In part two of our series, we continue to examine and evaluate the image and video picture quality produced by mobile devices. We looked at MP3 and portable video players in part one. Here we take a look at four high-end smart phones: the Motorola Q, Nokia N80, Palm Treo 700p, and RIM BlackBerry 8700.
Like the MP3 players, cell phones have rapidly evolved into multimedia devices with color displays that let you navigate on-screen menus, view digital photos, and watch movies and TV shows. But, how good are the tiny screens on smart phones? Can they produce excellent picture quality comparable to your HDTV or computer monitor? And how do they compare to the players in Part I? To answer these questions, I used the same high-powered analysis methods we use for testing and evaluating high-end HDTVs at DisplayMate Technologies (www.displaymate.com).
The Smart Phones
Smart phones are versatile devices, but they lack some of the features of the MP3 and portable video players examined in Part I. All of the players have large hard drives and TV Out that let you display photos and videos on a TV. These smart phones have neither. However, in addition to USB support for downloading content, they have flash memory cards, cameras, and Wi-Fi. And, of course, they have their networks, which can deliver photos and videos via Web browser, e-mail, messaging, and streaming.
While the BlackBerry 8700 does not have a reputation as a multimedia device, it actually delivers excellent picture quality. One very useful enhancement program for the BlackBerry, which we used extensively, is Ascendo Photos (www.ascendo-inc.com). It allows photos (any jpg, bmp, or gif) to be transferred to the phone directly from a PC via USB, and then shown with its own viewer. Otherwise, content on the BlackBerry can only be downloaded via the phone network.
Table 1 (below) shows the most important display specifications for the four smart phones. We will examine the photo and video quality of the phones displays in depth.
Dont be turned off by the relatively low resolutions of these phones, because it is the pixel density, or Dots Per Inch (DPI), that determines how sharp images appear, and these are relatively high DPIs. For reference, a 19-inch LCD monitor has a DPI of 86. The number of Screen Colors that a display can produce is frequently misinterpreted as an indication of its color gamut (the range of colors that it can produce). It has nothing to do with the gamut, but rather specifies the number of possible intensity levels for each of the red, green and blue primary colors, which can vary from 32 to 256 levels.
Table 1: Display Specs
Nokia N80 | Motorola Q | Palm Treo 700p | RIM BlackBerry 8700 | |
Screen Size | 2.1 inches | 2.4 inches | 2.5 inches | 2.6 inches |
Resolution | 416 x 352 | 320 x 240 | 320 x 320s | 320 x 240 |
Dots Per Inch | 260 | 170 | 180 | 150 |
Screen Colors | 262K | 65K | 65K | 65K |
Content Sources | 2 cameras, Flash, Network, USB, Wi-Fi | Camera, Flash, Network, USB | Camera, Flash, Network, USB | Network, USB |