Last month, we took a look at 3D movies, and I explained a little bit about how they’re made and why they seem to be everywhere now. The next big question, though, is how do we take all these great 3D movies out of the cinema and watch them at home?

Well, there are a couple ways this can be done. As I mentioned in the previous article, there were a number of television shows that used 3D as a gag or a ratings grab in the ’90s. They used the ever-popular cyan and red glasses to differentiate between what your left eye and right eye should see. You don’t need a new TV, but as we all know, once the novelty wears off, you’re left with a sub-par viewing experience.

You could use the technique that is currently the one being used in theaters: polarization. No more colored lenses, and if the show you’re watching switches from 3D to 2D, you don’t have to take off the glasses, however, moving your head can throw off horizontal/vertical polarization, and tilting your head can throw off clockwise/counterclockwise polarization. Not to mention, current TVs aren’t set up to show polarized images.

So, if you’re going to have to buy a new TV anyway, is there a better technology out there to get us our new 3D fix?

The two types of glasses discussed above are passive devices. They just sit there and let the screen or projector do all the work. The first 3D TVs that are going to hit the consumer market are going to use an active system. You’re still stuck with glasses, but instead of the lenses sorting out which image is supposed to go to which eye, they actively close off one eye while the TV broadcasts the image for the other eye.

Like LCD TVs, these glasses are filed with a liquid crystal in each lens. When a current passes through them, they darken, blocking off light. A wireless signal is transmitted from the TV, letting the glasses know which eye to darken and when so your glasses and TV don’t get out of sync.

Flicker can be a problem, except with very high refresh rates, as the glasses will switch every frame, effectively letting each eye see only half of them, but with modern high refresh rates, that’s not a very big problem.

TVs that are 3D-ready are currently available, though I don’t expect them to become as popular as HDTV has become for another 3 to 5 years. When they do become the “it” thing, HDTV prices should drop, so if you’ve been putting off getting one, your wait is almost over.

There are a few channels that are already, or will be soon, broadcasting in 3D. Channels in Japan and Korea have already started broadcasting some sporting events in 3D, and British Sky Broadcasting will begin a channel, Sky 3D, in April. ESPN will start a 3D channel on June 11, showing up to 85 live sporting events in 3D every year. A full 24-hour 3D channel is even in the works as a joint venture between the Discovery Channel, IMAX and Sony.

As with all technology, though, the replacement for these new 3D-ready TVs is already in sight. 3D TVs that don’t require glasses are already being developed. The philosophy behind these new marvels of modern science is familiar to all of us. If you’ve ever seen a “hologram” picture with ridges on it that show you a different image when you move your head, then you know what’s coming.

Lenticular screens, combined with projectors can transmit a picture that changes as you move and that gives each eye a slightly different view. These work by the same principle as that hologram image: the ridges reflect light at different angles, so depending on where you’re standing you’re seeing a different image. Very similarly, if you have multiple projectors set up, each one can show a slightly different angle of the same scene, but you’ll only see one image with each eye, giving the illusion of depth, and as you move, the images seen by each eye will change, making it appear that you’re seeing around the images on the screen.

As you can imagine, this is a very expensive set-up, requiring very precise placement of a handful of different projectors, but as with all technology, smaller and cheaper is only a matter of time.