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3D Glasses for HDTV: Active vs. Passive

Growing up I remember the first time I saw a commercial that channel 11 was planning on broadcasting an actual 3D movie from the 1950’s! It was House of Wax with Vincent Price. In order to view the 3D, you needed special 3D glasses that contained both red and blue lenses or a very early version of polarized glasses which we will discuss later on in this article. For the movie industry it was a very exciting time, indeed!

Fast forward to present day and it seems that almost every movie being released in the theaters are filmed in 3D! Personally, I have no problem with that, providing the story is not sacrificed due to gimmicky 3D. What I do have a problem with is the up charge of $3 to $4 for the plastic recycled 3D glasses. To add insult to injury, the theater asks for the glasses back to be recycled so they can charge someone else another $3 to $4 for the same glasses without giving you any incentive. Perhaps a coupon for a few dollars off at the “overpriced” concession stand, maybe?

Example of Active 3D glasses

In an answer to the in-theater 3D experience, the electronics manufacturers have given us 3D TV’s to enjoy in our very homes. While some are very excited about this new concept of home entertainment, there are those who are a bit more standoffish. This may be due to that fact that, like the theaters, special 3D glasses are required to enjoy this feature. Now we get to the confusing part… for you see, in order to “SEE” this wonderful third dimension, most TV manufacturers use what is called an “active” display which requires glasses that can run you somewhere in the area of $100-150 per pair. This is due to a “shutter” system built into the electronics of the glasses that make the lenses flash in a sequence that when synchronized with the image flashing on the TV, presents the information to your left eye, than your right, then left, then right… and so on. This happens so fast that the human eye does not see the “flashing” on the glasses nor on the TV’s screen. Your brain takes this alternating sequence of images and puts them back together as a 3D picture. Viola!

Example of Passive 3D glasses

Now, this is not the only 3D option out there. Some manufacturers use a different method similar to the movie theaters. This is called “passive” 3D. Unlike sunglasses, which are designed to block light equally from both eyes, passive “polarized” 3D glasses block different kinds of light from each eye, creating the illusion of depth. Since each lens is blocking out light, you’re technically not getting a full 1080p image for each eye, where as “active” maintains a 1080P output. The big PLUS to the “passive” option is that glasses are basically the same thing you get at the movie theaters. With this being a low cost factor for most manufacturers, you can find a lot of bundles being offered that include several pairs of glasses.

My advice for anyone thinking about purchasing a new TV is to go to their local electronics store to see for yourself how the two options look to you. Many stores have working demos so you can judge for yourself. Yet don’t expect too many knowledgeable answers from the associates there (something we have unfortunately all come to realize). They seem to be concentrating more on selling extended warranties and signing up new store credit card users than knowing the differences and options of their TV merchandise. Do make use of readily available information from Electronics review sites such as CNET.com, ConsumerReports.org, and others prior to making your trip to the store. It will empower you to make the best hands on decision both in terms of price and technical know how.

What’s been your experience with 3D Televisions?