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DADDY BOB'S COMPUTER Q & A
June 29,
2008
Q.
I recently bought a wide screen monitor but
no matter what resolution I set it, the
picture is either distorted horizontally or
vertically. How can I tell what resolutions
a monitor can display correctly?
A.
When monitors were only 15 or 17 inch, this
was easy and pretty standard throughout the
industry. However, with the introduction of
19" and then wide screens, the resolutions
now vary greatly.
It
becomes easy to get the monitor's resolution
and its size confused. All monitor
resolutions are expressed in the form 1024 X
768 where the 1024 is the number of pixels
it can display horizontally and 768 the
number of pixels it can display vertically.
However, monitor sizes are measured in
inches by the distance between opposite
corners diagonally.
In
reality, a 20" widescreen monitor will
measure about the same top to bottom as a
17" non-widescreen one, but will be about 4"
wider. So, if set to the same resolution, it
will not be any taller, just stretched. So
what can you do?
Monitors
like TV screen resolutions can be expressed
as a ratio. Common ones for monitors are
officially designated as 4 X 3, 5 X 4, and 8
X 5. Most new monitors will specify the
maximum resolution they can display. Two
common resolutions for widescreen monitors
are 1920 X 1200 and 1680 X 1050. So, if your
video display adapter can be set to these,
it will display correctly on that monitor.
But suppose yours cannot be set that high.
How do you determine what resolution will
look OK?
This will
take a little math, but is pretty simple.
What you have to do is figure out the
monitor's ratio. If it is a widescreen with
a max resolution of 1920 X 1200, it will
probably be one of the 8 X 5 types. To see
if this is correct, start with the monitor's
horizontal figure, the 1920 in this case,
and divide it by 8. You get 240. Now
multiply this by 5 and you get 1200, the
monitor's vertical figure. This means it
does have an 8 X 5 ratio.
So now,
go to one of the resolutions your computer
can use. One common one would be 1440 X 900.
Will this display correctly? let's see'.
Start with the 1440, and dividing it by 8
you get 180. Multiply this by 5 and you get
900. So it will display correctly.
Another
common resolution many computers can use is
1280 X 1024. Will this one display
correctly? 1280 divided by 8 = 160. 160 X 5
= 800. Now 800 is not the 1024 required, so
the display will be distorted.
Still to
difficult to figure out? Ok, although not
the recognized as the correct way to do
things, here is the DaddyBob easier way that
I find works for me.
Using the
the monitor's screen actual measured size,
divide the horizontal measurement (across)
by the vertical measurement (up and down).
If you get an answer close to 1.33 then it
has a ratio of 4 X 3 and will correctly
display these common resolutions:
640 X 480
800 X 600
1024 X 768
1152 X 864
If the
answer is close to 1.25, then you have a
ratio of 5 X 4, and it will correctly
display this common resolution.
1280 X 1024
If the
answer is close to 1.6, then it has a ratio
of 8 X 5, technically usually referred to a
a ratio of 16 X 10, and will properly
display these common resolutions.
1280 X 800
1440 X 900
1660 X 1050
1920 X 1200
2560 X 1600
Most new
video display adapters are supporting the
widescreen resolutions shown above. This
doesn't mean that things cannot change in
the future, but for now it is the norm. Your
video display adapter may support more or
less that I have shown but this should give
you a guideline.
OK, one
final thought. Here is how you can see what
resolution your computer can and is using.
On XP, right click the desktop, choose
Properties and then the Settings tab. In
Vista, right click the screen and choose
Personalize. Select the last item n the list
called Display Settings.
The
resolution is displayed with a slide bar and
figure below it. Note what it is set
to so you can return to it later if you
want. Using the mouse pointer, move the
slide bar from end to end to see what
resolutions are supported by your video
display adapter.
To see
what you screen would look like at a
different resolution, click the Apply
button. The screen will go black then change
to the new setting. You are given 15 seconds
to click yes or no to keep the new setting.
Clicking neither the Yes or No is the same
as clicking no.
Should
you select a resolution your monitor cannot
display, it may tell you so, or just black
out completely. Not to worry, it will revert
back to the previous setting when the 15
seconds times out. |
