Active or Passive: what type of 3D TV should you buy?

The 3D technology becomes increasingly popular and quality. In recent years lowered equipment prices, the quality increased, experience has become more accessible and available content increased in size. Today, 3D TV with active and passive technology are the most common in stores. But, although the results are quite similar, there are differences that should be considered by the consumer. The DTG Reviews explains the technologies and helps you choose the best option for you.

As 3D functions

The idea is very simple. Angle slightly different images are shown to each eye, so that the brain interprets the image has a volume, as in the real world. This is exactly how the eye works.

Take the test: Focus your vision on a nearby object. Cover one eye with your hand and watch it for a while without moving your face. Quickly, cover the other eye and open the first, still aiming this object. Notice how your vision seems to have changed its location to the object. Now open both eyes and notice how the object appears to have more volume.

As the 3D requires two eyes to be seen, people with monocular vision or certain eye problems may not realize the effect.

Active 3D

The TV with active 3D glasses have batteries and communicate with the device through a wireless connection, usually bluetooth. The lenses act as shutters that synchronized to the television screen, open and close alternately to each eye, while the panel passes the two images forming the 3D in a very fast display frequency.

Thus, while one eye sees an image, the other sees nothing. Then, the other eye sees a different image while the first view is blocked. This happens at such a speed that the brain can not perceive and "think" that the two eyes are seeing different images at the same time, which simulates the three dimensional effect.

It delivers superb picture quality because each eye sees 1,080 lines while image (considering that the content is a high definition media). You also can move up or down the TV level, sitting on the floor, for example, but the effect is lost, since the trick is to present alternate images for each eye.

As against, the opening and closing movement of the lens, although fast, can make a noticeable flicker effect that after extended use, such as when watching a two hours movie, can cause discomfort, visual fatigue and even head pain. The closed lens blocks all incoming light to one eye, then the loss of brightness and image contrast is evident, even if the TV is set to the maximum level of these elements. The battery requires recharging the glasses at some point and extra glasses end up costing expensive, which may limit the fun when you want to join friends and family in front of the TV.

Passive 3D

In passive 3D TV glasses don’t have batteries. Your lenses function as light filters. The TV panel also has a special layer that directs light of each line of the image for each of your glasses, interleaved way. So while half of the image lines is displayed only by the right eye, the other half is viewed only by the left eye.

With this technology, each eye sees half of the image, each from a different angle, and the brain reconstructs the full image, creating the three-dimensional effect.

Since there is no movement of the lenses, no flickering effect, which makes them quite comfortable for prolonged wearing glasses. The loss of brightness and contrast occurs, but is less intense than the previous technology. The absence of free batteries the user needs to recharge them and makes them lighter spectacles, also allowing the sale of the clip-on lens type, which have no frame and can be fitted on common glasses. The price is also an attractive, since liabilities glasses cost a fraction of the price of active glasses, facilitating the fun in large groups.

As each eye sees half of the lines that form the image, there is much discussion about the fact that there is a real high definition on passive 3D. The truth is that only extremely trained eye should notice some loss of detail. The most that can be seen is a slight aliasing on diagonal lines of high contrast, but nothing that really bother. As the glasses are dependent on the light filter that exists on the screen, see it from top to bottom or from bottom to top is usually not a good idea, causing the loss of effect. Ideally, all viewers are with the head positioned at the same height of the center TV screen.

What is most important

The most important when choosing a 3D TV is to evaluate which technologies features make the biggest difference for you. While a person may feel tremendously disturbed by the flickering effect of active glasses, another person may prefer a larger angle of vertical and higher definition image display. The price of the glasses can also be considered if the person intends to use the device with the whole family and friends.

Ideally, the user of new technology can test it before making the purchase. The sensation provided by a 3D TV can only be understood when they watch it, is not something that can be simply explained. Perception is a very private experience.

The trick is to go to a department store and test the technologies, seeking simulate the conditions of your living room, as the height and distance of the sofa in relation to television and the use of high definition media (Blu-ray 3D) to make the most of the effect. Evaluate the pros and cons, choose a device that will meet your need for a good time and enjoy!