Things You Should Look For When Buying a Monitor
How CRT Works
TFT LCD's Active Matrix
If you are thinking about replacing your current computer monitor with a newer one, there are some things that you will have to look for. Replacing a monitor is not as easy as it may sound. If you are not sure what you need to look for and then end up buying a monitor that does not really suit your needs, you will be pretty upset having spent your money for a display device that you may not have even wanted at all in the first place. A monitor has a lot of important elements that you should never ignore if you want to get the one that will satisfy you and the one you can proudly show off to your friends and colleagues. These elements often include the kinds of applications you use the most, the room capacity reserved on your computer desk for the monitor, the amount of spaces you may need for your virtual desktop, the maximum amount of money you are willing to spend on the monitor and some other things. So, pay attention to everything we will tell you next.
Will You Go for CRT or LCD?
Most computer users will probably say that they will prefer an LCD monitor to a CRT one. However, before you make up your mind on which to choose, you had better have some ideas on how the CRT and the LCD monitors work.
It is true that LCD (Liquid Crystal Display) monitors are easier to find than the CRT (Cathode Ray Tube) ones these days. However, history has shown that the skillful professionals in the world of computer graphics would normally go for the CRT monitors. Needless to say, there were reasons for this. Compared to their LCD counterparts, CRT monitors were always built to support wider resolution ranges, greater color nuance and truer colors. Nonetheless, back in the year 2005, computer monitor manufacturers started to end the production of their CRT monitors, including the aperture-grille type. For your information, this type was the most sought after when it came to professional photography and graphical works.
But things have changed. Today, professionals tend to prefer high end LCD monitors that feature colors almost as perfect as CRTs did in the past. The professionals also prefer LCD monitors because they require less power. In addition to that, there are now quite a lot of software and hardware designed to calibrate the colors of LCD screens even more making them even better for use by the professionals. To enhance LCD displays even further, today’s manufacturers also take advantage of a wider color gamut, LED backlighting and continuous black level improvements. Yet, for even better LCD displays, you can get TFT – which stands for Thin Film Transistor – monitors which we will discuss later.
Before you are determined of which to choose between these 2 types of monitors, it may help to see how each of them works.
CRT monitors have a phosphorus film at which they fire charged electrons using an electron gun – also known as cathode thus the name Cathode Ray Tube. When the electrons make contact with the film, light is created and this is what our eyes actually see.
The cathode triggers a ray which is a stream of multiple electrons. There are also some deflection plates in place to direct the electron stream towards the phosphorus film. Yet, to make sure that the stream hits where it is supposed to, manufacturers wind copper wire to create a magnetic field with certain strengths.
It is also important to note that there are always 2 sets of wires located within a CRT monitor. One set is meant to deflect the electron stream mentioned earlier in a vertical direction while the other is meant to deflect it horizontally. Being deflected at a high speed, the stream lights up every pixel you can see on the monitor screen.
However, the stream will give out no more than a black and white image. In order for a CRT monitor to be capable of providing colorful images, it will require 3 other streams of electrons which are the red, green and blue – more popular as RGB – electron streams. Three phosphorus films – also in red, green and blue – are necessary as well. The films will need to be laid out in stretches of each of the colors and, when necessary, a single color will have to aim at its own film. This way, all the 3 colors will be right behind each of the pixels on the screen and the mixture that comes from the colored glows originating from the films will create the colors your eyes see on a CRT monitor.
The main difference between a CRT and an LCD monitor is their method of lighting up the monitor screen. While CRT uses phosphorus films to produce light, LCD does not really produce light. Instead, LCD blocks and unblocks the light using the liquid crystals it has. The liquid crystals of LCD monitors come in the form of a liquid and a crystalline (solid) state.
Using electric current, LCD monitors work by twisting and untwisting the liquid crystals in such a way so that only the required lights are capable of passing through them and other lights are blocked.
You also need to know that there are 2 types of LCD screens you can avail. These are the ones that come with active matrix and the ones that feature passive matrix. The first generation LCD display devices usually come with the passive matrix. They work by setting up a grid containing thousands of transistors along with liquid crystals. Then, a charge will be delivered to each of the pixels for the desired effects. However, there are some problems. These first generation LCDs tend to have some ghosting patterns due to the slow response time. In addition to that, slight blurring effects often appear as well due to the subsequent liquid crystals being partially charged.
The next generation LCD which is TFT, on the other hand, is far better. As a matter of fact, TFT is the best type of LCD you can avail to date. A TFT screen uses an active matrix that features a capacitor besides a transistor behind each pixel. With this capacitor, a TFT screen is capable of holding the proper charge until it acquires the next refresh. In addition to that, it makes sure that the charge will be sent only to the proper pixels resulting in better images you can see on the monitor screen. Thanks to this proper charge combined with gradually increasing voltage of each of the liquid crystals they have, today’s LCDs are mostly capable of giving out 256-greyscale.
Yet, for the TFT monitors to be able to give out colorful images on the screen, they must be equipped with 3 sub-pixels behind each of the pixels they have. Just like CRT, these 3 sub-pixels will need to be in the colors of RGB. This way, the TFT monitors will be able to produce 256 shades of each of the RGB colors. As a result, about 16.8 million colors are obtained that come from 256x256x256 of the RGB colors.
Every monitor has its own resolution. This resolution determines how many colored pixels a monitor will be able to display on its screen. With that being said, it is of utmost importance to check out the native resolution of a monitor you are about to buy. The native resolution is the resolution with which images will look best on the monitor screen. Although it is true that you can adjust the resolution to be higher or lower depending on your preference, the images on the screen may appear noisy.
If you use Windows Vista, the vector graphics that the OS uses may help overcome this problem a little. Yet, still, it is the native – that is also the maximum – resolution that will give you the sharpest images possible. Also bear in mind that different models handle non-native resolution differently so you may want to consider looking at quite a few models before making your decision.
Most of the time, monitors measuring 17 up to 19 inches diagonally have a native resolution of 1280x1024 pixels. Widescreen monitors that come in 23 or 24 inches, in comparison, mostly feature 1920x1200 pixels as their native resolution. Thirty-inch widescreen monitors, on the other hand, mostly support a native resolution of up to 2560x1600 pixels.
In some cases, you may want to use a resolution that is lower than native. For example, this may help you see some very small objects on the screen more clearly. However, the images will often turn out less defined as it is only part of the pixels that your monitor uses to scale up the screen images. Additionally, you cannot adjust a monitor’s resolution to exceed its native resolution. That said, it is impossible to get a resolution of 1920x1200 pixels on a monitor with a native resolution of 1280x1024 pixels.
These days, you may find a lot of options when it comes to native resolution. Therefore, you need to choose a monitor with a native resolution that works best for most, if not all, of the applications you use day in day out.
Basically, dot pitch represents how many spaces exist among the screen pixels. In the case of a CRT monitor, dot pitch represents how far each hole is located from another in the steel grill or shadow mask. For LCD, on the other hand, this term is used to indicate how far same colored pixels are located among one another on the screen.
It is the dot pitch that determines the quality of images a monitor can produce. The closer the dots are to one another, the sharper the quality of the images produced. If the dots are too far from one another, images will appear grainy and this can prove to be pretty disturbing especially when you are playing games.
Dot pitches commonly range from .25mm up to .31mm. Remember that it is always best to look for a monitor with smaller dot pitch as they support more pixels resulting in higher native resolution.
The refresh rate of a monitor tells you the total number of times a monitor can be refreshed every second. For an example, if your monitor has a refresh rate of 75Hz (Hertz), it can be refreshed up to 75 times every second. In this case, you will most likely prefer faster refresh rate otherwise you may notice your monitor flickering either slightly or drastically. Besides pretty annoying, this often results in eye strains as well as headaches.
However, how fast or slow the refresh rate of your monitor is, it is determined by the maximum resolution you set on the monitor itself. Higher resolutions always have more pixels the monitor needs to scan and it may take a while to accomplish a full screen pass. As a result, the maximum refresh rate will be lowered.
Non-widescreen monitors usually come with an aspect ratio of 4:3. Widescreen monitors, on the other hand, used to come with an aspect ratio of 16:10. However, for the past few years, manufacturers have started producing widescreen monitors with the aspect ratio of 16:9 just like what you can usually see on HDTVs.
Widescreen monitors are particularly efficient if you need to work on large spreadsheets or if you need to use such a program as Adobe Photoshop that features quite a lot of palettes and toolbars. It is also quite convenient to view documents next to each other on a widescreen monitor. For example, having a 24-inch widescreen monitor, you will be able to browse the web quite conveniently using 2 web browsers side by side. Additionally, watching DVDs on a widescreen monitor can also offer you quite a comfort even though the quality of the images produced may not be as good as that of a TV set.
Physical and Viewable Size
It is true that most of us may prefer larger monitors. However, it is of utmost importance to consider the space you have for your monitor. Also, keep in mind that a widescreen monitor’s viewable size is in fact always smaller than that of a non-widescreen monitor. With that being said, if you have a widescreen monitor measuring 21 inches diagonally, the viewable size of your monitor is in fact the same as that of a non-widescreen monitor measuring 19 inches diagonally.
Viewing angle represents the maximum distance you can set your monitor aside, below or above the center until the quality of the screen images deteriorates unacceptably. This viewing angle is normally measured in degrees and is very important for achieving consistent and accurate colors which are crucial for digital photo editing.
There are no standards for a monitor’s viewing angle. Therefore, you will have to estimate a monitor’s viewing angle by yourself. However, in most cases, a monitor tends to have a minimum viewing angle of 160 degrees. So, if you happen to find one with a maximum viewing angle of 150 degrees, you had better turn away to other monitors.
This indicates how light intensity differs between the darkest black and the brightest white of an LCD. It is best to go for an LCD with a contrast ratio of at least 400:1. A lower contrast ratio than 400:1 tends to wash out colors when the brightness is increased and make colors disappear at the time the brightness is decreased.
However, this does not necessarily mean you are better off buying a monitor with a very high contrast ratio. You need to keep in mind that it is only better up to a certain point. Besides, monitor manufacturers normally use “fuzzy math” to estimate the contrast ratio of their display devices. As a result, it may not be accurate all the time.
Brightness is measured in either nits or candelas per square meter (cd/m2). It is used to indicate the amount of light originating from a monitor screen giving out pure white color. You will mostly find monitors with a brightness level measuring 250 cd/m2. This level often turns out to be more than enough.
When you plan to buy a new monitor, don’t be tempted by the brightness you see on the monitor displayed in the stores. It is often the case that these monitors are set to display their maximum brightness to catch your attention. For graphics and video, it is true that high brightness can be very eye catching. Unfortunately, it can be tiring for your eyes over time. It can even be worse for viewing texts on the screen. Additionally, high brightness also washes out photographic nuances. This is why all monitors come with the option of adjusting their brightness level.
Most of today’s monitors already support up to 24-bit color depth. This means that most of the monitors you can avail these days are capable of producing up to 16.77 million colors. Of course, even with today’s monitors, you can still switch to older color depths such as 65,000 colors, 256 colors and 16 colors. Yet, 24-bit color depth is the true color and will thus give you the best image quality.
This is the time that a pixel requires in order to change and is measured in milliseconds. It is best for you to go for a monitor with as fast a response time as possible. This way, you are unlikely to notice glitches on the images you see on your monitor screen.
Response time is comprised of rise-and-fall and gray-to-gray response time. Rise-and-fall response time indicates how long a pixel takes to change from black to white – known as rise – and then back to black again – known as fall. Gray-to-gray response time, on the other hand, indicates how long a pixel takes to turn from one particular gray shade to another.
Digital vs. Analog
There are 2 main technologies you can find these days. These are the long lasting VGA technology and the new DVI technology. VGA – which stands for Video Graphics Adapter – works by converting a digital signal into analogue so that CRT monitors will understand it. However, VGA is the older analogue standard that may not work with every modern LCD today. This is when the DVI technology comes in pretty handy.
DVI – which stands for Digital Visual Interface – does not need to convert the digital signal to analogue at all. DVI simply keeps the digital signal as what it is. This way, the signal will not suffer from any degradation or loss of quality assuring you get the best image quality possible.
In case you have a video card that supports a DVI output, it is highly recommended that you buy a monitor that is compatible with the DVI technology so that you get the best signal and image quality.
Some of today’s modern LCDs have special inputs on them. These special inputs often consist of memory card slots and S-Video ports – both of which are often sought after by videographers and photographers alike, composite and/or component inputs – for DVD lovers – and also HDMI ports that are perfect for playing Blu-ray discs or video games.
Try It in Advance
Even though you may feel interested in a particular monitor model you come across while browsing the internet, you had better not buy a monitor online. Instead, you had better visit the nearest local stores. Going to the local stores will enable you to test the monitor model of your preference. This way, you will be able to tell whether or not the monitor really suits you.
Are You a Big Music Fan?
In that case, you may want to consider buying a monitor that features built-in speakers. It is not so hard to find such a monitor model these days. Besides the speakers can usually provide quite good quality sound, monitors with built-in speakers also help you save your desktop space. Some vendors offer to mount the speakers on the sides of the monitors while others offer to feature soundbars.
Got Your Monitor? Now, What Do You Do with the Old One?
First and foremost, do not dump your old monitor to the thrash but recycle it instead. This way, you will do your environment a good deed. In addition to that, never forget that some states – probably including where you are living in – prohibit dumping monitors to the municipal landfills. This is because LCDs normally have lead and mercury in them. CRTs, in comparison, usually have 4 up to 6 pounds of lead as well as other toxic materials in them. All these toxic materials are capable of leaching into water and soil in no time at all so they need to be disposed of properly to keep everyone and everything safe.
However, if your old monitor is still in pretty good shape, it is wiser for you to hand it over to someone else who may need it. To do this, you can have a look at your local charity listings accepting computer equipments. You can also trade in your old monitor in Craigslist if you want to. But remember that all these are possible only if your old monitor is still working. Otherwise, you will have to find the recycling spot in your area to get it recycled.
© 2011 Richie Setiawan. All rights reserved worldwide.
Digital vs. Analogue
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