Jon Favreau has been talking about 3D for a while now. Last year, he admitted that he would love to shoot Iron Man 2 in 3D. The problem with going 3D at this point, Favreau says, is technology. His cinematographer (Matthew Libatique) likes to shoot film, and likes the look of film. 3D would require him to shoot digital, and between that constraint and the additional expense, it wasn’t an option for Iron Man 2.

But now, AinItCool is reporting that Marvel is tinkering with converting Iron Man 2 to Digital 3D. Apparently the comic book and film company had one minute of the sequel converted into 3D as a demo, which has all the suits impressed. So impressed that they put out bid requests to three companies to see exactly how much the conversion process would cost, and how long it might take.

I’m not a 3D evangelist, but I am one of the few bloggers who believes the technology offers more than a gimmick. I’ll admit, 3D movies still excite me, especially when the technology is used to help tell the story, adding another dimension of emotional investment depth. I’m even excited about the possibility of remastering old films, like Toy Story and Toy Story 2 for example, in 3D.

I would love Love LOVE to see Iron Man flying in Digital 3D…

That said, I don’t think this is a good idea. Why? Find out after the jump.

The few live action 3D films have mostly been shot using 3D cameras, which essentially feature two lenses, one for each eye. Many of the films you see in 3D today were animated using a computer, created in a 3D digital environment, and rendered twice. If Disney wants to convert Toy Story into 3D, they return to the original animation files and render the movie with a second eye camera (there is more to it, but I’m trying to keep this simple). But with a live action film, there is no way to return to the original digital files, because there are none.

The 3D effect is created using a couple different methods, but basically they must recreate a 3D environment and graph the original image on to the 3d polygon. For a film like Nightmare Before Christmas, a stop-motion animated film, the process is passable. For sequences with humans, its less effective. Anyone who saw Superman Returns in IMAX with the few 3D sequences know what I’m talking about. You kind of get this 3D cut out effect, with layers of depth but the objects look flat. I’ve heard it has gotten better, but have not seen the 3D upconversion of the last Harry Potter film. You can see a video about how this process is done below.

I don’t yet believe that 3D created as a post process is ready for prime-time, and neither does George Lucas. There is a reason why you haven’t seen the original Star Wars films rereleased in 3D yet, even though he announced the possibility in 2005. Producer Rick McCallum confirmed a couple years later that Lucasfilm is “planning to take all six films and turn them into 3-D,” but they are “waiting for the companies out there that are developing this technology to bring it down to a cost level that makes it worthwhile for everybody.” The fact that only the first 15 minutes of the latest Harry Potter could be converted shows you the time and expense involved. Also, it just doesn’t look great. I’m not saying that it won’t eventually. But right now, its not ready for primetime. And if it was, you’d be seeing a lot more full feature films considering 3D up-conversion.

Harry at AICN mentions that Tim Burton’s Alice in Wonderland is being converted the 3D after the fact, and that is true. Tim Burton decided to shoot the live action using a 2D camera. But what you must remember is that most of that world is going to be created in the computer. Even most of the characters are performance captured. And most everyone that knows anything about the 3D process, thought Burton made the wrong decision to film the live-action segments using 2D cameras. It just doesn’t make sense.

And remember, Jon Favreau loves to blend computer animated effects with practical. So even sequences where Iron Man appears may include live action and computer created elements. So the process of turning Iron Man into 3D would be mostly a post process, like Harry Potter.