Overview of Features and Specifications

Before we get to the specifics of the Gateway FPD2485W, it's important to have some understanding of what makes for a good display. There are many factors to consider, and intended use will play a role. Here's a brief overview of the commonly quoted specifications and what they actually mean.

Brightness: This is generally a well understood measurement. Brightness is typically measured in candelas per square meter (cd/m 2 ) or "nits". Having a brighter display is usually preferable to most people, but there is definitely such thing as a display that is too bright. LCDs have really caused some confusion in this area, as brightness levels have shot up in order to compensate for poor black levels. 100 nits is pretty typical of most CRTs, give or take, and 400 nits is probably as bright as you would really want for prolonged computer use. Staring into an ultra-bright display for hours a day can be uncomfortable, so unless your computer environment tends to be brightly lit you'll almost certainly be reducing the maximum brightness. Depending on the technology in use, it's also worth mentioning that running a display at maximum brightness levels can cause the backlights to burn out quicker.

Contrast Ratio: Contrast ratio is often grossly misunderstood due to misleading marketing. Getting a good contrast setting from displays is further complicated by the lack of proper adjustment options on many devices, and personal preference plays a part. The contrast ratio is simply the brightness level of pure white divided by the brightness level of pure black. In the real world, contrast ratio is always infinity - black is 0 and dividing by 0 is equal to infinity. Contrast ratios became meaningful with displays like LCDs where pure black (0 cd/m 2 ) was not possible, and higher ratios are generally better. The problem with such a generalization is that a display with 1000 nit whites and 1 nit blacks has a 1000:1 contrast ratio, while a 100 nit white and 0.1 nit black produces the same contrast ratio of 1000:1. It is usually better to get a high contrast ratio by having very dark blacks than by having overly bright whites, but the brightness and contrast ratio should be viewed as a combined unit where you want to keep the brightness somewhere in the range of 200-400 nits depending on environment while still achieving a high contrast ratio.

Response Time: Pixel response time gained popularity after problems with early LCD displays. Maybe it was discussed in the early days of computers, but most CRTs were simply fast enough that no one thought about pixel response times. The response time is the time required to change from one color to another color; most companies rate it as the time to stabilize to within 5% of the target color. The problem with response times is that you also have to know whether you're changing from black to white/white to black (TrTf), or whether you're looking at gray-to-gray (GTG) times. GTG transitions are more common than black/white transitions, but both are important - consider how often you see black text on a white background, for example. Unfortunately, response times are another widely abused specification, with many companies only reporting the best case scenario rather than an average response time. Also note that TrTf would be roughly twice the GTG time for any given panel, since GTG only involves one transition while TrTf requires two. It is important to know whether a display will bother you with "smearing" - i.e. slow pixel response times - but that ends up being mostly a personal preference with modern LCDs.

Viewing Angle: Viewing angle is the angle at which you can still see the image "properly". This is doubled, since viewing angle actually describes the arc in which you can still see the proper output, and horizontal and vertical components are often listed separately. For computers, viewing angle isn't very important at all, as you're almost always sitting in front of the display. TVs where you may be watching with a group of people can use a larger viewing angle, but even then anything more than a 90 degree viewing angle should be sufficient - after all, it's not fun to watch TV from an oblique angle even if you still see the proper colors. Unfortunately, as with many of the other specifications, what qualifies as a "properly viewable" image is up for debate. In some cases, companies have been known to rate viewing angle as being able to see 10% of the requested brightness. Our display reviews will list the manufacturers' stated viewing angles, but we will only bring it up as a cause for concern if we find the viewing angle to be extremely narrow.

Color Depth: Depending on the sort of work you're doing, the need for high precision color depths varies. Most displays have a set number of intensities that they can display for red, green, and blue, and this is almost always a power of 2. (Technically LCDs function by passing varying light intensities through a color filter, but the net result is the same.) A 6-bit display can show 26 (64) different intensities while an 8-bit display can do 28 (256) intensities. With separate RGB values, you can then cube that number to get the total color space. 643 = 262,144, 2563 = 16,777,216, etc. While most people will agree that 6-bit is insufficient - even with dithering to approximate a larger color space - anything more than 8-bit per channel output starts to become more hype than substance. Lower color depths can also result in banding, where the transitions between various colors become visible even when they're not supposed to be.

Color Accuracy: Out of all of the factors to consider when looking at a display, this is going to be one of the most important. Unfortunately, accuracy is rarely a reported specification, in part because it is far more difficult to measure but also because it can vary from display to display. Getting accurate colors from a display can be achieved in several ways. The first is to basically just go with whatever defaults an LCD comes with, which usually means that the colors will be wildly inaccurate. A slightly more sophisticated approach is to use software to try and help you calibrate the contrast and brightness, and you can take it a step further by adjusting color intensities as well. This is what is known as "calibrating by eye" and is what most people end up doing. The best way to calibrate your display is to get a hardware colorimeter and appropriate software to help you adjust the various display settings, but unfortunately this costs money and most people don't care enough about color accuracy to go that far. Image professionals, on the other hand, would be well served by purchasing some form of color matching/calibration hardware/software.

Other Factors: Arguably the most important factors for a lot of people when looking at a new display are going to be the size and the price. All of the specifications may look great, but if a display costs several thousand dollars the target market is greatly reduced. Likewise, a decent display sold at a very competitive price is going to be far more attractive to a lot of people. That said, it's not too surprising that lower-cost displays tend to vary much more in terms of overall quality - one unit might produce great colors and the next could be highly inaccurate. Part of the reason for this is that quality control isn't as much of a concern. Build quality is also often affected by lower costs, with some cheap displays coming with very flimsy stands and/or enclosures. LCDs in particular can also develop pixel defects - individual pixels or sub-pixels that are stuck in a single position, resulting in either black dots or bright dots - and manufacturer warranty and replacement policies are something else to we will evaluate. We will also look at the ability of the LCDs to function in non-native resolutions, although most people will want to run at native resolution so this isn't a huge concern. On-Screen Displays (OSDs) and any other noteworthy features will also be mentioned.

Now let's take a look at the features and performance of the Gateway FPD2485W to see how it fares.

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  • strikeback03 - Monday, February 26, 2007 - link

    thanks, that makes sense. I assumed the LUT was applied to everything the video card sent to the monitor. However playing with my calibration settings in the GretagMacbeth software and also with the nVidia controls provided in their settings package did not touch the video image.

    My current desktop monitor absolutely destroys blacks in it's out-of-the-box configuration. Calibration can make most stuff OK (not great) but since it does not affect video, movies such as the Matrix or V for Vendetta are unwatchable.
    Reply
  • JarredWalton - Thursday, February 22, 2007 - link

    I didn't notice any issues with blacks being "crushed", but there were some other issues I'll address shortly in regards to colors. Reply
  • chizow - Thursday, February 22, 2007 - link

    Crushed blacks are a pretty bad problem with miscalibrated displays. Basically if you use the provided calibration software EzTune and calibrate the display based on what the captions tell you, you'll get an overly dark setting with really high relative contrast. In games and movies, the result is horribly crushed blacks with no detail/difference in blacks and brain-searing light/particle effects. For instance, in Dark Messiah, I felt like I was running around with a blindfold on...except for the blinding light coming off my Lightning Shield, which I avoided using at all costs. Reply
  • Justin Case - Friday, February 23, 2007 - link

    Note that most lossy video compression algorithms will eliminate more detail from very dark (or very bright) colors than from midtones, so if a DVD appears to have crushed blacks, that could be just a poor encode.

    Most 3D games have a local gamma setting, so a wrong value there can also make things look bad.

    Having said that, poor loss of detail and posterization in dark areas is a problem with some LCD panels.
    Reply
  • Justin Case - Thursday, February 22, 2007 - link

    Laptop panels are typically picked for their low power consumption, not color accuracy, which makes those values a bit odd. What model is your laptop? And have you measured other monitors with the same calibrator?

    Anyway, simple calibrators won't measure things like color variation with angle of view, light bleed, etc. (which aren't issues for CRTs, but are for LCDs), so the deviation alone isn't a complete measure of the overall image quality.
    Reply
  • strikeback03 - Friday, February 23, 2007 - link

    Thinkpad T43 with the Flexview (IPS) screen. There is some slight contrast change with viewing angle, but it's the best I have seen in a laptop. Other displays I have checked include my desktop LCD (cheap, with predictably bad colors, which is why I'm looking to replace it), a cheap old CRT (not very good), and a few ViewSonic CRTs at work (good results from calibration on all). Reply
  • JarredWalton - Friday, February 23, 2007 - link

    You should see the results from an older laptop I have. Even calibrated, dE is still a whopping 7.8! There are a few colors (blue and yellow I think) where I couldn't get dE to anything lower than 16-20. Heh. If you've got a display on a laptop that can get an average dE of anything less than 2.0, you're doing *VERY* well! My future laptop reviews will take a closer look at the laptop LCD quality.... Reply
  • StevenG - Thursday, February 22, 2007 - link

    Some sites have reported extensively on the issue of input lag with LCDs. They have found that if you drive a CRT and an LCD at the same time, the image on the LCD will often lag the CRT by 1 or more frames. So what you are seeing on screen with an LCD is actually up to 50 or so ms behind the image that is being produced by the video card. This is one reason why I still don't use LCDs for gaming (the other reason being low refresh rates, which means a low frames/second limit if you enable vsynch - I refresh at 100 Hz at 1280x1024 on my 21" CRT, and there isn't an LCD on the market that can match that).

    I would like to see Anandtech explore this issue of LCD lag.
    Reply
  • Justin Case - Thursday, February 22, 2007 - link

    You have a 5:4 aspect ratio CRT? If not, you should be using 1280x960. If you pick 1280x1024, most games will assume you're using a 5:4 monitor (LCD), and the image will be slightly distorted (vertically compressed). Reply
  • JarredWalton - Thursday, February 22, 2007 - link

    Refresh rates are one of the advantages of CRTs that nothing else is currently able to match, unfortunately. I wish we could get 100 Hz refresh rates on LCDs, if only to avoid reduce the appearance of screen tear with vsync disabled, but the digital connection precludes that option for now.

    As for input lag, the pixel response times can make the LCD always appear one frame behind what is supposed to be shown, i.e. the GPU sends frame 1, and then 1/60 of a second later it sends frame 2, etc. The LCD receives frame one and the pixels start to transition, but the transition takes anywhere from 2-20ms (depending on colors and LCD). If we just say it takes ~16ms, that's one screen refresh. I've heard other LCDs may buffer input so that there's an additional lag, but if so I can't say that my eyes are sharp enough to detect it.
    Reply

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