The 10 Best Active 3D Glasses
From Passive To Active 3D Glasses
Also known as shutter glasses, active 3D glasses display stereoscopic 3D images to each eye individually.
Both anaglyphs and polarized 3D glasses represent passive 3D technology, meaning that they both leverage the filtering of color and images to display a 3D scene on screen.
If you recall the anaglyph age of 3D entertainment, then those thin, flimsy cardboard glasses with red and cyan lenses probably come to mind. By allowing a person's eyes to capture two different angles of the same image, or two different images entirely, these red and blue lenses trick the viewer into perceiving a three-dimensional scene through a visual color filtration process. Different from anaglyphs, polarized 3D glasses deceive the eyes into seeing a 3D image by restricting the amount of general light that enters both eyes, regardless of color. These glasses usually have a yellow tinge to them.
With the use of polarized glasses, the screen presents a viewer with two separate images through orthogonal polarizing filters, which are built into the glasses themselves. This use of polarization to create the illusion of depth is also known as stereoscopics. Both anaglyphs and polarized 3D glasses represent passive 3D technology, meaning that they both leverage the filtering of color and images to display a 3D scene on screen. But what if you want a more fulfilling viewing experience that includes the full color spectrum without any filtering at all? You'll need a pair of active 3D glasses to accomplish this.
Also known as shutter glasses, active 3D glasses display stereoscopic 3D images to each eye individually. While the image intended for the left eye is being displayed, the view from the right eye is blocked and vice versa. This shuttering action shifts the view between the right and left eyes very rapidly so that the brief interruptions do not interfere with the viewer's perceived joining of two separate images into one 3D image on the screen. But how does a simple pair of glasses accomplish this? Using liquid crystal technology, each eye's glass becomes opaque when voltage is applied to it, but it then remains transparent when the voltage is absent.
Most active 3D glasses receive their power from a battery or USB connection and are controlled by a timing signal that allows them to alternately block one eye. This blocking action occurs in synchronization with the refresh rate of the viewing screen to which the glasses are connected. They can be connected to the screen through either wired or wireless (infrared and radio frequency) signals, depending on the entertainment setup you have.
So what gives active 3D glasses an edge over their competition? For one thing, they are color neutral, meaning that the glasses are capable of presenting the full color spectrum to the eyes. This minimizes the annoyance experienced with colored tinges of yellow, blue, or red to simulate a 3D viewing experience. Active shutter glasses can also display viewing content in full high-definition resolution (1080p) without the loss of quality because the screen's images are not being overlaid on top of one another to simulate three dimensions. Finally, active 3D technology is typically compatible with projection, plasma, and LCD televisions.
A Brief History Of Active 3D Glasses
Although the concept of 3D viewing may seem like a modern invention, the concept has been around for a long time. In 1838, English scientist and inventor Charles Wheatstone invented the stereoscope for displaying three-dimensional images. It was a rather clunky-looking machine equipped with pop-up mirrors or lenses. Soon after, Scottish physicist Sir David Brewster streamlined Wheatstone’s device by removing its mirrors and making use of prisms to combine dissimilar images, thus bringing about the lenticular stereoscope. Operating much like a pair of binoculars, the lenticular stereoscope became the first portable 3D viewing device.
McAllister's early design featured LCDs mounted to a small cardboard box with duct tape.
The active 3D shutter system, upon which its respective glass system is based, first appeared in 1922 and was referred to as the Teleview 3D system. It was installed at the Selwyn Theatre in New York City and featured several screenings. The system operated through the running of right and left-eye prints using a pair of interlocking projectors with their shutters being out of phase. Each seat in the theatre had its own viewing device equipped with a quickly-rotating mechanical shutter that was synchronized with the projector shutters.
Liquid crystal active 3D shutter glasses were invented in the mid-1970s by Stephen McAllister of the Evans and Sutherland Computer Corporation, which now focuses mostly on the graphics for digital planetarium and cinema shows. McAllister's early design featured LCDs mounted to a small cardboard box with duct tape. These types of shutter glasses quickly proliferated into the gaming industry by the 1980s with the earliest known application being the SegaScope 3-D (paired with Sega's Master System).
This early form of active 3D glasses used a motorized rotating disc with transparencies for shutters. By the year 2000, several companies offered stereoscopic liquid crystal shutter glasses kits for Windows PC applications and games, but these quickly fell out of favor as the display market shifted away from cathode ray tube (CRT) monitors.
Today, some of the most cutting-edge forms of active 3D glasses come from companies like Samsung and leverage the same lens and frame technology currently designed for glasses used by NASA.
Choosing The Right Pair Of Active 3D Glasses
When shopping for a 3D television, one should be aware that some active 3D glasses will be optimized for the particular technology. For example, some glasses are specially designed for projector televisions, while others will work best for LCD or LED televisions. Depending on the 3D television you choose, it will often come with an appropriate pair of 3D glasses. This is an excellent opportunity to ask questions about the types of glasses that are compatible with your equipment, particularly if your television doesn't come with any accessories when you purchase it.
To minimize eye strain, finding a pair of active shutter glasses with a fast response time will be helpful. Some of the best active 3D glasses not only run on independent battery power, but they offer up to 40 hours of operation time before needing a recharge, making them an ideal choice for extended viewing.
Finally, lightweight design and comfort are equally important, since you'll be wearing these glasses for extended periods of time when enjoying your entertainment. The last thing you want is an excessively bulky pair of 3D glasses that give you a headache.