Choosing a Screen TFT-LCD (08-04-2005)

Choose a TFT-LCD (08-04-2005)

Now that you've made the decision to replace its "old man" CRT for a stylish new TFT-LCD , it is important to know which to choose the monitor that best suits your needs.

There are marketing different brands, models and sizes of TFT-LCD, and at first glance, seem all the same, deceive those who think that. In fact externally be very similar, but may soon begin to realize that there are differences by asking price.

Today is already 17 "displays for approximately 250 Euros. If the game looks cheap, in practice it can cause you many headaches and may even jeopardize the good deal that seemed to have done. It is clear that this situation will always be associated with the type of use that makes your PC.

What should you take into account

Before too is necessary to choose the screen size. This size is indicated in inches, and the measurement is made diagonally across the monitor. This field must take into account the information provided. Many times the indicated area also includes the frame, which usually involves the monitor. The move lower in the market is 15, "however, is the common size of 17", however, if you can invest, monitor 19 "or 21" will not be too much, although the latter suffers a price increase heavy.

When you have taken the decision on the size of the screen you want, it is imperative to consult the technical specifications of the monitor, there will be described as the main monitor, as it were of an ID.

GLOSSARY

1. Viewing Angle - angle from which you can view the monitor image.
2. Connection can be DVI (Digital) or DB-15 (Analog)
3. CRT - Cathode Ray Tube, or Cathode Ray Tube
4. Dot-Pitch is the spacing between the pixels of the monitor. The smaller the space, the better the image quality
5. Light is no more than the clarity and brightness. Measured in nit, 1 1 Nit = cd/m2, so the bigger, clearer and brighter the image
6. TFT - Thin Film Transistor, the new Active Matrix LCDs

Of the several characteristics that should be aware (not necessarily in that order), is the Dot Pitch. The lower the displayed value, the better. The most frequent value is 0.296 mm, see box.

Another important factor is the brightness, which indicates precisely the light intensity on the screen. The value is indicated on a number "cd/m2" and in this case, the higher the value, the better.

Then you can check the Contrast Ratio which measures the intensity between whites and blacks. Also here you can see large intervals between multiple monitors, 350:1, 400:1, 500:1, etc.. and the higher the number, the monitor will have greater contrast and thus a better image.

There have also attention to the Refresh Rate, which indicates how quickly the "sweep" the screen vertically, ie the number of times per second that the screen may show an image across the display and is available to show a new image. This value is displayed in Hz Typically, a rate of 75 Hz is sufficient.

Last but not least is the Response Time. The most common are monitors with 25 ms, however, the smaller this value, the better. If the use that will give the monitor is just a word processor, see the Internet and a little more, 25ms should be enough, but if their use is already to see more videos, games and other applications where there are fast movements, the ideal would be a monitor with a response time of 12 ms, thus avoiding the effect of "ghost" image (there are already displays on the market with a value of 8 ms).

Other Aspects

Basically, the above questions are the essential requirements that must take into account but, despite this fact may also bear in mind other aspects also depend on the type of use that is given to the monitor.

- Links

Many of the TFT has an entry "D-Sub", ie 15 pins, equivalent to the cables of conventional monitors (CRT), instead of having a DVI (digital). This means that there is a reduction of image quality, albeit slight.

In fact, the computer sends a digital image (if the graphics card support, should also take into account this factor) that is converted to analog (due to input of the monitor) and then converted into digital image.

If the monitor already has a DVI graphics card and support that format, the image is always digital, there will be no conversion and consequent loss of quality.

- Colour

Should then observe the number of colors that your monitor supports. The best monitors have 16.7 million true colors, while other monitors indicate 16.2 million, they actually only support 262 000 true color, or "recreate" artificially 16.2 million colors.

WARNING Some monitors, even new pixels may present "dead." The reasons for this fact may be different, however, it is possible that they exist. Some brands have established rules regarding the guarantee in such cases, inclusive, there are already some brands to ensure "0 Dead Pixels" as though the match could not detect any error of this nature, the opposite might happen, so when the purchase of a monitor, ask the shop where conditions could complain.

CONCLUSION

Given these specifications, the question what kind of use will have to buy the monitor, so you can evaluate what works best for your case and can therefore make an assessment of value for money according to the technical issues of this article because these are specifications that largely influence the prices of these monitors.

Below is a table which is not binding, aims only to place the type of use in technical characteristics which should take into account, however, you should always consult a qualified technician in order to more accurately evaluate your case.

Contrast> 250:1> 500:1> 600:1
Brightness> 250 cd/m2> 300cd/m2> 300 cd/m2
Response Rate 25 ms 12 ms 12 ms / 8 ms
16.2 Million Colors 16.7 M 16.7 M