[geeks] 24 inch monitors

[Shannon Hendrix]

On Jan 1, 2008, at 1:20 PM, Phil Stracchino wrote:

> Shannon Hendrix wrote:
>> I have not totally dismissed a Samsung S-PVA display, but they do  
>> have
>> a couple of issues that worry me.
>
> How does one find out what specific TFT technology a given LCD  
> display uses?

You generally have to look for third party information, since almost  
no sellers or makers give that information.

There is a Denmark site that is pretty good:

http://www.flatpanels.dk/panels.php

You should be able to find a lot of displays and their panel types here.

Otherwise, just look around for a particular model and scan for a note  
from someone who has figured it out.

Also note that in some cases a manufacturer will change the panel  
type, but not usually in a single model number, and usually only on  
the cheaper displays.

The panel types are TN, MVA, PVA, and IPS, with some variations like S- 
PVA, U-MVA, etc.

TN is the fastest, but has the lowest image and color quality.

MVA is a hybrid of TN and IPS, with a slight tendency to have worse  
pixel failures.

PVA is the overall best, but some makers use faulty overdrive circuits  
that cause ghosting on some of them, though firmware updates can  
usually fix that.  PVA has excellent black.

IPS is the best overall color and image color, but it is slower than  
the others, and the blacks are not as good as PVA.

In other words: LCD technology is still evolving, so you'll never find  
perfect.

The idea is to find the best compromise for the majority of what you  
use it for.

LCDs were improving for awhile, but then gamers started to complain  
about speed, so the industry moved largely to TN based panels which  
are fast, but suck for anything but gaming or office use.

Gaming and price has a heavy influence on the LCD market.

However, now the gamers are starting to complain about the quality of  
TN, so there is a slow move back to better panels and making them run  
faster but still give good image quality.

This has resulted in more new MVA and PVA displays, but some growing  
pains in the new technology to make them faster.

For example the Dell 2407 initially had serious color problems in the  
A0 and A1 revisions, and severe shadow ghosting.

But the latest versions of their S-PVA based 2407 HC is supposed to  
have fixed the ghosting and color issues.

The remaining issue is input lag, and it isn't too bad for a 24 inch  
LCD.  A lot of people probably wouldn't even notice it.

The way to tell is to do this:

Hook two displays to your computer, one LCD and one CRT.

Mirror the image to both displays and display a clock that has at  
least thousandths of a second accuracy.

Take a series of photos of the display, and you should be able to see  
the clock on the LCD is a few milliseconds behind the CRT.

You can also do this with sequence test movie frames like those used  
to calibrate movie projectors.



-- 
Shannon Hendrix
shannon at widomaker.com