Digital Projectors For Photographers

Mitsubishi PK20 Pocket Projector

We may still call our multimedia productions “slideshows,” but there’s no way anyone will ever confuse one of today’s digital projectors with the slide projectors of yesteryear. Compared to their analog ancestors, they’re quieter, brighter and more versatile—they’re also more expensive, so here’s what you need to know to prepare for your foray into the world of digital projectors.

Projector Types

There are three main types of digital projectors based on how the image is formed and projected. Two use a reflected-light system, the other uses transmitted light.

Digital Light Processing, or DLP, is a reflected-light system built upon an optical semiconductor known as a Digital Micro-Mirror Device. The DMM consists of an arrangement of mirrors, each of which is less than one-fifth the width of a human hair. Each mirror represents one single pixel. A projector with native resolution of 800 x 600, for example, employs 480,000 tiny mirrors.

White light passing through a color filter wheel falls on the DLP chip as red, green and blue light. Each mirror is controlled electronically to regulate how long it’s on or off, as well as the amount of each color of light that’s reflected into the lens and, subsequently, on the screen. This happens so fast that human eyes perceive a full-color image.

DLP mirrors are spaced less than one micron apart, and that minimizes the gaps between the pixels in the projected image. The result is an image that’s virtually seamless and looks sharp and bright at almost any size.

LCD projectors offer certain advantages when compared to DLP projector models with identical specifications. The main advantage is potentially better control over colors. LCD projectors are said to have superior sharpness and better color saturation. On the other hand, LCD models are sometimes weak when reproducing true blacks (and even dark grays).

LCD projectors denoted as LCDx3 (or 3LCD) indicates that they use three separate LCD panels to produce the color image. The three panels represent red, green or blue light, respectively. Light is projected through the panels and into the lens to form the image. Because of this fixed arrangement, LCD projectors are generally considered to have zero geometric distortion (at native resolution) and excellent sharpness.

Casio XJ-S30

DLP and LCD projectors have been competing against each other for years, so which technology is superior? As with all competing standards, each has advantages and disadvantages. Bottom line: Proponents of both technologies have been striving to overcome every shortcoming, so a generic comparison is futile—each continues to improve. Not all brands of LCD or DLP projectors perform the same; the differences are subjective. If possible, evaluate the image that’s projected by the projector of your choice under typical conditions before you buy.

LCOS is a third technology that was largely ignored until recently. LCOS, or Liquid Crystal on Silicon, is moving into the spotlight because Canon engineers have leveraged its advantages while eliminating its major shortcomings. LCOS is a reflective system like DLP and offers a high fill factor, fully saturated colors and zero aberrations. On the downside, LCOS projectors are larger and still more costly. But as you’ll read in the description of the Canon REALiS X600, LCOS just might end up being the best projection technology of all.

Resolution And Brightness

Native resolution refers to the actual physical pixel count. A projector that provides SVGA resolution has 480,000 usable pixels arranged in an array that measures 800 x 600. Maximum resolution indicates the highest resolution a projector can provide. To achieve maximum resolution greater than native resolution, the image is electronically compressed. This compression can have a detrimental effect on image quality; the degree depends on the machine. It’s something you must judge for yourself.

SVGA is just sufficient to properly display digital image files. VGA (640 x 480) is definitely not a good choice. If it’s within your budget, consider stepping up to XGA (1024 x 768). You’ll get 60 percent more pixels. SXGA (1280 x 1024) is the best yet, but it’s costly.

The larger the projected image or the closer you (and your audience) are to the screen, the more resolution you need. A question often arises as to how this compares to 35mm projectors, but unfortunately, a direct comparison isn’t simple because brightness has a strong impact on how people react to the images. In some presentations in which both a 35mm projector and a digital projector were used, we noticed attendees preferred the digital projection because of the brightness.

Resolution isn’t a simple issue, however, as which size is best is somewhat dependent on the viewing distance.

Brightness is measured in lumens. This specification is generally denoted as ANSI lumens to signify that the light output was measured according to the testing procedure established by the American National Standards Institute. Brightness ranges from 1000 to 2000 for most, with the higher number becoming more standard. The advantages of a brighter projector include the ability to overpower ambient room light. For low-ambient or true lights-out productions, you may find that a 1000 to 1500 lumens rating is sufficient. If you project from the back of a big room, you’ll want a 2000 lumens projector.

Sanyo PLC-XU48

Contrast Ratio

This specification indicates the projector’s dynamic range, but be careful. There are two ways to measure the contrast ratio. The so-called full on/off method measures the ratio of light output between an all-white (full-on) image and an all-black (full-off) image. This yields a higher number than the ANSI method and therefore is used by most manufacturers. For DLP projectors, look for a contrast ratio of about 2000:1. For LCDs, 300:1 to 500:1 is standard—higher is better.

ViewSonic PJ400

Zoom Lens

One difference to check as you review projectors is the lens. The lowest-priced projectors often have a fixed-focal-length lens. With such a projector, you can only vary the size of the image if you change the distance between projector and screen.

With a zoom lens, you can vary the projected image size by changing the focal length. How much zoom you need depends on how (and where) you plan to use your projector. A longer zoom range gives you more flexibility when setting up, offering more choices for placement of your projector, and helps you fill the frame even from the back of the auditorium.

Projector Examples

The Canon LV-X6 is an LCD projector with a native resolution of 1024 x 768 and a maximum resolution of 1600 x 1200. It has a genuine Canon 1.6x zoom, a built-in speaker and quiet (25dB) Whisper Mode. The contrast ratio is 500:1, and brightness is 1500 lumens. It has a unique feature that allows you to project on a background that’s not pure white—you can select from several wall color options so that the projector can compensate and make the image appear closer to natural. The estimated street price is $899.

Canon REALiS X600

The Canon REALiS X600 is the world’s first LCOS XGA projector. It stretches boundaries with 3500 ANSI lumens, a 1000:1 contrast ratio and a 1.7x Canon ultra-wide power zoom. Canon has combined the LCOS technology with its proprietary AISYS light engine technology to display images with accurate, uniform color. It offers four color modes, and each can be adjusted in seven dimensions, which means you have up to 28 different custom image modes. Additionally, the projector’s six-axis (RGBCMY) color adjustment allows you to tweak the hue and saturation of each of the primary and secondary colors. With an estimated street price of $2,499, the Canon X600 isn’t for everyone, but if you need to present colors in a uniform and accurate way, Canon’s REALiS series approaches perfection.

The Casio XJ-S30 DLP features a 2x zoom, 2000 lumens output and XGA (1024 x 768) native resolution. It weighs less than four pounds and has a thin, attractive profile. At $1,499, it’s on the upper end of the price spectrum. For $200 more, the Casio XJ-S35 adds a USB port that can be used with the Casio USB Wireless (IEEE 802.11b) Adapter YW-2S for wireless operation.

The Epson PowerLite 76c is a lot of LCD projector at an affordable price. It delivers XGA resolution, 2000 ANSI lumens and a 400:1 contrast ratio. Epson has a strong reputation for high-quality color from its LCD projectors. For an estimated street price of $799, it also offers automatic setup and instant-off functions, so you don’t have to wait while the bulb cools.

The Epson PowerLite 1715c LCD projector, priced at $1,999, is XGA with a 400:1 contrast ratio, is extremely bright (2700 lumens), has wireless capabilities and weighs 3.7 pounds.

If ultra-portability is what you’re after, the Mitsubishi PK20 Pocket Projector will fit on the palm of your hand—it’s less than two inches thick and weighs only 1.1 pounds. It’s a DLP projector that utilizes eight LEDs to generate 25 ANSI lumens. While that figure sounds anemic compared to full-sized models, keep in mind the PK20 is intended for a high degree of portability and close-range use under dark conditions. Native resolution is SVGA (800 x 600), and the contrast ratio is a respectful 1000:1. It also has a slot for an SD card, so you can leave your camera and computer at home. Estimated street price is $810.

The Sanyo PLC-XU48 ($1,199 estimated street price) is a full-featured XGA LCD projector offering 3000 ANSI lumens output, 450:1 contrast ratio and SXGA (1280 x 1024) maximum resolution enhanced by Sanyo’s proprietary DRIT (Digital Realized Interpolation Technology) compression compensation. At six pounds, it’s about the size of an 8½x11-inch notebook, except it’s 2.8 inches thick.

Panasonic PT-LB50SUThe Panasonic PT-LB50SU ($725 estimated street price) offers several convenient features. Its Auto Search function automatically detects what kind of source is connected and begins projection. It also has a Speed Start that displays an image within two seconds of power up. The PT-LB50SU LCD projector has SVGA native resolution, 2000 ANSI lumens and a 400:1 contrast ratio. And it weighs only four pounds.

Sony VPL-EX3

Sony’s offerings in the digital projector category are extensive. The Sony VPL-EX3 is an LCD projector that’s well suited for business use or occasional travel at a scant 6.4 pounds. It provides native XGA resolution, 2000 ANSI lumens and a bright 1.2x zoom lens. It’s a workhorse that comes complete with a remote control and three-year/2,500-hour warranty. Estimated street price is $889.

From ViewSonic, the PJ400 LCD projector delivers portability at a great price. It weighs less than five pounds and has an estimated street price of less than $800. It features SVGA native resolution and 1600 ANSI lumens. Contrast ratio is 300:1. It comes with an outstanding warranty: three years on parts and labor, first-year replacement service. The bulb is covered for a full year, too.