[geeks] LCD display options

[Joshua Boyd]

On Thu, Feb 24, 2005 at 09:33:29AM -0600, Mike Parson wrote:

> > Lowest pixel refresh rate?  Specified in units of frequency, I assume?
> > I don't quite grok.  Or is this specified in units of time, so that you
> > want the shortest time between refreshes?
> > 	Greg
> 
> It's specified in units of time.  If you look at the spec sheets for the
> LCD monitors, they print the pixel refresh times in ms.  For gaming, you
> want something around 12ms or so.
> 
> For text work, or anything that you don't mind a little ghosting, the
> cheaper ones that push closer to 20ms are fine.

While many gamers call it pixel refresh rate, they are wrong.  LCDs
don't refresh.  The number is usually called Response Time, but
sometimes it is called latency.  

Personally, I wouldn't buy a display that had a response time more than
16ms for normal computers.  The issue here is that typically you can't
set the graphics card's refresh rate below 60hz, and 16ms is the
response time needed for 60hz display.  20ms would be fine for a 50hz
display, but if the computer won't let you go that low, then you WILL
have the stereotypical LCD display blurriness on motion.

Some displays advertise 12ms response times, which would be good for up
to about 83hz refresh rates, but really, what is the point past 72/75hz
(and the 72 only for certain niche professionals and the 75hz for
Europeans and other PAL areas)?  On CRTs, the idea of higher refresh
rates was to get rid of flicker, but LCDs don't have flicker, even if
you drive them at only 48hz or 24hz.  Thus, the only reason to pick one
refresh rate over another with LCDs is to match some other number (or an
integer multiple of that number).  In particular, 59.94 hz in the US and
other NTSC areas, 50hz in Europe and other PAL areas, and 24 hz for
people working on NTSC material instead (which could be people actually
working on film, or even people only working on DVDs).  And that is only
to support showing video on the screen as nicely as possible.  For all
other purposes, refresh rate really doesn't matter on LCDs.

-- 
Joshua D. Boyd
jdboyd at jdboyd.net
http://www.jdboyd.net/
http://www.joshuaboyd.org/