Tag Archives: vision problems

Computer Entry: How to Buy a Computer Monitor

This article is part of my Computer series, click here for the list of other entries.

When it comes to monitors there are many things to consider. I will tell you more than you probably ever wanted to know, at the end of this you will be a monitor expert and know more than almost any clerk at any store you walk in to. It may be a bit long with stick with it, you will be glad you did.

First we will start with the difference between a CRT and a LCD. By now the LCD has won the game for new monitors, but many still debate whether to keep the OLD CRT or to upgrade to the LCD. Well there are many reasons that a LCD is better, the only reason to use a CRT is if you don’t have the money to get a LCD.

But even with that it will still cost you. The average 19” LCD uses only about 50W of power, while the average 19” CRT is over 250W. In Arizona we have cheap power, costing only on average 9 cents per KWH. After taxes and such it is about 12 cents. If you count the heat created by the CRT and the power to cool this heat during the summer you would have to count about 24 cents per KWH during the summer and 12 cents during the winter. This is an average of 18 cents per KWH. A 200 usage will result in 3.6 cents per hour. I use my monitor about 10 hours a day, 7 days a week. That is $2.50 per week. With an average 19” monitor costing less than $170 it would only take 68 weeks for a new 19” LCD to pay for itself. If this is not reason enough to get one then let me give you a few more.

The LCD monitor will take up much less space on your desk.
The LCD monitor will allow you to work longer with less eye strain. Think of a CRT monitor as a particle accelerator aimed at your head.
The LCD monitor has a much crisper picture.
The LCD monitor is much less heavy in case you need to move it.

So now that you see clearly that a LCD is the best choice PLEASE don’t do what most of my customers want to do, they simply select a size and shop for the absolute cheapest LCD of that size. That is a very bad idea. Like anything else you get what you pay for, and in monitors if you pay a bit more you really get a lot extra. Well there are a lot of things to look for.

LCD monitors work by having a white light in the background, then each pixel blocks anywhere from no light to all of the light, it does it in Red, Green and in Blue. So to make purple it will only block the green, red and blue shine through and purple is created. Most LCD monitors can block each color in any of 256 different levels. This gives each pixel 16.8 million different color combos.

Monitors also have different speeds at which they can change these colors. Most are 5ms, meaning 5/100th of a second, or 20 times per second. Most humans can only see about 20-25 updates per second, the older you are the lower this number is. For anything except video or games 5ms is fine, but if you want to have faster refresh rates 2ms is a much better for only a little more money. The eyes of most people can not tell the difference between 2ms and 5ms so don’t get all caught up in this. Beware that some cheap monitors are 8 or even 10ms, this costs them less to make and many unaware customers looking only at price buy these, even people with bad eyes can notice video slowness in these monitors.

As I said there is a white light at the back, if you want great bright graphics you need this light to be brighter. They measure this brightness in cd/m2 which means Candle power per square meter. A rating of 250 cd/m2 would be like having 250 candles in a square meter. For me the higher this rating is the better. If you are in a bright room such as an office you really need to focus on this feature. Again many cheap monitors are in the 200-250 range, simple because it is cheaper and people often only look at price. 300 is actually much nicer and the most popular brightness level, but for a bit more money you can find 400 and 500 cd/m2 models.

Now because your pixels are blocking the light you have to be concerned of how good of a job they are doing. This is called Contrast Ration. 500:1 means that the whitest white is 500 times brighter than the darkest dark. We already know exactly how bright the white is by the brightness measurement so what we really are talking about is how dark the monitor can get. Dark is great for video games, and movies. If you are in a typical office environment just doing normal typical office stuff then forget this number, it means very little to you. But if you want great crisp colors and dark darks in you movie then look for a large ratio. 700:1 and 800: are good and very common, only the cheapest or oldest monitors will have numbers lower than this. 1000:1 is the most common, but 3000:1 is getting very popular among high end quality monitors.

Now you have to decide if you want speakers or not, I have a great set of speakers so I don’t care either way, but for most offices your computer probably does not have speakers. About half of these monitors have at least basic speakers. Because I don’t need them I will look for one without them or one that has them hidden. If you need them you may want to look at the different sound out put but I have found that almost all of them are a very poor 1 to 2 Watts of power.

Now you will see monitors that are grey, or black or silver, even white. For me a black border is by far the best. It is much less distracting to the eyes.

You also need to decide if you want the Widescreen 16:9 ratio or the normal 4:3 ratio. Because the size of the screen is measured diagonally a monitor of the same diagonal size that is 4:3 will be about 10% larger than a widescreen. But if you are watching a movie and 40% of your screen is the black bars on the top and bottom then your movie will be larger on a 16:9. For me I like to have wide screen monitors, because I can then put things side by side. It is better for writing things surfing the web. Humans see much wider than they see high, so it makes sense.

Now you also have the choice of inputs with most nicer LCD monitors. The cheapest ones only have VGA (15-Din), but the nicer ones also offer DVI and recently HDMI. Some even have component input. If your monitor has more than 1 then you usually have a button that lets you select which input you would like to use at any given time, this is useful for the people with more computers than monitors, like techs often are. DVI is digital and if your computer has a DVI out I would look for a DVI monitor for sure, it is much nicer, but if you computer only has VGA then only get DVI if it is free or you are fairly sure you are upgrading soon.

I saved the two most important considerations for last, Size and Resolution. Most people think too much about money and they instantly think that smaller is better, but in todays market a 15” and a 17” screen are the same price, and in many cases the 15” is more money. Also a 19” is often only $20 more than a 17” and a 22” is often only $40 more than the 19”. For most people I suggest a 19” for offices and a 22” for home use. If you use the computer a lot at the office then get the 22”. See you are already paying for the monitor, and if you want to upgrade at a time in the future you will not be able to get the full value for your smaller one, thus it will cost much more to upgrade later than it will to do so today, so buy the size you really want right now.

Next is resolution, this comes back to the eyes question. Most sizes have a resolution that makes up about 90% of the market for that size. Almost all 19” widescreen monitors are 1440×900 while most 22” monitors are 1680×1050. Every now and then you can find monitors for about 20-30% more money that jump to the next level, such as a 1680×1050 for a 19” Monitor. Most monitors are designed for what looks good at that size. I would only suggest someone to go to the higher resolution if they have very good way above average eyesight.

You should always try to run a LCD at the highest resolution that it can support, if you don’t then your images will look very bad. It works like this. If the monitor can display 1280 pixels wide but you select 1024 then that means that 5 pixels in the monitor are trying to display every 4. So they will not line up, it works like this. Imagine pixel 1,2,3,4,5 and data pixels a,b,c,d. Pixel 1 will show the color of a and 25% the color of b. Pixel 2 will show 75% the color of b and 50% the color c. Pixel 3 will be the average of half the color of b and half of c. This is easy math for your computer and monitor but it will make everything look blended and blurry. For all the people who can not see well lowering your resolution will make your screen look even worse than running at the correct resolution and resizing as much as you can to make things larger.

One of the first things that I tell people is to think about their eyes. How large do they like text. Computers today STILL mostly render things based upon resolution. In a dream world you should always run your monitor at the highest resolution, so things would be the most smooth but be able to resize things based upon your taste BUT this is NOT the case. Unfortunately MANY things in computers are still a set number of pixels in size. At least in vista they allow you to change most of your OS to make it larger, you really only have this problem on the web. So if a person with bad vision buys a really large 24” monitor and has a resolution of 1920×1200 and they use that resolution things will still be small, so they sent the resolution to something like 1280×768, now things are only about half as crisp and clear as they should be, there is no winning this game. They could always use the zoom feature of their OS but that is not very user friendly. I hope they fix this problem but I don’t see this ever being fixed.

Last, monitors die sometimes, also they often have dead pixels, a pixels that will not change to the correct color all of the time. Most of these are covered under warranty, but many companies will not return a monitor unless it has at least 6 or 8 dead pixels. You want to be clear of this before you buy. And if you are buying a really cheap monitor then test it before you leave the store. Almost every year a new company starts up and dumps a ton of cheap monitors on the market, they sell millions of units promising a 3 or even 5 year warranty, then after a year they go out of business, change the name on all the boxes and do it all over again. Now there are some really good quality monitors from companies you may never have heard of, just because you have not heard of them does not mean that they are not good, but if an expert has not heard of them beware. We currently sell Hanns-G for many of our mid range monitors and we sell Samsung or Viewsonic for our high end monitors. We have had great experiences with all three of these. We have had bad luck with KDS, Acer and a few other brands that are now gone.

So bottom line, think about what your needs are. Don’t shop for the cheapest. If you have more questions then contact me, I will be happy to help you select your monitor, and I will probably be able to find a much better one at a better price than you ever thought.

This ended up being much longer than I thought, thanks for reading all of it, please forward this to anyone you know who is thinking of getting a new monitor, they will be happy you did. Leave a comment if you liked this blog.