Projector Tech 101: How Sony's 2020 Home Theater Projectors Advance The State of the Art

We live in a golden age of video content, with access to a multitudinous amount of new movies and bingeable series emanating from a seemingly inexhaustible number of streaming services. This cornucopia of video content is rich in detail and diversity, not only plot and character but in picture quality. Creators, knowing we both consume and dissect their creations like never before, competitively strive to fill each frame with increasingly innovative and breathtaking visuals that can only be appreciated in the highest resolution and on the largest canvases possible.

For 70 years, Sony has been synonymous with pushing the envelope in all aspects of video quality and innovation, from creation to reproduction, from lens to living room. Almost everything we watch is affected by Sony technologies in some way. Sony is a content producer through Sony Pictures, Sony Television, Sony Animation and Sony PlayStation. On the video production side, Sony's Venice Digital Cinema Camera and its BVM-X300 Mastering Monitor are utilized by most major content producers. As the lead developer of Blu-ray, Sony pioneered digital video compression technology. From its Trinitron, WEGA and premium XBR CRT TVs, and now through its BRAVIA and MASTER Series flat panel TVs, Sony displays remain the standard against which all video reproduction innovation is measured.

Home cinema projection represents the culmination of all of Sony's decades-long video reproduction experience and innovation, all with the goal of ensuring that a content creator's intent is faithfully reproduced.

Sony first demonstrated its commitment to and leadership in innovative home cinema projection in 2003 with the Qualia 004, its first 1080p SXRD projector. Then, in 2011, Sony again demonstrated its projector preeminence when it introduced the VPL-VW1000ES, the world's first native 4K consumer home theater projector, setting the 4K transition firmly in motion.

Projector Panel and Chip Innovations

Sony's newest home cinema projectors—the native 4K-resolution VPL-VW715ES, VPL-VW915ES, and flagship VPL-GTZ380—emanate from insights the company has gathered from working with content creators, consumers, and key customers in training and simulation, entertainment venues, corporations, museums and planetariums.

At the heart of these projectors are two key technologies: the company's own SXRD—Silicon Crystal (or X-tal) Reflective Display—panel technology, and the new X1 for projector processor family.

SXRD overcomes the most glaring deficiencies in fixed-panel projector technologies. SXRD's densely-packed LCoS (Liquid Crystal on Silicon) panels have a high 93% fill factor, meaning that 93% of the on-screen image is made of pixels and only 7% black lines separating the pixels. By comparison, competing 3-panel LCD projectors exhibit a fill factor closer to 70%. The result for SXRD is vastly reduced "screen door" effect. SXRD also delivers fast response/low latency, and offers longer operating life and more stable color. Beyond these benefits, Sony's proprietary SXRD imaging chips employ tighter engineering standards than most LCoS imagers. Notably, contact divots and beveled edges are removed, which improves native contrast by ensuring that light is reflected more uniformly.

Powering the picture enhancements contained in these latest Sony home cinema projectors are the X1 for projector and X1 Ultimate for projector processors, new optimized-for-projector versions of Sony's acclaimed BRAVIA TV video X1 processor. The prodigious data processing power of these chips renders real-time frame-by-frame or even individual object-based enhancement, resulting in true high-dynamic-range imagery with texture, color, contrast and realism not previously available in other home theater displays.

X1 for projector powers three distinct and proprietary Sony image enhancement technologies:

• Dynamic HDR Enhancer makes bright scene highlights brighter and dark scenes darker, and delivers the best contrast performance when viewing HDR content.
• Digital Focus Optimizer applies digital correction to achieve optimum image sharpness from the optics, even in corners.
• Super Resolution Reality Creation enhances the detail and color when scaling lower-resolution content to 4K.

X1 for Projector Processor

Sony's projector and display engineers have some added incentive to deliver the ultimate realistic viewing experience—pleasing the company's movie, TV and video game creators by accurately translating their visions from the set to the settee.

With its decades of computing experience, Sony has been able to develop processors which offer the best performance on the market today. In 2015, Sony unveiled its cutting-edge X1 processor for the company's Bravia TVs. Sony's more advanced X1 4K HDR Ultimate processor followed two years later, quickly followed by the next-generation 4K HDR Processor X1 Extreme and X1 8K HDR Ultimate.

But home cinema projectors present a host of specific processing challenges that differ from LCD or OLED flat screen displays. For instance:

• Projectors have typically lacked the ability to dynamically modulate brightness aside from the use of a mechanical iris, a limitation that is now being addressed by dynamically responsive laser light sources.
• TVs generally output more light than projectors, which directly impacts how HDR content created for television displays is reproduced.
• Projector contrast performance is dependent on unknown variables that include the environment, screen size, screen material/gain, and throw distance.
• Along with their limited dynamic range compared to TVs, lamp-based projectors more quickly and inconsistently lose brightness over their bulb's lifespan.

To address this added workload, Sony's new X1 for projector processor in the lamp-based VPL-VW715ES and laser-driven VPL-VW915ES is twice as powerful as its Bravia counterpart. X1 for projector analyzes each frame via advanced algorithms to cut noise, boost detail, smooth frame rates, and, by controlling the projector's dynamic iris and laser (where applicable), intensify contrast and produce deeper black levels. The X1 Ultimate for projector processor, an even more powerful version used in the GTZ-380 laser projector, allows for more granular "object-based" adjustments within the frame.

In each case, the resulting image reflects Sony's decades-long commitment to advanced image processing, and the company's dedication to faithful reproduction.

Dynamic HDR Enhancer

One of the inherent limitations of projectors is their limited dynamic range compared to direct-display TVs. Typically, either black level or color saturation at peak brightness must be sacrificed. Additionally, high-brightness projectors sacrifice color range and color accuracy in the pursuit of lumens.

Without advanced processing and a clear understanding of the creator's intent, reproducing HDR content with a projector is not an easy task. With its decades of experience, Sony is uniquely positioned to understand the unique characteristics of projector technology, and the ways and means to overcome and exploit them.

Sony's proprietary Dynamic HDR Enhancer software in the VPL-VW715ES and VPL-VW915ES helps achieve optimal projector HDR performance. Thanks to the processing power of X1 for projector, it synchronizes precise mechanical iris adjustments, subtly calibrated laser light output (in the case of the VPL-VW915ES), and frame-by-frame digital tone-mapping to overcome projector dynamic range limitations. The system maintains blacks at the appropriate level and color saturation in peak highlights by analyzing each frame, adjusting the signal to ensure that the darkest and brightest elements are maintained relative to each other to more faithfully recreate the creator's intent.

The VPL-GTZ380, meanwhile, takes advantage of the extra power in the X1 Ulitmate for projector processor to offer Object-based HDR Remaster, in which each individual object in the frame is independently analyzed. With more information about the frame to work with, a more accurate representation of the creator's intent is realized.

Technically and philosophically, the degree of image adjustment is governed by Sony's long experience with content creators and the intent to render emotionally satisfying images inside the inherent brightness limitations attendant to projectors. Tone-mapping, used in virtually all HDR projectors, is the process by which HDR content mastered for brighter television displays is re-interpolated to fit within the constraints of the projection display. Without this process, most bright highlights would vastly overpower the projector's peak luminance capabilites and be "clipped," resulting in a loss of contrast and detail in those areas.

Tone-mapping and clipping can also be combined to achieve the desired goals for the image. In this case, some of the bright content just outside the display's peak luminance limit is "rolled-off" to retain its detail while content far outside is clipped. Consumers are often confused by this concept and believe that any clipping is bad and that 100% tone-mapping is ideal. However, given the limited contrast range of a projector, this approach results in a mathematically accurate but artistically bankrupt reproduction that fails to viscerally move the viewer as the artist intended. Sony's Dynamic HDR Enhancer follows this combined approach that uses tone-mapping but limits its effect (by also including roll-off) to ensure that the creator's intent is maintained.

This artist-driven philosophy for HDR is followed in all of Sony's current HDR projectors, including predecessors to the new 2020 models, although, as noted above, the execution varies based on the processor used and whether the projector has a lamp or laser light source, or one of these combined with a mechanical iris to help control light output.

Digital Focus Optimizer

The benefits of all the digital processing and enhancements produced by the X1 for projector processors would be hampered if not for Sony's expertise in lenses and a recently developed Sony technology, Digital Focus Optimizer.

Aspherical lenses and elements are used to direct light from a projector squarely onto the screen. Regardless of the quality of the lens, however, distortion and some degree of softening can occur in fine detail at the edges and in the corners of a large image. Digital Focus Optimizer is a cost-effective method of reducing inherent minor lens distortion through processing, rather than resorting to a much more expensive lens.

The key to Digital Focus Optimizer is Sony's long familiarity with the custom-designed lens that was specifically developed for use with its 4K SXRD panels and has been employed for some time in most of its home cinema projectors. Company engineers have spent years observing how different portions of this lens affect the image. With Digital Focus Optimizer, the projector is able to determine from the lens shift and zoom settings where the light is actually passing through the lens. By then analyzing every pixel of an image with X1 for projector-powered algorithms, the software can anticipate any inherent optical degradations in advance and perform processing to improve focus, even in typical problem areas like the corners and extreme edges of the image.

The result is that, with the Digital Focus Optimizer, image quality is actively refined and corrected throughout the viewing experience, ensuring content always looks tack-sharp. Sony's top Home Cinema projectors, which utilize the more sophisticated and highly regarded ARC-F lens, also feature a version of Digital Focus Optimizer based on similar principles.

Super Resolution Reality Creation

Sony's long and pioneering history in picture-enhancement processors actually has its roots with the introduction of Digital Reality Creation in 1997. Today's execution is still founded on the simple idea that not all content is created equal. There are vast differences on how and when video or film is shot, stored, sourced and accessed. These differences can be even more profound today following the shift from older analog to digital video technology, and more recently, from physical discs to streamed media. An even greater challenge for projectors, with their large picture size, is compensating for the vast differences between content shot in 4K and material shot in 1080p/2K (or even lower) resolution that must be scaled up to fill out the pixels on a native 4K imager.

Sony's solution to accurately displaying this vast array of content is its Super Resolution Reality Creation digital signal scaling and noise reduction technology. Employing a similar database-driven approach to that found in all Sony displays, each pixel in each frame is run through pattern-matching and recognition algorithms. The pixels are compared horizontally, vertically, diagonally, and temporally to differentiate objects from noise, grain, and compression artifacts, identifying and eliminating any unwanted elements. Only after objects have been identified and optimized are images enhanced and then upscaled to 4K.

Compensating for and achieving just the right level of adjustments is a moving target. The Super Resolution Reality Creation patterning database was compiled over a decade, and is updated via OTA firmware when necessary to make sure colors, contrast, and real-world textures remain as true as the day the images were captured.

All Sony projectors use this frame-by-frame analysis against a pattern database, but as with Sony's Dynamic HDR Enhancer, there are different executions for Super Resolution Reality Creation based on available processing power. More robust processing allows for smaller objects to be parsed from each other to deliver more granular results. The Object-based Super Resolution Reality Creation driven by the X1 Ultimate for projector processor in the VPL-GTZ380 utilizes a dual database and can more readily identify differences in smaller objects, such as film grain and noise, allowing the projector to retain the former and eliminate the latter with greater accuracy.

New Advanced SXRD Panels for the Breakthrough VPL-GTZ380

Sony's flagship home cinema projector, the VPL-GTZ380, is unique to Sony's SXRD models and rare among all high performance home theater projectors thanks to its ability to output 10,000 lumens, at least four times the brightness of the average projector and about twice as bright as an average flat panel LCD TV.

To Sony, a projector capable of driving light output that high was necessary to satisfy its most demanding commercial as well as consumer customers. In working with key customers, Sony identified an opportunity to create a projector that not only outputs a tremendous amount of light, but also do so while accurately maintaining color and faithfully reproducing the most challenging content.

SXRD's high fill factor and superb native contrast mentioned earlier provide a solid foundation for such a projector. But to achieve its ultimate light output goals, the company developed a smaller 0.74-inch native 4K SXRD panel that features a new liquid crystal material to dramatically improve light stability and durability. A side benefit of the small panel size is that it allows for a relatively tight footprint for such a bright projector.

To these SXRD panel upgrades was added the even more powerful X1 Ultimate for projector processor and, critically, a third laser to Sony's usual two-laser array. Along with the two blue lasers found in prior projectors with Sony's Z-Phosphor laser engine, the VPL-GTZ380 boasts a dedicated red laser diode to drive deep red performance that was previously only achievable with an internal color filter that reduced brightness.

It is the combination of all these technologies and upgrades that enables the VPL-GTZ380 to not only produce its rated 10,000 lumens of brightness, but to do so while achieving full DCI-P3 color space with no filter requirement that reduces the light output. At the same time, the projector delivers a 16,000:1 contrast ratio while retaining deep blacks. The end result is a breakthrough flagship projector that provides mission critical picture quality for commercial applications, as well as best-in-class consumer home theater performance.