REVIEW: Dell 1907FP (s) Part 8

Image Quality

In the 1907FP, Dell incorporates a TN panel by Lite-On. TN panels can reproduce only 6 Bits per RGB color, corresponding to a total of 262,144 colors. VA and IPS panel are capable of 8 Bits per RGB color, thus amounting to a total of 16.7 million colors.

TN panels make use of the so-called dithering, which enables them to display similarly many colors as other panels. Thanks to this technology, the color space is extended to 16.2 million colors. However, the standard color space used in the PC sector comprises 16.7 million colors, and also the color accuracy of TN panels cannot quite cope with the one achieved by VA and IPS panel.

Dithering sometimes fails to reproduce exact color tones within gradients. This is why in subtle color gradients one can always observe banding effects to a varying degree (visible, less visible and sometimes hardly visible at all). Thus, dithering has a significant impact on picture quality. The better it is implemented, the better the resulting image quality.

Considering the fact that it is a TN panel display, the results we obtained from reviewing the Dell 1907FP attest to remarkable picture quality. Subtle linear and radial revealed hardly any banding at all. Admittedly, in grey scales, the banding effect is more pronounced; when put in perspective, however, the quality is quite outstanding.

In addition, the effect that is frequently encountered on TN panels, where dark content details tend to drown in a goo of near-black tones is hardly visible at all on the Dell 1907FP.

In order to measure color space and color fidelity of the Dell 1907FP, we first calibrated the display by using the Colorimeter Silver Haze Pro (x-rite Model DTP94) and the iColor Software by Quatographic. The results we obtained are illustrated by the following charts.

Calibration:

	Reference	Measured
Gamma	2.2	2.2
Kelvin	6500	6495
cd/m2	140	141

Measurement charts: Click illustrations for enlarged view and explanation

Dell specifies the maximum brightness of the 1907FP at 300 candelas per square meter (cd/sqm). We crosschecked these values and measured a minimum of 50 cd/sqm, while the maximum was 249 cd/sqm. Thus, the display's actual capability falls short of the official specs by a significant 51 cd/sqm.

While the fact that Dell's brightness specification is misleading deserves criticism by all means, it should also be noted that 249 cd/sqm is still more than enough to get ideal results. In practice, given normal lighting conditions, we consider a brightness level of 140 cd/sqm to be the ideal setting. The Dell 1907FP reaches this amount of luminosity at an OSD brightness setting of 50 - 55 percent.

According to the manufacturer, the contrast ratio of the 1907FP is 700:1; this promises good black level, which we were also able to confirm in practice.

According to the monitor's technical specs, the viewing angles of this TN panel amount to 140 degrees horizontally and 130 degrees vertically, - while both values refer to a contrast ratio of 10:1. Although this might not sound much at first, the Dell 1907FP's picture still remains amazingly stable when viewing from the side. And from above, too, the picture appears to be quite good. It is not until one looks from below that changes in color start becoming apparent quickly, showing heavy color shifts at increasingly higher viewing angles.

Left picture: viewing angle from the right hand side; right picture: frontal view.

The pictures above illustrate the integrity of the picture quality respectively when viewed from below and from above.

<< < 4 5 6 7 8 9 10 11 > >>

No Comments available

you have to be registered and actual logged into the forum to write comments.
go to the forum!

Advertising