Re: An LCD for your IIGS?

[pausch@saaf.se (Paul Schlyter)]

In article <20030923134715.06379.00000041@mb-m20.aol.com>,
Michael J. Mahon <mjmahon@aol.com> wrote:
> Paul Schlyter replied:
> 
>>In article <20030921235449.16646.00001375@mb-m02.aol.com>,
>>Michael J. Mahon <mjmahon@aol.com> wrote:
>> 
>>> S-Video is quite different, since it has only two signals:  the Y
>>> signal (of potentially high bandwidth) and the quadrature
>>> modulated chrominance subcarrier, which is necessarily
>>> limited to less bandwidth than the subcarrier frequency
>>> (3.58MHz).  S-Video is better than composite (since the
>>> luminance signal will not be bandwidth-limited by separating
>>> out the chrominance subcarrier), but substantially inferior
>>> to RGB or component video (which have no intrinsic chroma
>>> bandwidth limitations).
>> 
>> OTOH you probably won't notice the difference, since the eye itself
>> has a worse chroma resolution than luminance resolution.  If you do
>> notice any difference, then you're sitting too close to the screen,
>> and you'll probably notice luminance bandwidth limitations as well.
> 
> RGB displays are noted for their ability to render pixel-level
> differences in color and luminance.  Smearing out the color
> changes over several pixels may be subjectively acceptable
> for video and photographic images, but it is not at all good
> for screens containing fonts and other fine color detail.
 
When displaying text on the screen, you should rely on luminance
contrast and not merely color contrast.  If you don't do this,
your text will be much harder to read.
 
> Any color-on-color detail which has little luminance contrast
> will be blurred significantly--comparable to a composite
> video display.
 
Very true --- but that blurring already occurs in our eyes.
That's why text depending on only color-on-color contrast is
much harder to read than text depending on luminance contrast
as well.
 
> Computer displays are usually viewed at a distance from
> the screen that renders indidual pixels visible, unlike video
> displays.
> 
> I point this out, because people are looking for a more
> abundant alternative to the IIgs RGB display.  It is important
> to understand the limitations of mapping RGB to more
> bandwidth-limited formats.
 
-- 
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