Now that Avatar is officially the highest grossing movie of all time, it's inevitable that studios will continue to push 3D as the new frontier of cinema. But actually filming in 3D is prohibitively expensive. Here's how they fake it.

Not many directors share James Cameron's obsession with three dimensional authenticity, and not many films have the budgets to support the directors who do. Filming in 3D requires the use of two cameras, barely offset, capturing all the action in tandem. The technology involved, and the people who know how to use it, come with a high price tag (to the tune of seven figures). So most of the 3D movies that will be coming out of Hollywood in coming months, including the two new Harry Potter films as well as Tim Burton's Alice in Wonderland, create the effect in post-production.

Click gizmodo.com for the whole story.