Nearly every major Theater has an Imax auditorium now, but what is it exactly? Is it just a bigger screen? Bigger sound? Well, the answer isn't as clear-cut as you might think.

IMAX isn't a Film format like what Academy 35mm film is. It's an entertainment technology company based in Canada. They're the ones who decide what to brand as "IMAX."

Traditional IMAX is a special way of shooting 70mm film. On a regular camera and projector, the film is fed through vertically. On an IMAX camera, the film is fed through horizontally, allowing for twice as much area to be exposed per frame. This creates an image that is much clearer and more detailed at the expense of using up more film.

The downside is real IMAX films are logistically and financially ungainly. Traditionally films are limited to just 40 minutes, but 2-hour run times are possible with massive 2-meter wide film platters that are so heavy they have to be moved with a small crane. This posed a rather serious money-making problem for theaters and the IMAX company itself since nice, juicy Hollywood films were excluded.

Their solution was to broaden the definition of IMAX. One solution is to shoot certain scenes of a movie in IMAX, but switch to regular film when you have talking heads. They did this with The Dark Night. Action sequences were in IMAX, but the rest of the film was projected digitally in 2K video (which is slightly higher res than 1080p.)

The second solution (and sadly, the most common,) is to project blown-up 35mm film or 2K video and call it IMAX. Which is no more detailed than a cheaper presentation in a regular theater. This is called IMAX DMR (Digital Media Remastering) and is a huge ripoff. Though I see it as a temporary setback until 8K and 16K (IMAX-equivalent resolution) video become more feasible in the next ten years. You see, at the moment there is no editing system on the planet that can handle 16K video, nor do any projectors actually exist that can display it. So for the time being, physical film is vastly superior.

IMAX cameras tend to be very large and heavy, which makes filming with them very challenging. The Discovery Channel reality show, Storm Chasers, recently featured IMAX filmmaker Sean C. Casey and his armor-plated camera truck, TIV2, as he travels the American Midwest in search of his perfect shot of the inside of a tornado.

The TIV2: A Glorified Camera Mount designed to intercept an F3 tornado.

The Camera itself. 92 pounds and well over $100,000.

Casey's camera is about as portable as they get. Running through all of its film in 3 minutes. Buying the film and developing costs about $2,400 for that one 3-minute roll. So you can understand his frustration when he doesn't get his shot.

IMAX 3D is still a confusing title, because it still doesn't tell you what you'll be seeing. Most of the time (like with Avatar) you're just seeing a standard-def format blown up to fit an IMAX screen. Laaaaaaame. However there are real IMAX cameras that can shoot 3D... and they are truly massive.

Warners Bros. and NASA have teamed up to produce a spectacular-looking film that will be shot in "real" IMAX 3D. NASA custom-built a 700-pound (300Kg) camera that would satisfy weight-restrictions and be able to withstand the harsh environment of space. Unlike a regular IMAX 3D camera, this one shoots on only one reel of film. Alternating left and right eye perspectives per 2 frames. The film is then transferred to two separate patters (one for each eye) and projected at the same time through polarized filters to create the illusion of 3D. If you're not excited to see this movie, you are clearly dead.

The lesson you should take away from this article is to be wary when a film is advertised as IMAX. Especially if it is a feature film. Even The Dark Knight, which had brilliant scenes shot in real IMAX... only totaled up to about 8 minutes out of the whole film. Do a small bit of research to make sure that $3 premium is actually worth it. Because usually it isn't.