ViewSonic LS740HD: A Deep Dive into Laser Projection Technology

The world of visual displays is constantly evolving, and projection technology is no exception. For years, traditional lamp-based projectors dominated the market, but a new contender has emerged: the laser projector. The ViewSonic LS740HD is a prime example of this exciting technology, offering a compelling combination of brightness, longevity, and versatility. Let’s explore the science behind this projector and why it represents a significant step forward in projection technology.

Inside the ViewSonic LS740HD: Key Features and What They Mean

The LS740HD boasts a range of features designed to deliver a superior viewing experience. At its core, it’s a 1080p (1920 x 1080) resolution projector, meaning it displays images with sharp detail and clarity. The 5000 ANSI lumens brightness rating indicates its ability to project bright images even in rooms with ambient light, making it suitable for well-lit conference rooms or classrooms. Perhaps the most significant feature is its laser phosphor light source, which offers a dramatic improvement in lifespan compared to traditional lamps – up to 30,000 hours in Eco Mode. This translates to years of use without the hassle and expense of bulb replacements.

Laser Phosphor Technology: How it Works

Traditional lamp projectors generate light by passing electricity through a filament, much like an incandescent light bulb. This process produces a broad spectrum of light, but it’s also inefficient, generating a significant amount of heat and consuming a lot of power. The lamp’s brightness also degrades over time, requiring periodic replacement.

Laser phosphor technology takes a different approach. Instead of a filament, it uses a blue laser diode as the primary light source. This blue laser beam is directed at a spinning wheel coated with a yellow phosphor material. When the blue laser light excites the phosphor, it emits yellow light. This yellow light, combined with some of the original blue laser light (which is often separated using a dichroic filter – a specialized mirror that reflects certain wavelengths of light and allows others to pass through), creates the white light needed for projection. This white light is then further processed to create the red, green, and blue components necessary for a full-color image.

The advantages of this system are numerous. The laser diodes are incredibly energy-efficient and have a much longer lifespan than traditional lamps. The brightness remains consistent over the life of the projector, and the color gamut (the range of colors that can be displayed) is often wider, leading to more vibrant and realistic images.

DLP Technology: Painting with Millions of Mirrors

The ViewSonic LS740HD utilizes Digital Light Processing (DLP) technology, developed by Texas Instruments. DLP technology is based on a unique chip called a Digital Micromirror Device (DMD). This DMD is covered in millions of tiny, microscopic mirrors – each mirror representing a single pixel in the projected image.

These mirrors are incredibly small – smaller than the width of a human hair – and they’re mounted on tiny hinges that allow them to tilt back and forth thousands of times per second. When a mirror is tilted towards the projection lens, it reflects light and creates a bright pixel on the screen. When it’s tilted away from the lens, it reflects light away, creating a dark pixel. By rapidly switching between these “on” and “off” states, and by varying the amount of time each mirror spends in each state, the projector can create a full range of grayscale shades.

To produce color, the light from the laser phosphor light source passes through a color wheel (in a single-chip DLP system, like the one likely used in the LS740HD) or is split into red, green, and blue components before hitting the DMD (in a three-chip DLP system). The mirrors then reflect the appropriate color light to create the final image. One small disadvantage is what is known as the “rainbow effect”. A small percentage of the population are sensitive to this. It is caused by the sequential color updating. The viewer’s eyes see sequential flashes of red, green, and blue.

The result of this intricate process is an image that’s incredibly sharp, with excellent contrast and minimal motion blur. DLP technology is also known for its “sealed chip” design, which helps to prevent dust from accumulating on the imaging chip and degrading the image quality.

Beyond the Specs: Real-World Benefits

The technical specifications of the LS740HD translate into tangible benefits for users. The long lifespan of the laser light source dramatically reduces the total cost of ownership. Businesses and schools no longer need to budget for frequent lamp replacements, and home theater enthusiasts can enjoy years of worry-free viewing.

The high brightness ensures that presentations and videos are clear and visible, even in rooms with windows or bright overhead lighting. The excellent contrast ratio (3,000,000:1) means that blacks are deep and dark, and whites are bright and pure, resulting in a more dynamic and engaging image. The stable brightness, thanks for the laser technology, also means there will be no degradation of light and colours.

Addressing the Elephant in the Room: Potential Drawbacks

While the ViewSonic LS740HD offers a compelling package, it’s important to acknowledge potential drawbacks. Some user reviews have mentioned an intermittent “orange flicker” or “orange glitch.” This issue doesn’t appear to be universal, and ViewSonic support has reportedly suggested returns or exchanges for affected units. The exact cause of this issue is unclear, but it could be related to a software glitch, a problem with the color wheel (if present), or an issue with the power supply or signal processing. Potential buyers should be aware of this reported issue and consider purchasing from a retailer with a good return policy.

It’s also worth noting that the LS740HD, while boasting impressive specifications, may not include features found on some higher-end projectors, such as 3D support or HDR (High Dynamic Range) compatibility. The built-in speaker, while functional, is unlikely to provide a cinematic audio experience, so external speakers are recommended for home theater use.

Installation Flexibility: Setting Up the LS740HD

One of the key advantages of the LS740HD is its installation flexibility. The 1.3x optical zoom allows you to adjust the image size without physically moving the projector, making it easier to achieve the perfect image size for your screen. Horizontal and vertical keystone correction, along with four-corner adjustment, allows you to correct for image distortion if the projector is placed off-center or at an angle. The LS740HD even supports 360-degree projection, meaning it can be mounted in a variety of orientations, including portrait mode, for unique applications.

Connectivity: Getting Your Content on the Big Screen

The LS740HD offers a standard set of connection options, including HDMI and USB. These ports allow you to connect a variety of devices, such as laptops, Blu-ray players, gaming consoles, and streaming devices. The 3.5mm audio jack provides audio output for connecting external speakers or headphones. The projector can also be controlled and managed remotely over a network using Crestron, AMX, Extron, PJ Link, ATEN, and ViewSonic’s vController, making it a good choice for integrated installations.

The Bigger Picture: Laser Projection in Context

Laser projectors represent a significant step forward in projection technology, but they’re not the only option. Traditional lamp-based projectors are still available, and they often come with a lower upfront cost. However, the long-term cost of ownership can be higher due to lamp replacements. LED projectors are another alternative, offering long lifespans and energy efficiency, but they typically don’t achieve the same brightness levels as laser projectors.

For applications requiring high brightness, long life, and low maintenance, laser projectors like the LS740HD are an excellent choice. They offer a compelling balance of performance, features, and value.

Making an Informed Choice: Is the LS740HD Right for You?

The ViewSonic LS740HD is a strong contender in the mid-range laser projector market. Its combination of high brightness, long lifespan, flexible installation options, and versatile connectivity makes it a suitable choice for a variety of applications, including conference rooms, classrooms, and home theaters (for those who prioritize brightness and longevity over features like 3D or HDR).

However, potential buyers should be aware of the reported “orange flicker” issue and consider purchasing from a retailer with a good return policy. They should also carefully evaluate their specific needs and budget to determine if the LS740HD is the best fit.

Digging Deeper: The Science of Color and Light in Projection

The quality of a projected image isn’t just about brightness and resolution; color accuracy and vibrancy play a crucial role. The LS740HD, like most modern projectors, aims to reproduce a wide range of colors, adhering to established color standards like sRGB or Rec. 709. These standards define the specific color coordinates for red, green, and blue, ensuring consistent color reproduction across different devices.

The laser phosphor technology in the LS740HD contributes to its ability to produce a wide color gamut. The precise wavelengths of light emitted by the laser and the carefully formulated phosphor material work together to create a broad spectrum of colors, resulting in more lifelike and saturated images. The DLP technology, with its precise control of light at the pixel level, further enhances color accuracy and contrast.

The way our eyes perceive color is also a factor. The human eye contains three types of cone cells, each sensitive to a different range of wavelengths (roughly corresponding to red, green, and blue). Projectors, by carefully controlling the mix of red, green, and blue light, can stimulate these cone cells in a way that creates the perception of a vast array of colors. This is the fundamental principle behind all additive color mixing, which is the basis of how projectors (and most other display technologies) work.