Monitors
(Often Called Displays or Screens)
When you have only two pennies left in the world,
buy a loaf of bread with one, and a lily with the other.
Chinese Proverb
Intro
There are two things you must not scrimp on for your computer: the amount of RAM and the quality of the display. In the case of the latter, your eyes, your work and your aesthetic sensibilities will reward you.
This subject could rate a publication of its own. You need to:
- view the screen in action before buying if you can;
- or at least read reviews on the Internet (more about this in Searching);
- or ask someone to do that for you.
- or all of the above.
The key areas are refresh rate (for CRTs), pixel size, and colour quality.
Refresh Rate
CRT screens aren't common on new PCs now, but if you acquire one for some reason you need to know about refresh rate.
If a CRT display renews the screen too slowly (like the old silent movies), there will be noticeable flicker in the (cathode ray tube) screen. Even if the flicker isn’t readily detectable you can be unconsciously affected, resulting in fatigue and tired eyes. You need a refresh rate of at least 75Hz (Hz = cycles per second), 85Hz to be certain. If you have a graphics card this will be easily attained.
Flicker is detected more easily in peripheral vision. So even if you don't see it, the person at the next desk may be distracted by it. Check by focussing your eyes off to one side of your monitor so that you can see the screen out of the corner of your eye.
Don't force the screen to a higher refresh rate than it is designed for. Some folk are more sensitive to this than others, but few will detect flicker at 85Hz, so any higher is usually unnecessary.
LCD (liquid crystal display) screens don’t noticeably flicker and are usually set to 60Hz.
Pixel Size
Just as newspaper pictures were once composed of round dots, the displayed image is composed of many small picture elements or pixels. Just like the old newspaper, the smaller they are, the better the picture.
LCD Monitors
These are much less bulky and obtrusive than CRTs. Until recently they were also quite a bit dearer and the contrast and colour richness were not usually as good. This technology has improved and as a result CRT monitors are on the way out.
LCDs use about 70% less power than CRTs of equivalent size.
A 17" LCD screen has almost the same viewing area as a 19" CRT screen. With a 17" LCD display you want a screen resolution of at least 1024 × 768 pixels. A pixel on a screen is the rectangular equivalent of a newspaper picture dot.
I recommend that you go for a 22" screen if your budget isn't too tight. It should display 1680 x 1050 px. I have a 24" Dell 2407 (1920 x 1200 px) and I love it, but 22" is adequate for most people's needs.
Poorer quality LCD monitors, which often accompany bargain PCs, usually betray themselves with poor display of text. Black text on a white document should be sharp — no blurring.
If you're buying a complete PC, ask the retailer to ensure that Clear Type is being used by Windows to smooth screen fonts. If they don't know how to do this, go somewhere else to spend your hard-earned cash.
There are several things to take into account:
- Response time. 8ms or less.
- Native resolution. There's not much point in paying
extra for a 19"
monitor if it has the same resolution as a 17" (usually 1280 x 1024).
You just need to sit further away. Unlike CRTs, most LCDs only display one resolution properly.
If you go for 19" you want 1440 x 900; 22" 1680x1050; 24" 1920 x 1200. - Screen size. Unless you're on a tight budget I wouldn't
settle for
less than 22" at today's prices. - Aspect ratio. Wide screen 16:9 or standard 4:3. Anything
over 19"
will probably be 16:9. - Contrast. No less than 700:1.
- Brightness. No less than 280 cd/m2.
- Screen reflection. Highly reflective screens are alleged to give a crisper picture than matt finish screens. That may be so, but if you're in an environment where reflection of bright lights and windows is likely to be a problem you need to take this into account.
Unlike CRTs, with LCDs refresh rate is not an issue. Most are fixed at 60Hz.
Dell, Samsung, HP, Philips, La Cie, Sony and Viewsonic are good brands.
If it's practicable see the screen in action at a retailer and in suitable lighting. Otherwise search for reviews on the monitor you're considering. Google is your friend. PC Magazine and CNet do very good reviews.
Some monitors have screens which may be swivelled 90º to give a portrait view. Windows automatically adjusts the view to suit. Great for people who wish to see full-sized A3 documents in portrait mode.
Maximum screen size
Many people find that 24" is the largest practical size for a desktop screen. If it's any bigger you need to scan from side to side to an uncomfortable degree.
CRT Flat Screen Monitors
CRT
displays are big and bulky, but they have good colour and contrast - and
they're relatively cheap.
Don’t for one moment consider a CRT monitor that doesn’t have a true flat screen. Otherwise you’ll be plagued with reflection problems from lights, doors and windows.
You can purchase an excellent 17" CRT flat screen monitor, adequate for most people’s purposes very cheaply. A dot pitch of 0.25mm should give good resolution. A 17" screen is adequate, 19" is better.
But! Having said that...
If you're going to be doing professional computer graphics work, including photo editing, and you want top results when your output is printed, then you need to do extra homework on monitors. I believe that good LCD monitors are now up to the task but some graphics professionals still swear by CRTs. If you share this view:
- You will need a 19" or 21" CRT display of top quality. It will weigh a ton, and it will be every bit as expensive as the equivalent LCD.
- You will need a graphics card of good quality and with at least 256MB of video graphics memory.
- LCD displays are OK for creating and editing graphics intended for use on the Internet. Most viewers of your work will be looking at the result on LCD screens.
And What's More...
This matter is subject to constant change (like everything else in computing) you can buy an LCD monitor with equivalent picture quality to a top CRT, but the colour ranges for the two types are different.
Screen Burn-In, It's History!
Now and then you'll hear about the dreaded "screen burn in". In the bad old days of DOS, green or amber screen monitors displayed only text, and it was in fixed position lines. Eventually permanent lines were burnt into the phosphor on the inside of the screen.
Modern monitors don't have this problem to any noticeable degree: firstly, they're less susceptible and secondly, they're displaying continually changing vistas over the whole screen. LCD screens don't have permanent burn in at all and CRT screens barely.
Nevertheless, your screen, like your TV and yourself, has a limited lifetime. Colours will fade eventually. It's probably in tens of 1000s of hours, but save power, prolong its life and do the planet a favour by setting it up to switch off after a few minutes of inactivity. See how to do that here: Display Properties.
Your fancy screensaver is consuming valuable power unnecessarily, have your display switch to sleep mode instead.
Do the planet a favour – think finite resources, exponential demand.
