By Jason Romney and Edward Jozis
A computer screen's clarity and size is the most conspicuous aspect of a system. Over coming weeks, we'll show you what to look for in a good monitor - and spotlight the danger areas.
A jealous home computer user may quickly notice that friends seem to have a much better looking screen display than the standard package deal job: a 14 inch monitor with VGA resolution.
Why is this so? The first thing you notice about monitors is size. If you measure the picture tube of your new monitor, you may be in for a surprise.
With the average Taiwanese monitor, even though the monitor's picture tube is 14 inches (and this means the diagonal measure from left bottom corner to top right corner, not simply from top to bottom), the actual picture size will be considerably less.
A half inch border around the picture area (with no way of adjusting it) is common.
More expensive flat screen picture tubes do not waste screen space. For example, a 17 inch monitor provides 19 percent more active display area.
There is also less distortion at the edges - especially important in Windows environments.
Most vendors claim to be selling a 15 inch monitor, but your measurement will show only 13.5 inches. Promoting that 13.5 inch monitor as a 15 inch is justified, they claim, because a flat screen monitor (with a picture reaching right out to the screen edge) yields the same EFFECTIVE viewing area of a normal 15 inch monitor.
This sounds dodgy, but is relatively standard practice.
With a $450 Taiwanese monitor, a large border around the effective viewing area is reasonable. But when paying $800 or more for a good quality 15 inch or larger flat screen monitor, you should really expect something better such as controls to stretch the picture right out to the screen edges.
Another important issue is screen resolution. This is controlled by the hardware design of your VGA card in conjunction with appropriate software drivers, but your monitor must have the hardware ability to display the driver software-determined resolution of your choice.
Most monitors can display standard VGA with 640x480 pixel resolution. However, better resolutions such as 800x600 and 1024x768 pixels make an enormous difference to the appearance of your work. (Apple's new monitors - a 17 and 21 inch model - are capable of video resolution up to 1152x870 at 75Hz.)
If you install the mysterious disks that come with your VGA plug-in card you can often make Microsoft Windows run in one of these higher resolutions.
In actuality, this merely makes your icons and menus smaller. The idea of the higher resolution is not to give you more dots on the same size characters to make them smoother, but rather to make the characters smaller, each still having the same number of dots.
The picture is then expanded by virtue of the physical size of your monitor screen, the aim being to have more icons and text visible, effectively making a bigger desktop.
Next week: specific recommendations about the right screen resolution for your monitor size.
Footnote:
High quality monitors such as the Matsushita or more expensive NEC range, usually come with a cable for a PC. However, they can operate with a Macintosh.
An inexpensive adapter plug can be purchased which converts a PC cable designed for a VGA card, for Macintosh use.
For enquiries: 699 8844.
Monitors Part 2
By Jason Romney and Edward Jozis
When buying a new monitor for your computer, never be seduced by size alone. Last week we explained how a monitor capable of displaying high resolutions can make more icons and text visible, effectively making a bigger desktop.
But this is actually done by making the icons and characters smaller. That is why on 14 inch monitors (even of good quality), the bearable upper resolution limit is usually 800x600 resolution.
With 1024x768, even if your 14 inch monitor can do it, the icons get too small and mouse movements become a challenge of careful aiming and eyestrain.
Thus with 1024x768 resolution you really need a 15 inch or larger monitor. Some VGA cards and monitors extend to 1280x1024 resolution - but again, you really need no less than a 17 inch screen for such modes.
It is important to realise, however, that some software will only run properly in 640x480 mode because that is the traditional IBM VGA standard. Some higher resolutions, such as 800x600 mode, are not IBM standard.
This is particularly so for multi-media games and so forth, which may well throw up a message raising incompatibility and other problems if you have a non-standard, that is, non-VGA screen resolution.
Another important consideration is something called interlacing. Your salesperson will always boast about a monitor being ``non-interlaced'' (if it is).
Be careful if this is NOT mentioned because a monitor with interlaced scanning will display noticeable flicker, especially on horizontal lines.
Monitors are usually non-interlaced for 640x480 and 800x600 modes, but for 1024x768 or greater, non-interlacing adds to the cost and may not be available - always ask because non-interlacing at higher resolution, which avoids screen jitter, is well worth the extra money.
It is worth remembering that even if you suspect your VGA card does not support non-interlaced operation, you should check the mysterious little switches at the end of the card and read the fine print in the manual - rejigging such switches may make it non-interlaced.
Another important monitor issue is ``scan rate" which refers to how quickly the dot scans from the top corner to the bottom corner of the picture tube - 60Hz means 60 times per second, 50Hz means 50 times per second, and so on.
A high scan rate reduces flicker - it is important to realise that not all monitors lock into their highest scan rate automatically and, even if non-interlaced, you can sometimes still notice flicker on very large screens if the highest scan rate is not engaged.
This is usually controlled by hardware settings (on your VGA card) and really requires investigation of your unique system setup. On the common Paradise card, for example, there are dip switches that allow the card to be set from 56Hz to 72Hz (this is called `monitor vertical retrace timing' in the manual).
If you experiment with scan rates, be careful. Not all monitors will accommodate the full range of scan rates. If you choose a scan rate your monitor can't support, your expensive investment may well be damaged.
Monitors Part 3
By Jason Romney
If the word ``multi-media" leaves you blank, just think of your computer as the celebrant of a marriage between pictures, sound and video.
Actually, it's been a bit of a shotgun wedding.
That's why when you buy one of the attractive looking computer package deals available nowadays, you need to be careful that your powerful new computer isn't actually a Frankenstein's monster - full of ill-fitting components and jagged around the edges.
A computer's screen is a very important part of its ability to present multi-media products. But no less important is the video card you slot into your computer and into which your monitor plugs.
Make sure your video card has a so-called ``feature connector" on its top edge - cheap video cards often do not have one. This mysterious little connector is not visible from the rear of the computer, only when you open the computer up.
Why do you need one? A video converter card (which you may buy in addition to your VGA card and plug into a nearby slot) enables you to feed images into and out of your PC from other video sources eg a camera or video recorder.
Many of the popular video converter cards need to plug into the ``feature connector" on your VGA card via a cable. Thus, if you don't have a ``feature connector" you are immediately kicked out of the multi-media marriage's reception party.
That's one of the biggest traps, but there are plenty more.
For example, you should know about ``degausing". This is a facility built into monitors which demagnetises the picture tube.
Degausing is important because if your monitor comes close to any magnetic field (for example, a loudspeaker), it can become ``magnetised" which causes color distortion.
Particularly with large monitors, even the earth's magnetic field can cause color distortion and impaired picture geometry - you only have to turn your monitor sideways or upside down while it is running to see how the colors change.
Some monitors may need to be switched off and cooled down for half an hour or so, before being switched on again after being moved into their new position.
This is because most monitors demagnetise the picture tube automatically upon startup. Some monitors also have a degausing button which will take care of the problem whenever necessary, without the need to switch the monitor off.
Another important thing to look for in a monitor is digital storage settings. When you change scan rates and resolution modes, an average Taiwanese monitor's picture size and position may well change also.
For example, the picture may be smaller and shifted to the left or right - even off the screen. Digital storage settings allow a good monitor such as an NEC or the less expensive but equal performance Matsushita, to have its screen characteristics changed from the front console and stored.
This ensures your monitor's picture is optimised no matter what resolution or scan rate you choose.
* Micronica is the authorised Australian distributor for Matsushita. For dealer and retail enquiries call Edward Jozis on 699 8844.
Monitors Part 4
By Jason Romney and Edward Jozis
In the final installment of our four-part series on computer monitors, Home Entertainment provides a checklist for monitor buyers.
A monitor can be an expensive investment. You will be stuck looking at whatever you finally buy for many years - and up close, too. So do a little homework now, before you buy, and save a lot of aggravation.
The most important rule is: NEVER buy a monitor without looking carefully at the actual monitor you will take home.
When you make that essential examination, one important check point is picture purity. For example, if you have the whole screen colored blue, is the color and also the intensity of the color, even across the screen.
If your picture purity is out you will notice (in the case of a blue screen), purple or even red and green blotches in the corners and on the sides. There may also be slightly dark patches on parts of the picture.
Even worse, you may notice some power supply noise or interference causing wavering or horizontal light and dark bands in the picture.
Also check for picture jitter in the vertical or horizontal direction. Ideally, you should not buy a monitor which isn't capable of rock solid picture stability.
Another important check point is whether the monitor has a non-glare picture tube. This is a slight frosting type of effect on the screen which reduces strong reflections of light from above and behind the viewer so it tends to defuse spots caused by, for example, light globes and fluorescent tubes.
With modern monitors, a silica coating with anti-electrostatic qualities is used so as not to attract dust as well.
Another checkpoint is dot pitch. Simply looking at the picture quality of the monitor is often the best guide, but if you tend to pore over brochures when you get home, check that the claimed dot pitch of your proposed purchase is 0.31mm or less.
Good quality monitors normally have a dot pitch of 0.28mm. By comparison, 0.39mm is close to consumer TV quality. With this dot pitch, the effect is that the picture will have a very fine chicken wire-type appearance on the screen.
Of course, it isn't all in the figures. You can find a 0.28mm dot pitch monitor with poor focus will look worse than a 0.31mm dot pitch monitor with sharp focus and good electronics - but dot pitch is generally a good pointer to know about.
Another checkpoint is so-called screen ``geometry"; is your picture nice and square? Check that the top edge of the actual picture area, in an application such as Microsoft Windows, is actually nice and horizontal (that is, not tilted).
And more particularly, check that the height of the picture on the left side is equal to the height on the right side of the picture.
So-called ``misconvergence" can be another problem. Convergence is the effect where white text seems to have a haze of color around it, usually blue or red. When present in computer monitors it is usually more pronounced at the extreme edges of the screen than the centre.
These are the key points. Of course, the components' quality (such as soldering and tying down of loose cables) can be an issue for long-term reliability. Most people will have to just assume an expensive monitor has no flaws in this department.
And lastly, something you may well forget in all the excitement. A smooth swivel action at the base (especially for heavy monitors) is not something you can take for granted and should be physically checked.