A Buyers’ Guide to Electronic Presentation Projectors
Every concept gets the proper attention when it is presented well. Nowadays, presentations can be the best that they can be, thanks to electronic display projectors, a product of modern-day display technology. Making your point more effectively, sending your message with flair, and communicating with impact is easily achieved. All you have to do is to focus on organizing your thoughts and leave the rest to an impressive and impactful presentation.
So what is a projector, and how can you be sure that you’re getting the best of what you need? Presentation projectors currently available are a far cry from the overheads or slide projectors used ten years ago. Today’s projectors are so advanced that a presentation just doesn’t have impact without one.
What you need to know before buying a projector
Projectors are an investment, so before you go on a shopping spree, there are a few basic concepts you need to understand about the machines and how they are marketed. Projectors are categorized by weight, marketed by brightness, hyped by resolution, and sold mostly because of price.
What do I need to know about brightness?
Brightness projectors are expressed in ANSI lumens. ANSI stands for American National Standard Institute, and lumens is a standard unit prescribed as a system of brightness measurement enabling different brands of projectors to be measured and compared fairly.
To obtain the brightness level in ANSI lumens of a projector, the projector projects a white, 4:3 aspect ratio screen, 40″ diagonal in size to a no-gain, non-reflective matte screen. This white screen is then divided into nine equal size rectangles, 3 rows of 3 rectangles, as though one is ready to play tic-tac-toe. Then, the brightness level at the center of each of the rectangles is measured using a light meter. After obtaining nine measurements, they are summed and divided by nine to obtain the average luminance measure. This average luminance measure, expressed in lumens, is the ANSI lumen rating of the projector.
Projector brightness, though one of the most important considerations when buying a projector, is still a rather elusive standard. Because the brightness of a projector is largely a function of its lamp, lens, and the optical engine, it will vary from projector to projector, even in projectors of the same make and model, or in a single projector, depending on the age of its lamp. Projector manufacturers worldwide face this challenge in a very real way – that’s why the brightness specification of projectors are claimed as “typical” and not guaranteed. The brightness specification may vary up to +/- 20 per cent, depending on the luck of the draw. It is not to be used as a hard, factual number, but rather, as a benchmark for fair comparison with other projectors.
Projectors are usually better when they are brighter. But the question of what is bright enough depends on a few factors, including the size and weight of the projector, the room in which it will used, and of course, your budget.
Is it all about weight and brightness?
The above table is merely a guideline for most projectors available today. However, there are a few other features that must also be considered in your purchase decision, which may require a projector of the same brightness at a much heavier weight, and heftier price.
Weight and brightness in a projector is almost always inversely proportional. The brighter you need your projector to be, chances are, the heavier its weight will also be. As your preference turns to lighter weights, the brightness will not be the only feature that may be compromised.
How do you think manufacturers make their projectors small? First, they use smaller, less powerful lamps, and sometimes these lamps are also shorter in life, making it a cost issue to maintain in the long run. Then features are taken away to make it lightweight. In some cases, features that are fundamentally nice to have are also taken away, such as zoom lens, remote control, and various presentation-friendly productivity features. So think twice when you ask for the smallest and the lightest projector. From my experience leading countless presentations, people in my audiences do not complement the size of my projector; they usually praise its brightness and clarity. In other words – performance. Size happens to be a pleasant surprise for them when they find out it is not the size of a Buick, like those used in the movie theater projection rooms.
What about contrast ratio?
For the majority of projector users, brightness is the most important factor, but for someone displaying more movies and videos, contrast ratio is important. Contrast ratio pertains to the ratio of the brightness of the brightest white, versus the darkness of the blackest black. The higher the contrast ratio, the deeper and richer the colors are displayed.
Although there is also an ANSI standard of measuring contrast ratio, most manufacturers opt for the de facto industry standard call the Full ON Full OFF measure. Using the same 40″ diagonal 4:3 aspect ratio screen, a white screen is projected, its brightness measured from the center, and then a black screen is projected, and its brightness measured again from the center – the contrast ratio is the ratio of between the two measurements.
XGA or SVGA? What is resolution and why is it important?
Resolution pertains to the number of picture elements, also known as pixels, that make up your screen area. If you have gone shopping for a digital camera or a desktop monitor before, chances are, you have a basic understanding of resolution. Following is a table of known resolutions in computer graphics:
It helps to understand that computer screens are fixed in size; therefore, a higher resolution does not make the display any bigger, it simply shows more information in smaller sizes. So the idea that “the higher the resolution, the better” does not necessarily apply. Sometimes a higher resolution backfires by making the objects you intend to display look smaller on the screen. Don’t be enamored by higher resolution if it is not necessary for your intended applications.
Unlike your desktop CRT monitor, a projector is a single resolution display device, and this singular display resolution is called its “true” or “native” resolution. Although it will also display other resolutions, it does not display them in true fidelity. In other words, if you buy an SVGA projector, it only displays SVGA resolution with a true one-to-one pixel ratio, enabling your displayed screen to be at its sharpest and clearest possible. When you display a VGA, XGA, or even SXGA screens in an SVGA projector, they will still be displayed, but there will be some compromise due to the expansion or compression involved.
For example, if you’re displaying a VGA (640 x 480) computer screen on an SVGA native projector, the image will not be big enough to completely cover your entire screen. Therefore, the projector expands the image proportionally to fill the screen. Similarly, if an XGA (1,024 x 768) computer screen is being projected using an SVGA native projector, the higher resolution screen has to be compressed to fit into the SVGA (800 x 600) screen, otherwise, portions of the higher resolution screen will get cut off from the display.
So what projector resolution should you buy? Well, once again, that depends on what you’re trying to present most of the time. It helps to know that the most popular resolution level nowadays are XGA (1,024 x 768), followed closely by SVGA (800 x 600). XGA is popular because almost all high-end notebook computers come standard with XGA screens, and most turnkey application software packages use XGA as their standard resolution. This means that if you are projecting computer applications, XGA would be necessary to show a full screen of the application. SVGA, on the other hand, remains to be quite popular because of its price. Entry-level notebook computers still come with SVGA screens, and almost all of Internet homepages are designed using SVGA as standard resolution.
So what resolution is the best one for you? Here’s the rule of thumb. If most of what you present are PowerPoint or similar computer-generated slide presentations, then you can save some money by buying an SVGA notebook computer and projector. But if you’re doing more than PowerPoint, then you must consider at least XGA resolution. If you already own a notebook computer, then always match your projector resolution to your computer. The table below may help you quickly decide what resolution is best for you.
What are the available technologies that power electronic projectors?
A word about LCD and DLP technologies…
The two most popular technologies fueling the growth of electronic projector displays are miniature Liquid Crystal Displays (LCD) and Digital Light Processing, or more commonly known as DLP, made by Texas Instruments. There are other technologies but they are not yet broadly available.
LCD projectors are usually 3-panel poly-silicon based LCD projectors. Although there are still single-panel LCD projectors available at very low cost, my advice is to keep them where they are – in the warehouse at their final resting place. Three-panel LCD projectors on the other hand, are a different story. They are the best LCD projectors available nowadays at reasonable and affordable prices.
Patterned after the idea of the 3-gun CRT (another dinosaur of a projector that’s near extinct in the world of business projection), a 3-panel LCD projector uses a red panel, a green panel, and a blue panel to create the image to be projected on the screen. Because images are formed on three separate LCD panels put together in a U-shape formation, each panel needs its own light source, thus a maze of mirrors are formed in the projector to reflect light to all three panels from one single lamp. Because of this, the LCD projector usually needs a little bigger form factor to accommodate its light and optic engine. However, LCDs, due to its transmissive nature, usually show better colors.
The best way to imagine an LCD projector at work is to visualize it with an image forming electronically on each of the three LCD panels as though they are digitized slides. Then with light blasting through them, a converged image is projected through the lens, and magnified on the screen.
DLP is a reflective technology based on digital micro-mirrors on a chip. On each DLP chip, there are hundreds of thousands of micro-mirrors. Each mirror represents one pixel, therefore an XGA projector will have 1,028 mirrors in one row, with 768 rows of them. To form an image, each mirror tilts to a varying degree, thus reflecting the proper amount of light for each pixel represented in an image. A constantly, fast-turning glass wheel with red, green, blue, and clear transparent colors gets in the way to form the colors needed.
Texas Instruments invented this chip, giving way to the invention of ultra-portable and micro-portable personal projectors. But notwithstanding mobile projectors, the DLP chip also powers the engines of a lot of other display products such as projection televisions, cubes that form video walls, and even large-venue movie projectors. DLP projectors are usually small and light. And because of its reflective nature, a DLP projector with similar lamp power and size as its LCD counterpart, would most likely be brighter and yield a higher contrast ratio.
Between the two most popular technologies, LCD and DLP, which is better? To be honest, it’s a toss-up. LCD and DLP technologies undergo constant improvements, and there are benefits to both. So do some side-by-side comparisons and buy what your eyes tell you is better.
How are colors evaluated in projectors?
Color is very important. Not only in projectors and all display systems, but life in general. Can you imagine a world without color televisions, color film, color cameras, color printers, or color presentations? Unfortunately, as important as color is, it’s often not scrutinized enough when buying a projector. Many buyers rush to the conclusion that brightness is the only thing, and then they buy based on brightness more than anything else.
Many projectors quest for high brightness when showing a white screen, which causes them to over-compensate on blue, which typically makes a word processor or a spreadsheet look good. Unfortunately, flesh tones then look like they’ve been through the wash cycle.
When buying a projector, examine how each model lets you adjust its colors. Are there adjustments for each of the major color inputs: red, green, and blue? Higher end projectors are even more sophisticated. More expensive models allow you to adjust color down to its gamma level. However, inexperienced users tend to mess up a picture more than they can help it when they really do not understand gamma adjustments. Mitsubishi has developed their proprietary ColorView Natural Color Matrix, which lets you adjust the red, green and blue, and also incorporates the primary print colors of yellow, cyan, and magenta. Each of these six colors can be adjusted independently to increase the hue of the colors intended, without skewing the other colors. Furthermore, a saturation adjustment allows users to simply intensify certain colors more precisely, bringing their images into vivid and vibrant pieces of art. The adjustments available from the menu are so user-friendly that one can easily get the desired color output quickly.
How about color temperature? Can the color temperature be adjusted to shine best with the lighting of the room where the projector is to be used? Or can the color temperature be tuned to suit the kind of applications mostly shown using the projector? In rooms with high ambient lighting or incandescent lighting, a higher color temperature may be desired to show colors more vividly. However, in rooms where the primarily lighting is white fluorescent, it’s best to tune the projector with a low color temperature, which makes the picture look warmer, despite being flooded by bluish white fluorescent lighting.
Color temperature has a profound effect on how your applications show on screen as well. If your applications are shown mostly on a white background, or varying shades of white, a higher color temperature enables your white to look somewhat whiter. However, if you use intense displays involving natural colors and flesh tones, then a warmer color temperature setting is usually recommended.
Is there a standard color format or profile upon which a projector should be evaluated?
Color standards or profiles are usually available for niche and graphic-intensive applications. But with the advent of different computer display technology, the demand for such a color standard is increasing because different devices show colors differently, and it’s always a challenge to have colors in a CRT-based desktop monitor look similar when shown on a projector.
A few years ago, Microsoft announced their endorsement of sRBG (standard RGB). sRGB is a color profile based on the International Electrotechnical Committee’s (IEC) standard 61966-2-1, developed for use as a standard for colors displayed in CRT-based monitors. Since CRT color standards have been used as the de facto standard for most computer displays, including LCD-based desktop monitors, sRGB makes it easy for the computer community to use this as a color standard without having to readjust the many types of computer displays.
The sRGB color profile has recently been adopted by a few projector manufacturers, including Mitsubishi Electric. These projectors access the sRGB color mode through the menu. No further color adjustments are needed when the sRGB color mode is selected. When used with an sRGB computer system, the user is confident that colors are displayed as accurately as they are intended to be. Moreover, images projected with an sRGB compliant projector show exactly the same color tones as when they are viewed through any other sRGB compliant devices.
With a projector, the sRGB color profile provides an added benefit when showing video movies. Video colors shown in an sRGB projector are much warmer, and flesh tones look much better. The overall display performance of a LCD projector or DLP projector also tend to look much like a picture displayed by a CRT projector, which video buffs say is best when viewing color videos.
So, when buying a projector, don’t forget to check out the colors. You may not need them for powerpoint slides, but if you ever want to show color pictures or videos in your presentations, color should be scrutinized. Many inexpensive projectors do not provide very good colors. A projector is always worth its value when you spend just a tad more to ensure that it displays colors accurately and vibrantly.
A word about video presentations
Many times, projector buyers set out to buy a projector, and then get a demo of purely computer displays. Video, although very important, usually gets set aside. So when doing a demo, ask for video demonstrations in addition to computer displays. All projectors perform at a similar level when using computer displays. Video playbacks usually provide you with the tool to weed out the mediocre projectors from the really good ones.
When doing video demonstrations, watch dark scenes in suspense thrillers – these scenes look good in projectors with high contrast ratios. Watch scenes with natural colors such as green meadows, blue skies, and waterfront or beach scenes – these scenes let you gauge the accuracy and vibrancy of colors. Watch shows with fast moving action scenes, and finally, watch the end of the movies and observe how the rolling credits look in your projector. A good projector will handle these without any lines or noisy artifacts.
Take me shopping for my projector!
So now you’re a projector expert and are ready to wheel and deal to get the best projector at the best price. Where should you buy and from whom? If you’re a first time buyer, it is best to do some research and side-by-side comparisons. Buy from someone who can demonstrate all the features in a projector. Professional audio-visual dealers are usually the best people from which to buy, because they have experienced different requirements and can show you a few different models. Most computer resellers, or Internet web sites are not equipped to handle such an old-fashioned way of selling because they operate on relatively low margins: they are good places to go when you’re buying your second or next 20 projectors for your next building.
More importantly, it is also best to keep an open mind. When looking at ultra portable, or micro-mobile projectors, give yourself an allowance of up to two pounds. This won’t cause you any shoulder pains, but you’ll be surprised with the amount of brightness, and the richness of features you can get by allowing yourself to look at models that are one or two pounds more.
In terms of brightness, it is also wise to give yourself an allowance of up to 500 ANSI lumens. 500 ANSI lumens difference in brightness may not be visibly different to the naked or untrained eye in a semi-lighted environment or totally dark room. However, the units may actually have better contrast ratio and colors, not to mention cost-savings of a few hundred dollars.
Now that you’re armed with all this information, you should be able to choose the best projector with the best value from the best vendor, and use it happily ever after, if not for five to six years.