Dream Screens

Does Digital Matter?

Conventional wisdom holds that digital-to-digital signals produce better image quality than signals converted from analog to digital and then back to analog. But does that claim stack up? Since some of the LCD monitors we tested offer dual analog and digital interfaces, we compared their performance in both modes. We expected to see a marked difference, but that's not the way things turned out.

The five monitors we looked at for this roundup that offer both digital and analog output are the Compaq TFT5010, the NEC MultiSync LCD1525X, the Philips Brilliance 150P, the Princeton Senergy 560, and the ViewSonic ViewPanel VP150m. (The last two didn't make our Top 10 chart.)

Two of these five, the Philips and the Compaq, displayed text and graphics at about the same quality in both digital and analog modes. In a "blind" test, two teams of testers looked at these monitors in both analog and digital mode but voiced no real preference for either one. The NEC MultiSync LCD1525X achieved similar results. In sum, you'd probably be just as happy with these LCDs' analog image quality as you would with their digital output.

On the other hand, two dual-input LCDs--the Princeton Senergy 560 and the ViewSonic VP150M--did show a noticeable difference in their digital and analog image quality. The VP150M earned an adequate score for the quality of its digital images--the same score earned by the Compaq TFT5010. But in analog mode, the VP150M delivered some of the lowest image scores we saw for both text and graphics.

The Princeton Senergy 560 showed the biggest difference. The 560's digital image quality captivated our testers, earning the highest image-quality score of all the dual-input LCDs. The monitor's analog image quality, however, was deemed the worst of the entire bunch. So, in the case of the Princeton, a digital graphics adapter might just come in handy. Considering the 560's affordable $899 street price, it could prove a sweet entrée to the world of pure digital display.