Apple has quietly upgraded its high-end 30-inch Cinema Displays.

It has upgraded the brightness of the display to 400 cd/m2 from its previous 270 cd/m2.

Contrast ratio has also been slightly improved, from 400:1 to 700:1. (Data for the previous model Cinema Display has been confirmed using technical specifications still hosted on Amazon's US store).

Apple's giant display recently beat Dell's UltraSharp 3007WFP 30-inch monitor in a comparison test on CNet, despite Dell's display being cheaper (Apple's 30-inch display costs £1,799, Dell's costs £1,467, both prices include VAT).

CNet editors concluded: "Apple trumped the Dell in our DVD-playback test, displaying less digital noise and more-realistic skin tones, and it won the more technical rounds, with more-vivid colours and better greyscale differentiation. This is the monitor of choice, especially if you own an Apple computer, since the Apple OS provides additional configuration options."

High-resolution displays such as the 30-inch Apple Cinema HD Display can result in "measurable productivity and efficiency gains", according to a Pfeiffer Consulting report (PDF).