4. Preliminary Testing

HP allowed us to briefly test the DreamColor’s brightness settings during a demo event. We took luminosity readings on a Gossen meter in two conference rooms — in one we measured 64 spots on a white screen with fluorescent lights on in the room, in the other we measured 64 spots on a dark screen with lights off (though there was some ambient light in the room). For both tests, we set the monitor on its sRGB preset and cranked the brightness up to maximum. Though some monitors can take time to warm up and reach full brightness, we didn’t have the luxury of time during these tests and so conducted our readings only a moment after increasing the brightness settings.

Brightness Chart

Contrast Chart

Note that our mean brightness reading came to 173.4 candelas per meter squared, while the mean contrast reading came to 680:1. HP’s spec sheet for the product lists maximum brightness at 250 candelas per meter squared, while the contrast ratio is listed at 1000:1 (with a caveat that all performance specifications represent typical specifications provided by HP’s component manufacturers and that actual performance may vary).

After sharing with HP the readings from our luminosity meter, the company informed us that the demo-unit pre-production DreamColor monitors we tested were operating with a “bug” in the sRGB preset’s brightness settings. According to the company, on the sRGB preset, brightness could not reach the expected 250 candelas per metered square, which might explain our substantially lower (albeit still significantly bright!) mean readings of 173.4, and the subsequent contrast ratio substantially below the spec-listed 1000:1. Final versions of the DreamColor monitor will ship with the brightness bug fixed, according to HP.

Other factors besides the sRGB brightness bug may have played a role in making our test results different from HP’s spec sheet. For example, our testing environment in the DreamWorks conference room surely introduced more variables than HP allows in its own testing facilities. However, a standard conference room is likely more similar to a home environment or small office (where many would-be buyers of the DreamColor might do their work) than a pitch black lab with no windows. Also, as noted, we didn’t allow ample time for the monitor to warm up after increasing the brightness settings.

Testing variables aside, the HP DreamColor monitor is one of the brightest we’ve seen, and one of the most constant, with brightness relatively stable across the screen. For contrast, the 23" Apple Cinema Display’s spec-sheet lists 400 candelas per meter squared as the maximum brightness.

The contrast ratio across the DreamColor’s screen was a bit more erratic, though the average matched the highest-end gaming laptops and surpassed many top-of-the-line consumer monitors (the Apple Cinema Display spec maxes out at 700:1, and tests even lower). We don’t consider absolute blacks a necessity in a monitor — after all, it is not a plasma television — a larger color band seems far more important.

We look forward to spending more time in our lab with the final version of the DreamColor monitor.