Most of the people who don't see a difference don't know how to evaluate
a monitor. I've been in the display business, and the difference to a
trained eye is usually significant. Put up a test pattern of
alternating black and white vertical bars, each one single pixel wide,
and with an analog input there is usually some bad moire distortion
present. Also, there is usually some "ghosting" or "ringing" around
very sharp transitions -- like the vertical parts of white or black
characters on a black or white background, when the character component
is only a single pixel wide.
Lots of people don't see these things, just like lots of people can't
tell the difference between a $50 radio and a $2,000 stereo system. But
if you show them to people, they will never again be happy with things
that they used to be perfectly satisfied with. In any case, however,
DVI images are totally free of these problems, so why fight it.
By the way, a test program that will put up the bar display is available
free. It can be used to correctly adjust the dot clock on an analog
monitor:
http://www.winsite.com/bin/Info?500000030936
This program is variously known as CRTAT, CRTAT2, and CRT Align
(crtalign), and was written by Stephen Jenkins in about 1992 or 1993.
To use the program for this purpose, after installation, select the
leftmost of the 3 functions in the "Test" group and then check both
check-boxes. This is a very old Windows 3.1 program written in visual
basic. It runs under XP just fine, absolutely perfectly in fact, even
with today's high resolution monitors (you do need VBRUN300.DLL (the
Visual basic version 3 runtime DLL library), which it may or may not
come with it depending on where you download it from, but if you don't
have VBRUN300.DLL, it can be easily found on the web).
This program is totally non-invasive, it's "installation" makes NO
changes to your registry or to ANY system components or files. In fact,
if you just unzip the program and double click the exe file, it will run
fine without actual "installation" (but the program and the help file
need to be in the same directory, and VBRUN300.DLL needs to be available).
When you display this pattern, you should see an absolutely perfect and
uniform field of alternating (but very, very fine) black and white
vertical bars each only one single pixel wide. If you see "moire"
distortion, or smearing, your display isn't adjusted correctly. Digital
monitors (with DVI interfaces) will always be "perfect". Analog
monitors will usually show an initial moire distortion pattern until
they are adjusted (dot clock frequency and phase). In most cases,
perfect adjustment can be achieved (and is "remembered" by the display),
but in some cases you can't achieve this. Note that the "auto"
(auto-adjust) function on almost all analog LCD monitors gets "close"
but usually does not get to the best possible adjustment.
If you have an analog monitor and you don't use this program to adjust
your monitor, you are doing yourself a real disservice.
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