Leveraged Intelligence

3D Movies – Cool!!

Yesterday afternoon, Carol and I went to see the 3D movie Avatar.  Conrad’s review: Wow, that was cool!!!  Carol’s review: Yeah, it wasn’t too bad, but it drug in the middle.  Conrad’s response: What??

The deal for me is multi-fold.  First, it is an action movie to a large extent and that kind of makes it a guy movie to begin with.  Second, it is a genre that I like and Carol just can’t stand science fiction of any kind or fantasy that isn’t maybe Alice in Wonderland or something.  Third … to do this requires some cool gadgets!!!  I’m in Heaven.

Note at this point: if in a 3-hour movie Carol didn’t go to sleep or walk out, you know the story was actually pretty good.  For $400 million, it damn well should be – and I heard this morning that it has sold over $1 billion so far.  It takes a James Cameron for a studio to risk this much.

But, anyway, back to the gadgets, back to the magic.  How the heck do they do it?  And, is it really that much better than the old 3D with glasses that were red and blue plastic?  The answer to the second question is that it is in a totally different league than the old 3D movies where they tried to scare you by having a pole stick out or a monster come out after you.  Then, you would take the glasses back off and they would tell you the next time to put them on.

Now, the entire movie is 3D.  And, the 3D image is extremely realistic.  For one thing, there isn’t any of that color bleed like the old ones had, the colors are the normal colors start to finish.  And … this is how they do it.:

There is a spinning disk spinning at 3 revolutions for each frame of film.  It has to go fast so you don’t see a flicker – and so that it doesn’t induce an epileptic seizure in susceptible people.  Seriously!  When I became a science teacher, one of the items we were sent was the frequency at which to never set a strobe light.  There is some kind of a resonance that can induce seizures and the spinning disk has to be sure to not hit it – like that Japanese movie a few years ago that nailed a bunch of folks!

Half of this disk is polarized vertically and half of it is polarized horizontally.  By polarization, it means the plane in which a wave oscillates.  In plainer plane language, if it is polarized vertically, that means the waves only go up and down.  If polarized horizontally, they only move side to side.

You have had sunglasses the had polarization filters in them, because reflected light tends to bounce in one plane predominantly, the horizontal plane.  So, they have vertical striping that only allows vertical waves to pass through, just like you can only go through a door standing up and not laying sideways on a cart.  They hand our polarized lens glasses to you when you enter the theater, but they are not dark glasses and each lens is polarized in the opposite orientation.  So, the left eye, for example can only see vertical waves and the right can only see horizontal waves – or vice versa.

Now, there is a hole in my knowledge right here.  I don’t know why this disk spinning three times per frame would divide images appropriately – I think it has to do with Red, Green, Blue presentation – but there are alternating images that are cast on the screen, one that can only be seen with the left eye and one that can only be seen by the right eye.

This is happening so quickly that the brain thinks each eye is seeing one image continuously.  Well what is the brain doing with these two images that is so special?  The same thing it does every day.  Your right eye is never seeing exactly the same thing as your left eye.  The closer something is to you, the more the difference in what the two eyes see.  Want an example?  Look down and tell me how many noses you see.  Didn’t know you had two of them, did you?

When something is far enough away, then the two eyes distinguish no difference whatsoever.  Neither eye can tell any difference when it looks at a star as compared to the other eye.  So, giving the illusion of depth is conceptually fairly simple.  If the object you are showing is supposed to be close, give the two images a fair amount of separation, each image looking at the object from a slightly different angle.  If the object is supposed to be far away, present the two images pretty much together.

Voila!  3D.  Cool!!

Tags: 3D Movies, Avatar