3D TVs Explained: How They Work and What You Can Watch

The Current Landscape of 3D Television

When considering a new television purchase, it's highly probable you'll encounter 3D-capable models. This isn't necessarily due to a strong consumer demand for 3D functionality, but rather because 3DTVs often feature superior display technology compared to standard HDTVs.

Understanding the Varieties of 3DTV Technology

There's often some ambiguity surrounding the different types of 3D television available. This article aims to clarify these distinctions and provide a comprehensive overview.

Several technologies are employed to create the 3D effect. Each approach has its own advantages and disadvantages regarding image quality, cost, and user experience.

Common 3DTV Technologies Explained

• Active Shutter 3D: This system utilizes active shutter glasses, which rapidly alternate between blocking the left and right eye's view in synchronization with the TV's display.
• Passive 3D: Passive 3D TVs employ polarized lenses in both the television screen and the glasses. This method is generally more affordable and doesn't require batteries for the glasses.
• Autostereoscopic 3D: This technology creates a 3D image without the need for glasses, using a lenticular lens or parallax barrier to direct different images to each eye.

The choice between these technologies often depends on individual preferences and budget considerations. Image quality and viewing angles can vary significantly between each type.

It’s important to note that the availability of 3D content has decreased in recent years. However, many 3DTVs still offer excellent upscaling capabilities for standard 2D content, enhancing the overall viewing experience.

Types of 3D Display

As a well-known figure – perhaps apocryphal – once suggested, not all 3D displays are the same. There are, in reality, three fundamental categories of 3D display technology currently utilized in televisions, monitors, and portable gaming devices.

Autostereoscopic Displays

Autostereoscopic displays don’t require the user to wear special glasses. Instead, they utilize a variety of techniques to project different images to each eye. This creates the illusion of depth without any additional eyewear.

• Lenticular Lens Displays: These displays use a series of tiny lenses to direct light to specific viewing angles.
• Barrier Grid Displays: A barrier grid, consisting of vertical stripes, is placed in front of the display to separate the images for each eye.

The viewing angle for autostereoscopic 3D is often limited, and image quality can sometimes be reduced. However, the convenience of a glasses-free experience is a significant advantage.

Active Shutter 3D Displays

Active shutter 3D technology relies on specialized glasses that rapidly alternate between blocking light to each eye. The display synchronizes with the glasses, presenting a different image to each eye in turn.

This method delivers a full-resolution 3D image, offering a high-quality viewing experience. However, the glasses are battery-powered and can be expensive to replace.

Passive 3D Displays

Passive 3D systems employ polarized glasses, which are significantly less expensive than active shutter glasses. The display presents two different images, each polarized in a different direction.

Each lens in the glasses filters light polarized in a specific direction, ensuring that each eye sees only its intended image. While generally more affordable, passive 3D often results in a reduced vertical resolution.

Understanding these different 3D display types is crucial when selecting a device. Each technology offers a unique balance of image quality, cost, and convenience.

Active Shutter 3D Technology

Active shutter 3D displays operate by presenting images alternately for each eye. A frame intended for the left eye is displayed, followed by a frame for the right eye, and this process is continuously repeated.

Specialized glasses, equipped with LCD lenses and synchronized with the display’s refresh rate, are used in conjunction with these televisions. These glasses rapidly switch between obscuring the view for each eye.

The left lens becomes transparent to show the left-eye perspective, then quickly darkens as the right lens opens to reveal the right-eye view. This alternation creates the illusion of depth.

While this rapid switching might seem disruptive, it typically occurs at a rate of approximately 60 times per second, making it largely imperceptible. However, some viewers may perceive a subtle flicker.

Prolonged use can occasionally lead to headaches in sensitive individuals. This is a known potential drawback of active shutter systems.

Identifying Active Shutter TVs

Active shutter televisions are identifiable by the need to power their glasses. These glasses either require recharging via a USB connection or utilize small, replaceable batteries.

Compared to other 3D glass types, active shutter glasses are generally heavier and more expensive. The cost of an extra pair can easily exceed $50.

Advantages of Active Shutter Displays

Active shutter technology is often regarded as delivering superior 3D image quality. This is because each eye receives a fully distinct image, minimizing image crosstalk.

Image crosstalk, or “bleeding,” occurs when both the left and right eye images are visible simultaneously, reducing the 3D effect. Active shutter systems effectively eliminate this issue.

Furthermore, active displays maintain higher brightness levels. This is because only one frame is displayed at any given moment, unlike passive 3D which shows both images concurrently.

Passive (Polarised) 3D Technology

Passive 3D displays function by presenting both the left and right image frames concurrently. Each frame undergoes processing through a distinct polarising filter. This process aligns the light waves, restricting their propagation to a single direction.

Subsequently, when these light waves encounter 3D glasses, they interact with another set of polarising filters. Only the light intended for the appropriate eye is then permitted to pass through.

Image Quality and Brightness

The visual fidelity of passive 3D is generally considered lower than active 3D. This is due to its relatively basic methodology, which limits the achievable depth perception. Images can also appear somewhat unclear.

Furthermore, blocking half of the emitted light from the television results in a noticeably dimmer picture compared to active 3D displays.

Advantages of Passive 3D

A significant benefit of passive 3D is the affordability of the glasses. Often, televisions are supplied with multiple pairs – potentially up to eight.

These glasses also eliminate the need for batteries, relying solely on the principles of physics for their operation. This makes them a cost-effective and convenient option, particularly in households with children where breakage or damage is more likely.

Lenticular (Glasses-Free) 3D Technology

Lenticular technology powers the latest generation of 3D televisions that eliminate the need for specialized eyewear. This technology is also found in existing consumer electronics, such as the display screens on 3D cameras and the Nintendo 3DS handheld gaming system.

The principle behind lenticular displays is similar to the optical illusion seen on "hologram" cards once commonly included in breakfast cereal boxes. Changing your viewing position relative to the card reveals different images.

How Lenticular 3D Works

Lenticular 3DTVs function by directing light at precise angles. If a viewer were to close one eye and move around the television, they would perceive alternating left and right image frames.

This is a unique approach, but it inherently limits the optimal viewing positions. Watching from unconventional angles – such as lying down or tilting your head – significantly degrades the 3D effect.

Limitations and Current Quality

As 3DTVs utilizing this technology were anticipated to launch around early 2013, it was important to understand the constraints related to fixed viewing angles.

Despite the appeal of a "glasses-free" experience, the current 3D image quality produced by these devices is generally considered subpar. Even Twentieth Century Fox has cautioned against expectations of high fidelity.

Key Considerations

• Viewing Angles: Optimal 3D effect is limited to specific positions.
• Image Quality: Current lenticular 3D displays often exhibit reduced clarity.
• Technology: Relies on directing light to create the illusion of depth.

2D to 3D Conversion and Emulation

Many 3D televisions feature a 2D to 3D conversion function, designed to transform standard 2D broadcasts into a 3D experience. It is strongly recommended to avoid utilizing this feature. This process relies on algorithms to analyze the image, attempting to differentiate between elements in the foreground and those in the background.

Subsequently, the television generates a 3D illusion by artificially separating foreground objects, thereby simulating a feeling of proximity. Humans possess a remarkable ability to perceive depth even with monocular vision; closing one eye still allows for a reasonable estimation of an object’s depth based on prior knowledge of its form, size, and past positioning.

However, replicating this cognitive process with a computer in real-time presents significant challenges. A comparable technique demonstrated in Photoshop previously yielded similarly underwhelming outcomes. The inherent difficulty lies in accurately analyzing a scene and determining the precise location of each object within it.

Regardless of the sophistication of the analysis, the resulting 3D effect will invariably be substandard. It’s akin to attempting to recreate the nuances of a live orchestral performance from a heavily compressed 64kbps MP3 file – a task that is fundamentally impossible.

Therefore, it is advisable to only activate 3D mode when viewing content that has been natively broadcast or recorded in 3D. Enabling it for all content will likely result in a diminished viewing experience.

What Entertainment Options Are Available for 3D Televisions?

Broadcast Television and 3D Channels via Cable: The BBC has actively broadcasted in 3D this year, covering events like Wimbledon Tennis and the Olympic Games. Sky also provides a 3D channel [Broken URL Removed], though subscription costs can be substantial.

3D Blu-ray Discs: A 3D-compatible Blu-ray player is required for playback. Alternatively, a Playstation console can also function as a 3D Blu-ray player.

Playstation 3 Capabilities: Sony is at the forefront of 3D entertainment, with its Playstation 3 supporting both 3D Blu-ray discs and a wide range of 3D games.

Xbox 360 Support: The number of games offering 3D functionality on the Xbox 360 is currently limited. Call of Duty: Black Ops 2, released in November, is among the titles with 3D support.

PC Gaming in 3D: Utilizing drivers from TriDef.com allows for 3D gaming on a personal computer. However, it’s important to remember that these drivers won’t enhance a computer’s processing capabilities. If a PC struggles with standard gaming, it will likely be unable to handle 3D gaming effectively, as it requires approximately double the processing power to render two separate displays.

This article has outlined the technology behind 3D TVs and key considerations for potential buyers. It is hoped that this information will facilitate a well-informed purchasing decision and a greater understanding of how these televisions operate and the content available for them.

Feedback and suggestions are welcome. However, please refrain from asking if a standard laptop or non-3D television can play 3D movies, as they are not capable of doing so.