by Oleg Artamonov
12/18/2008 | 09:11 AM
LCD monitors with TN+Film matrixes have been pushing their opponents out of the market thanks to low pricing, so there are very few models with matrix types other than TN+Film available today. And although modern TN matrixes are not as bad as they used to be, I wouldn’t call them perfect as yet. The main problem with them is that the vertical viewing angle is too small. As the consequence, the screen gets dark when viewed from below.
This makes models with PVA, MVA and IPS matrixes even more precious for people who are willing to pay more for higher quality. In this review I will discuss one such option, the 24-inch Dell 2408WFP with an S-PVA matrix. This model represents the development of the 2407WFP-HC model we tested earlier.
Use the following link for a description of our testing methodology, the equipment we use, and for a brief explanation of what the specified and tested parameters of LCD monitors mean: X-bit Labs Presents: LCD Monitors Testing Methodology In Depth. If you feel overwhelmed with the numbers and terms this article abounds in, check out an appropriate section of the mentioned article for an explanation.
You can also view all previous monitor reviews in our Monitors section.
Dell’s monitors of the medium and top segments usually have a recognizable appearance. The 2408WFP is an example of that.
This monitor has a silvery plastic case with a black screen bezel. The exterior design is original, appealing and practical. The monitor doesn’t look bulky or gauche. Moreover, it offers good screen adjustment options.
The pole of the stand is made from a silver-painted steel plate. That’s why it is so slim, elegant and absolutely rigid.
The stand allows you to adjust the height and tilt of the screen, to pivot the screen into portrait mode and turn it around its vertical axis.
The height adjustment is blocked when you lower the screen to the bottommost position. This is handy for transportation – the stand won’t stretch out when you lift the monitor up. To unblock, you must press down on the monitor’s case a little, push the button at the back of the stand, and pull the case up.
When the screen is turning around, the base of the stand remains motionless: the pole stands on a small rotating circle.
The stand can be easily detached. To do that, you must press the button near its fastening point and pull the bottom part of the monitor towards yourself and then up. The monitor supports VESA-compatible mounts, so you can wall-mount it easily.
The 2408WFP offers a generous selection of connectors. You can see them in the photo above (from left to right): a power connector for the monitor, a power connector for mounted speakers (purchased optionally), DisplayPort and HDMI interfaces, and two DVI-D ports.
And that’s not all yet! The monitor also has a D-Sub interface for analog connection to the PC and three interfaces for analog video sources: composite, S-Video and component (YPbPr). Next goes an audio output which may be necessary for a HDMI connection that can transfer an audio stream. The monitor doesn’t have integrated speakers, so it can only decode and output the sound. And finally, there is a USB hub input and two USB ports that can be used to connect your mouse, keyboard or some other peripheral.
Two more USB ports can be found on the left edge of the case. These ports are handy for USB flash drives. There is also a five-format card-reader here. The monitor is unable to show photos or videos from the attached drive directly, so the card-reader only works when you connect it to your PC via USB.
I mentioned a DisplayPort above. It is a new interface connector that is similar to HDMI in specs and appearance. Why is it necessary then? Formally, HDMI is intended for home appliances whereas DisplayPort, for computers. The most significant difference between these interfaces is the cost of implementation. Each HDMI port costs the user 4 cents of licensing fees whereas DisplayPort is free. Moreover, DisplayPort is adapted for controllers of LCD panels. It needs a simpler controller and may eventually replace the LVDS interface currently used in LCD panels of both desktop computers and notebooks.
DisplayPort allows to transmit video content with a resolution of 2560x1600, frame rate of 60Hz and 30-bit color via a 3-meter cable and video content with a resolution of 1920x1080 via a 15-meter cable. It can also transmit 8-channel audio in 192kHz/24bit format and any data (for example, control commands, coordinate data from a touch screen, or even a video stream from a web-camera integrated into the monitor) at a speed of 1Mbps in both directions. Of course, DisplayPort supports HDCP. This standard is designed to be expandable and backward-compatible with previous versions. Particularly, the ability to transmit multiple independent video streams via a single cable can be added to it in the future.
Compared with DVI, the DisplayPort interface has a smaller connector, can transfer audio and video across the same cable, and supports higher resolutions. DisplayPort has a bandwidth of higher than 10Gbps whereas even dual-link DVI has a bandwidth of 8Gbps only.
Although monitors and graphics cards are all going to transition to DisplayPort eventually, there is no urgent need for this interface as yet. The native resolution of the Dell 2408WFP fits within the capabilities of single-link DVI even (a bandwidth of about 4Gbps), and 8-channel audio is not necessary for a monitor that doesn’t have speakers. This interface can be considered as a future-proof measure. If graphics cards transition to DisplayPort in a couple of years, you will be able to use your good old 2408WFP with them without any adapters. But again, DisplayPort doesn’t provide any special advantages today. It is simpler to connect the monitor via DVI.
Some time ago Unified Display Interface (UDI) was also supposed to replace DVI. We shouldn’t worry about a format war, however. Back in 2007 Intel and Samsung left the UDI development group and there have been scarcely any news about UDI since then. A present UDI SIG member, Nvidia has recently introduced a professional Quadro CX card with a DisplayPort interface.
The monitor’s controls are placed in the bottom right of the case. Their light-gray labels are visible even under dim lighting. Quick access is provided to switching the video inputs, to turning on the Picture-in-Picture mode, to the automatic adjustment of analog connection, and to the Brightness setting. The Power indicator is built into the appropriate button. It is not very bright and shines green or amber (in Sleep mode).
Dell’s monitors have a handy design of the case, but the design of their onscreen menu is just the opposite. The menu offers an abundance of setup options but you have to make a lot of button presses to reach some of them.
There is a horizontal strip showing the main menu sections. One problem is that in order to get back to this strip you have to leave the current menu item, browse to the Back item and select it. That’s most inconvenient in a submenu that may contain a dozen options. It would be simpler if the monitor had a dedicated Back button for that purpose.
The first menu screen offers the traditional Brightness and Contrast settings.
The Input Source menu is unlikely to be used often: it is handier to select the input you need by pressing the appropriate button. By the way, when you press it, the monitor doesn’t switch to the next input immediately. Instead, it shows the name of the input for a couple of seconds so that you could quickly browse through to the desired one. This is far handier than when the inputs are switched immediately as in some other monitors, each transition taking a few seconds during which the monitor does not react to the control buttons.
The Preset Modes screen offers a few preset modes. You can choose from gamma (Desktop, Multimedia, Game), color gamut (sRGB) and color temperature modes. Switching them from within the onscreen menu is not handy. Most other monitors have a quick button for that purpose (Samsung’s MagicBright, ASUS’s Splendid, NEC’s DV Mode, etc). The quality of these modes will be discussed in the Tests section.
The selection of the preset modes changes when you use an analog video input. Hue and Saturation settings are available instead of color temperature modes then.
Most of the Display Settings refer to the position of the picture on the screen at analog connection – you don’t need them if you use DVI, HDMI or DisplayPort. I’d like to note the interpolation setting called Wide Mode: this monitor offers a 1:1 mode which is necessary to display 1080p (1920x1080) video properly, i.e. without geometrical distortions.
Here you can also find the dynamic contrast mode (this mode can only be necessary for watching movies, so it is again inconvenient to look for this option deep in the menu) and the zoom setting. The latter can be helpful when you are watching video in 4:3 format – you can zoom into the picture to get rid of the black bands on the sides of the frame.
Interestingly, the Brightness setting is not blocked in the dynamic contrast mode (when the monitor is automatically adjusting the brightness of its backlight depending on the currently displayed image). But its purpose differs: this setting determines the maximum possible brightness then.
The next menu screen refers to the menu itself: orientation, position on the screen, time to display, transparency. The LCD Conditioning option is interesting here. When you select it, the 2408WFP begins to fill the entire screen with solid colors to get rid of any residual images. Such images are not typical of PVA matrixes, so you will hardly need to run this procedure.
The last menu screen contains the parameters of the Picture-in-Picture mode. You can specify the size and position of the secondary window, choose the video source for it, and set up its brightness and color reproduction regardless of the main window settings. These settings are available only if the Picture-in-Picture mode is enabled.
When in this mode, the monitor can show content from one computer and one analog video input but not from two computer or two analog video inputs. You can display the content from the analog input in full screen and the content from the computer input in the secondary window.
Summing it up, the monitor’s menu is rich in setup opportunities but doesn’t have a friendly interface for accessing them. I felt the lack of a Back button when navigating the menu. Then, some modes (the dynamic contrast mode and the image presets for specific applications) are meant for specific situations, for example games or movies, and must be accessed quickly. It is a trouble to turn them on and off from the depths of the menu.
The viewing angles of this monitor are wide – the S-PVA matrix shows its best right away. Subjectively, the color reproduction, backlight uniformity, response time and other parameters of the 2408WFP are good. Color gradients are reproduced perfectly, without banding, at any value of contrast. So, this monitor is free from obvious defects.
I should confess some users have reported that their 2408WFP had a pinkish hue of the screen. I didn’t spot this problem with my sample.
By default, the monitor’s Brightness and Contrast are both set at 50%. I achieved a 100nit level of white by choosing 28% brightness and 35% contrast. The monitor regulates its brightness by means of pulse-width modulation of the backlight lamps at a frequency of 161Hz.
The backlight brightness is far from uniform. The average deflection is 6.1% on white with a maximum of 29.1%. On black, the average and maximum deflection are 4.1% and 22.2%, respectively. The pictures above indicate that the screen is darker on the right. Otherwise, there are no bright or dark spots on the screen. It means that this nonuniformity is not going to be very conspicuous.
The 2408WFP employs lamps with improved phosphors and delivers a color gamut which is larger than sRGB in greens and reds. Note, however, that the color gamut triangle of the 2408WFP is larger than sRGB overall but does not cover the latter. Thus, this monitor is not as good as its sRGB counterparts at reproducing yellow and green-yellow hues.
But again, its red color is just splendid. Extended-gamut monitors with CCFL backlight we have tested so far could only boast a pure green whereas deep red was the prerogative of monitors with LED-based backlight such as Samsung SyncMaster XL24. The Dell 2408WFP breaks this rule. It uses fluorescent lamps as its backlight but its red is far purer than on typical sRGB models.
You may wonder what to do if you want to have ideal color accuracy for sRGB images. After all, most photographs are sRGB-oriented. As you remember, there is a mode called sRGB in the monitor’s menu.
My measurements show that the monitor does try to bring its color gamut down to sRGB, but it doesn’t succeed much. It cannot cover yellows because of the discrepancy between the gamuts and its red is somewhat worse than in sRGB.
So there is only one way left for you to ensure high color accuracy for sRGB photographs. You must use software that can work with monitor’s color profiles and adjust the image according to them. Well, if you buy the monitor for games, movies and text-based applications, its pure and saturated colors won’t be a problem and you can do without a color profile.
The gamma curves look good at the default settings: red and green are almost ideal but the blue curve is sagging a little.
The curves get close to each other at the reduced brightness and contrast but also rise up a little above the ideal curve for gamma 2.2 in the left part of the diagram. In practical terms, it means that darks are displayed brighter than they should be.
The curves have almost the same shapes in the sRGB mode. Their value of gamma is somewhat lower than the required 2.2, making the image brighter than necessary. The deflection from the ideal curve is small, however, so the only real problem with this mode is that the monitor’s effective color gamut doesn’t coincide with sRGB when you enable it.
You can also choose two special modes in the monitor’s menu: Game and Multimedia.
Red and green are oversaturated in the Game mode, making light halftones indistinguishable from each other. Besides, the picture doesn’t have high contrast, and darks are displayed brighter. This may come in handy in dark games where you want to discern an enemy lurking in shadow, but of course this has nothing to do with neat color reproduction.
The Multimedia mode is set up better in terms of color accuracy, but darks are brighter than they should be, again. Red is a bit oversaturated, too. Another problem with these modes is that you can enable them from the depths of the onscreen menu only. It is a bother to get into the menu before and after a game or movie to enable an appropriate mode and then get back to the Desktop mode.
The color temperature setup is good. It is only in the Cool mode that there is a difference of 1000K between the levels of gray. Otherwise, there seem to be no problems here.
Well, there is one problem: the image acquires a pink hue in the Warm and, most oddly, Cool modes. For the other modes the CIE diagram indicates a good balance of gray with minor deviations from the ideal.
The maximum brightness is almost as high as 500 nits although the manufacturer promised only 400 nits. Anyway, you only need 70-120 nits for text-based applications and no more than 200-250 nits for games and movies. The contrast ratio is very good, too. It is just a little lower than 1000:1.
The dynamic contrast ratio (the last column of the table) was measured at the default level of brightness, i.e. 50%. Perhaps this is the reason why the result didn’t make it to the specified 3000:1. The number doesn’t impress when you compare it to the specified dynamic contrast of some other models that can be as high as 20,000:1, but there is no real need for such high values. In fact, the brightness adjustment range of the 2408WFP is quite sufficient for practical purposes. Big numbers produce the intended marketing effect, especially as some makers omit to note that it is dynamic rather than static contrast, but too high fluctuations of the brightness of the screen may be irritating.
The monitor uses a modern S-PVA matrix with response time compensation and behaves accordingly in this test. Its response time average is 8.7 milliseconds (GtG) with a maximum of 14.4 milliseconds. This is not the fastest speed possible, yet it is high enough for games and movies. For comparison, many TN-based monitors with a specified response time of 5 milliseconds are positioned as gaming models, but their effective speed is about 13-14 milliseconds (GtG).
The RTC mechanism is accompanied with errors but their level is low: 3.0% on average and 20.2% at the maximum. Moreover, the errors occur with a limited number of transitions. The corresponding visual artifacts won’t be conspicuous.
The Dell 2408WFP is a good product indeed. It features a neat, attractive and ergonomic design, superb functionality, a generous selection of connectors, a high-contrast S-PVA matrix with good viewing angles, and neat setup. All of this makes it a good choice for both home and office, especially for users who are not satisfied with TN matrixes.
The monitor also offers HDMI and DisplayPort interfaces and an integrated card-reader. It provides problem-free operation with HDTV content in 1080p format. Thanks to its 1:1 interpolation mode, the 2408WFP can show 1080p video on the pixel-per-pixel basis, which is important for people who want to connect a game console or a HD player to it.
There are but few downsides in this model. First of all, its onscreen menu is unhandy. The developer should simplify it and assign certain features to hot buttons. And you may also be disappointed that the effective color gamut in the sRGB mode does not exactly match the standard sRGB color space.