Wednesday, May 30, 2007
Hi-Tech Studio: Digital Photo Gallery
Go beyond the conventional and display your work with a flat screen or a projector
Another interesting way to display images in your gallery is with a projector. A few years ago, the only models that would do your images justice were extremely expensive and usually big and bulky. Like everything, the current models are better, smaller and less expensive. Projectors come in two basic technologies, DLP and LCD, both of which have strengths and weaknesses. Here's a quick rundown on each.
Digital Light Processing, or DLP as it's better known, is a system that's built upon an optical semiconductor known as a Digital Micro-Mirror Device (DMM), a chip that was invented by Dr. Larry Hornbeck at Texas Instruments in 1987. 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 a native resolution of 800 x 600, for example, employs 480,000 tiny mirrors.
White light passing through a color filter wheel falls on the surface of the DLP chip as red, green and blue light. Each mirror is controlled electronically to regulate how long they are on or off, as well as the amount of each color of light that's reflected into the projection lens and, subsequently, onto the screen. This happens so fast that the human eye perceives a full-color image—16.7 million colors, as a matter of fact.
One reason why DLP outshines all other projection systems is called “fill factor.” The 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 primary advantage is lower cost, although the price differential is narrowing. LCD projectors are usually denoted as LCDx3 (or 3LCD), which 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. Not all LCD and DLP projectors are created equal, however, so compare the specifications—and prices—carefully when making your purchase decision. If you've owned an LCD projector in the past, you may be pleasantly surprised how much better the current crop performs.
LCD Vs. DLP
This battle has raged for the past several years—which technology is superior? As with all competing standards, each has its 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. So if at all possible, carefully evaluate the image that's projected by the projector of your choice under typical conditions before you buy.
LCD projectors are said to have superior sharpness and better color saturation, while DLP projectors deliver truer blacks and better contrast. Ultimately, it's a subjective decision that only you can make.
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