"Pipboy" <no (AT) email (DOT) invalid> wrote

GTG is indeed a superior measure than the average response time when it's
done properly, and yes, in certain cases it can be slower than the average
(it can be faster too). Given the stick manufacturers have taken from
people who know what they're talking about over not providing GTG times, if
I were you I'd be pleasantly surprised you found one trying to do the right
thing.

Pipboy wrote:

I don't think you did, although you may have misinterpreted what he
said. I'll forgive you for that, since Bob is known to have similar
difficulties with what he reads-into what others write...

"Bob Myers" <nospample... (AT) address (DOT) invalid> wrote:

That was where I sent my GDM FW-900
for refurb before selling it on eBay a couple
of years ago.

Sony could have moved the operation, but
I suspect they still do hi-end refurbs somewhere,
as many CRT users are clearly unwilling to move
to LCD yet (and if I were in heavy pre-press, I might
be buying all the Artisans that turn up on eBay :-)

So let me update the eBay advice:
Buy Sony.
But first find out where you'll need to Fedex it
for refurb (and Fedex was by far the cheapest).

--
Regards, Bob Niland mailto:name (AT) ispname (DOT) tld
http://www.access-one.com/rjn email4rjn AT yahoo DOT com
NOT speaking for any employer, client or Internet Service Provider.

"Pipboy" <no (AT) email (DOT) invalid> wrote


It could certainly be me who said that, and it's not a lie at all.

For most LCD technologies in their basic form, the gray-to-gray
response can and many times WILL be far longer than what it takes
for the full white-to-black or black-to-white transition. The reason
for this somewhat counterintuitive situation is that the LCD is really
just a "light valve" sort of device that relies on the molecules of the
LC material switching between two states (or to various
intermediate states) in response to a voltage applied across the
material. The problem is that the voltage difference between any
two gray states, or white or black and an intermediate state, is
obviously less than it's going to be when doing the full white-to-black
transition. Less voltage change means, simply put, that the molecules
aren't being "kicked" as hard (less force to make the transition), and
so the transition is slower.

The solution to this in modern panels is "overdrive," which is a method
in which a higher voltage than is needed for the intended gray level is
initially applied across the LC, and then the voltage is reduced on
subsequent frames until that cell "settles in" to a stable gray state.
This method improves the GtG response significantly over what it
would be with the staight drive, but does nothing to improve the full
white/black transitions (since for most drivers, you can't apply a voltage
in excess of the "full white" or "full black" level). So we wind up with:

1. The basic (w/o overdrive) GtG transition IS often slower than the
full black/white changes, AND

2. With overdrive, GtG can be faster than the black/white, which
typically is not improved by this method.

For the full story on what the display is going to actually look like, you
need to look at BOTH specs (plus, due to other methods that are
now being applied to LCDs, yet another spec called the "motion
picture" or "moving edge" response time - which is only somewhat
related to the other two).

Glad to be able to clear that up.

Bob M.

"Pipboy" <no (AT) email (DOT) invalid> wrote

Mine does, too. I worked on my first LCD monitor design in
the late 1980s. At that time, the panel alone (which was by no
means a 17") cost several thousand dollars in small production
volumes. The sole benefits were that it enabled a thin, light
monitor that wasn't troubled by magnetic fields, which was a big
deal for several customers at the time.


Bob M.

"Bob Myers" <nospamplease (AT) address (DOT) invalid> wrote


[...]

I've read of problems with overdrive. If the voltage is too high it can
produce bright artifacts around moving objects.

"DRS" <drs (AT) removethis (DOT) ihug.com.au> wrote

That can certainly happen, and has on some of the early overdrive
panels; clearly, it will depend a lot on how well the overdrive
circuitry/algorithm is implemented, and secondarily whether or not
it can compensate for other factors that may influence the basic
response time of the LC cell. There's also a potential problem, if the
monitor design is not done carefully, when an "overdrive" panel is used
with a scaler/controller IC which itself implements an "overdrive"
function (i.e., some monitor scaler/controllers can be set to implement
overdrive by feeding the panel with intentionally high values for the
first frame after a gray-level change; if the panel already is doing
overdrive on its own, though, you can imagine the trouble this could
cause). It's like most things - there's a right way and a wrong way
to do it.

Bob M.

On Fri, 09 Feb 2007 19:22:26 GMT, Bob Myers wrote:


Ah, now the truth comes out. You have a vested interest in LCD technology.
Yep, it was definately you who fed me the BS way back.

On Fri, 9 Feb 2007 21:31:21 +1100, DRS wrote:


BtW is the standsard and not GtG. They use GtG because it makes it look
faster than it really is. Look, another twerp trying to feed me BS.

On Fri, 09 Feb 2007 19:19:44 GMT, Bob Myers wrote:


That's not what I read when I researched it on the internet. Still, some
use GtG and others use BtW. That means they use whatever makes their LCD
look the fastest.