How can a fast response time LCD possibly have a wider color gamut
when it is only displaying 6bits per pixel?
Ah, I see - the typical confusion between "dynamic range" and
"color gamut." Let's see if we can clear this up...
"Color gamut" refers to the range of colors, within the full color
space usable by human vision, that can be reproduced on a
given display. It is often given as a percentage of some reference
gamut (e.g., "72% of NTSC"), but more precisely is defined by
stating the chromaticities of the primaries used by that device. It
is, in simple terms, an area or volume (depending on whether you're
working in a 2-D or 3-D color model) which defines the colors
that can be produced by the display. It is NOT related to the
*number* of different luminance levels or "gray values" which can
be produced by the display (within the gamut area or volume) for
any given primary (which is what the "bits per color" figure means,
and which is more properly called "dynamic range." You CAN have
a display with a very, very wide gamut which provides only 2-3
bits/color, although why someone would want such a thing (at least
in most technologies) is beyond me.
An analogy: Suppose I have two parcels of land, one of which is
a square mile in area while the other is only 20 acres. I divide
the 20-acre parcel up into 80 lots, though, while I leave the square-
mile bit intact. That I have a larger number of discrete lots
within the 20-acre parcel (the larger number here being analogous
to the dynamic range) does not change the fact that the overall
area of that parcel is still considerably smaller than a square mile
(which is analogous to the gamut question).
And you do this for a living?!
Yes, I do; and I think we're seeing why you don't, perhaps.
I've already done the research and I'm not going to hold your
hand and waste my time looking it all up for you. Go read about
various types of LCD panels used and how they achieve 4ms repsonse
time in the "gaming" dispalys. Here, I'll start you off.
You would do well to extend your research to something other
than "pop-science" level articles aimed at lay consumers. While
restricting the dynamic range HAS been used in some methods
for improved response time, it is by no means NECESSARY to
achieving that goal. In short, it is one possible technique (and
within the range of available techniques, sort of a "quick-and-dirty"
one), but by no means the only one available. Various other
methods have being used (and are being used) to achieve lower
response times, including the use of completely different LC
modes (check out "OCB" - optically-compensated "bend" -
panels, just for one example). For that matter, restricting the
available dynamic range or accuracy *over a single frame time*
is not always necessarily a bad thing, since the eye won't
respond that quickly to the lower bits anyway - as long as a
given area winds up at the proper level (to 8-bit or, in some
cases, now even 10-bit accuracy) within 2-3 frames of the
transition, that will generally be more than adequate. Unless,
of course, you're claiming you can see a subpixel varying between,
say, level 132 and level 133 (out of 255) on alternate frames.
Now color depth was previous referred to by the total number of colors
that the screen can render, but when referring to LCD panels the
number of levels that each color can render is used instead. This can
make things difficult to understand, but to demonstrate, we will look
at the mathematics of it. For example, 24-bit or true color is
comprised of three colors each with 8-bits of color. Mathematically,
this is represented as:
* 2^8 x 2^8 x 2^8 = 256 x 256 x 256 = 16,777,216
This, however, is not "gamut." The value given here is a function of the
dynamic range on a per-color basis, and is not related to the
chromaticities of the primaries.
This is very subjective to the actual user and what the computer is
used for. The amount of color really matters to those that do
professional work on graphics. For these people, the amount of color
Let's note here that "amount of color," as it is being used (possibly
misused) by this writer is an extremely ambiguous term. What is
really meant here?
All in all, the most charitable thing that can be said about this article is
that it's not too inaccurate for use by the lay reader, but it certainly
does not give a technically accurate description of how these factors
relate, and it is very quickly being rendered obsolete by advances in the
industry.
Bob M.