, and IMAX 3D.

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You can read about the tech specs of IMAX on Wikipedia, but you know the basics: Filmmakers use a huge camera containing huge spools of film (or huge hard drives for digital video) to capture video that projects onto really huge screens.

In the old days, you’d see 40-minute IMAX nature movies at science museums. These days, IMAX is a way to get people out of their home theaters and into real theaters to see big-budget blockbuster movies on enormous screens with unbelievable resolution.

To celebrate the opening of Batman v. Superman (and to scratch a few curiosity itches of my own), I recently spoke with Brian Bonnick, the chief technology officer of IMAX, to talk about the technology.



David Pogue: Is IMAX still that gigantic-format film and those gigantic cameras?

Brian Bonnick: Actually, it’s changed like you wouldn’t believe.

The film-based projectors haven’t really changed a whole lot. They got better and a little bit cheaper, but in their core design, they didn’t really change.

But we moved over to digital [in 2008], and that’s gone through multiple iterations. We’re constantly updating the computers powering the systems. They’ve become more and more powerful, which means that we can do more things with it.

Recently, we launched our laser projection system — a ground-up development of a next-generation system utilizing lasers.

Most of the other players out there use laser illumination as a way to improve brightness. That’s great. But we were trying to address three key problems that plague digital projectors: lack of brightness, lack of contrast, and lack of sharpness.

This all tied back to the prism. The light bounces into this prism and bounces off of three chips to create the red, blue, and green pixels. But now you’ve got this stray light hitting each of these chips. That degrades the image contrast quite a bit.

So we threw away the prism. We incorporated what we call a frame design. Instead of having these chips mounted to a chunk of glass, we mounted them to a frame in the right positions. By removing the glass, we got rid of any cross-reflection, so our contrast took a giant jump upwards.

And then, by going with this open frame, we use invar [a nickel-iron alloy], one of the most thermally stable materials on the planet. So while we still have expansion and contraction, all of the components expand and contract at the same rate relative to one another. Combined with changes to the optics of the system and our own custom designed lenses, we are getting unbelievably sharp images on the screen. In my opinion, it now exceeds that of what used to be the world benchmark, which was IMAX 15/70 film.

We use dual projectors. One of the artifacts that all digital projectors have is the “screen-door effect,” which is where you see the little black lines between the pixels. The dual-projector system immediately cuts that down 50%.

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DP: Two projectors: Is that for 3D only, or all IMAX?

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