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LG L222WS refresh rate max 60Hz ?

Last response: in Computer Peripherals
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July 23, 2008 6:24:37 PM

Hello,

I recently bought an LG L222WS. My problem is that my eyes get very tired and red even after a short usage. I look at a monitor all day at work, but I don't have the same problem there.

My guess is that the monitor refresh rate could be causing the irritation. I can only set it at 59 or 60Hz at the Windows display settings. Is this the maximum refresh rate of L222WS, or am I missing something? I have a 8800GT video card by the way.

Any help would be appreciated.

Denes Toth
a b C Monitor
July 23, 2008 6:47:59 PM

The monitor is always on, so refresh rate wouldn't cause that (unlike a CRT, which flashes like a strobe light, and therefore needs a higher refresh rate). Try turning down the brightness though - that is quite a bright monitor, and that could be causing the problem.
a c 195 C Monitor
July 23, 2008 6:58:14 PM

CRT and LCD monitors operate differently, therefore "refresh rate" have different meanings for the two monitor types.

The CRT's cathoray guns shoots electrons to the cathoray tube from the top of the monitor all the way down to the bottom of the monitor, thus drawing one line at a time from top to bottom and then at the top once again. The refresh rate determines how fast these lines are drawn. The lower the refresh rate the more you will see the CRT monitor flicker and evenutally causes eye strain.

LCD monitors do not flick at all. The refresh rate refers to the data signal coming from the video card to the LCD monitor. All LCD monitors are set to 60MHz refresh unless the analog VGA cable is used which can sometimes boost it to 75MHz. But that is relatively meaningless since the LCD's electronics generally changes the signal from the video card backdown to 60MHz. The image on an LCD screen is constant until the image itself changes.

Possible causes of you eye strain (in my opinion):

1. Monitor's brightness is too high.
2. Contrast is either too high (colors washes out), or too low (colors are muted to the point of "gray-ishness").
3. Not enough lights in the room.
4. Perhaps the flourescent backlighting of the LCD monitor itself is causing eye fatigue.
5. Maybe text appears too sharp or too soft. Some monitors gives you the ability to adjust sharpness. For example, I set my monitor's sharpness to about 26% (off the top of my head).

Related resources
July 23, 2008 9:14:36 PM

Thanks guys, really useful comments. :) 

I will try tweaking the monitor settings.

Just one question - what if case 4 is true, jaguarskx? In that case it could be that I bought a monitor that is just not suitable for my eyes?

Anyway, thank you guys again for the clever comments.

(By the way, "optimal" brightness/contrast/sharpness settings from a sensitive-eyed :)  L222WS user would be greatly appreciated...)
a c 195 C Monitor
July 23, 2008 9:55:39 PM

Since you do not seem to suffer from eye strain at work it could be possible that you are sensitive to florescent lights, but there is enough natural sunlight coming through to offset the "negative affects".

Natural sunlight is full spectrum light. If you take a prism to breakup a beam of white light you will see all the colors in the rainbow.

Florescent light (eventhough it is white) does not emit the full spectrum, but has "enough" colors mixed together to produce white light (a.k.a. cool white, "soft" white is yellowish).

My suggestions would be:

1. Place an incandescent light bulb nearby (on of course) to see if that helps any. It's not full spectrum, but might be enough to reduce eye fatigue.

2. Buy a "full spectrum" incandescent light bulb which imitates natural light. You should be able to find it in a specialty lights store or a large store with a gardening section (for lack of a better term) like Lowes. These types of bulbs are used to grow plants indoors. There are florescent full spectrum lights too. These types of light bulbs are more expensive.

Hopefully that will help out with eye strain.

a c 195 C Monitor
July 24, 2008 2:00:44 AM

jaguarskx said:


LCD monitors do not flick at all.



Correction #1:

Typo => "flicker"

Correction #2:


There are actually some LCD monitors that are designed to flicker. But some background info first...

Most inexpensive monitors are built around the inexpensive 6-bit TN panel. While inexpensive this type of monitor has a major "flaw", it can only produce 256k actual colors. Each of the primary colors Red, Green, Blue are given 6-bits to store different shades of that color. Some basic binary math tells us that 6-bit color means there are 64 shades of each color. 2^6 = 2x2x2x2x2x2 = 64.

There are 64 shades of each primary color , that means 256k colors can be produced. The math is as follows:

64^3 = 64 x 64 x 64 = 262,144.

1,000 in computer terminology = 1,024

262,144 / 1,024 = 256k



Thru a process called dithering the remaining 16.5 million colors can be created. Dithering means blending colors together to produce a different color. For simplicity sake imagine a checkerboard, that will be used to represent the LCD matrix in a zoomed in view under a magnifying glass. If the LCD were to display red, then all the squares would be colored red. If the LCD were to display solid blue, then all the squares will display blue.

Let's say you wanted the LCD to display the color purple. Purple is a blend of red and blue. For simplicity sake, let's assume each square is incapable of displaying purple. Okay, the dithering process kicks in to "imitate" purple on the screen. To do so every other square will alternate between the colors red and blue. Up close you can clearly see that it is just checkerboard of red and blue. But step back. The further away you are from the checkerboard the more it looks like the red and blue are blended together to create what appears to solid purple.

The above is the traditional method of dithering. However, there is another version of dithering called Frame Rate Control or FRC for short.

FRC - To continue the example above, instead of alternate squares of red and blue to create the color purple, each square flickers very fast between red and blue. This flickering is so fast that you will not notice the flickering and it fools the brain into thinking it is seeing a constant shade of purple. What's the timing of the flashing between colors? I have no idea. Probably need one of those high speed cameras that can film 500+ frames per second used to film a bullet leaving the muzzle of a gun.



Does the LG 222WS use FRC?
Don't know no info is provided on LG's site.

Can FRC cause eye fatigue?
Unknown since there is no information about how fast a monitor with FRC switches between one color and another.
a c 195 C Monitor
July 24, 2008 2:12:45 AM

Additional info:

More expensive panel technologies like S-PVA, P-MVA and IPS are capable of actually displaying 16.7 million colors because each primary color (Red, Green Blue) will have 8-bits of data to represent the shades.

The math:

2^8 = 2x2x2x2x2x2x2x2 = 256 shades

256^3 = 256 x 256 x 256 = 16,777,216

Therefore, these panel techs do not need to use dithering. More expensive because the cost to produce them is higher.
July 24, 2008 5:54:33 PM

Thank you very much for your time, jaguarskx, these were really informative and useful answers! :) 

I will try out the things you suggested, hopefully my problems will pass.

Thanks again!
a c 195 C Monitor
July 25, 2008 5:14:58 AM

Click the following link which will help oyu manually calibrate your monitor. Perhaps it will help alleviate your eye strain.

http://www.lagom.nl/lcd-test/
August 22, 2008 1:40:35 AM

Hey buddy,

Was going thru the website of LG and some other website with the specifications of he monitor. the refresh rate is upto 75 Hertz. But it may not support the maximum refresh rates at high resolutions. So try reducing the resolutions and then try to adjust the refresh rate. Must work for you. And 75 Hrtz is good enuff.
a c 195 C Monitor
August 22, 2008 3:57:14 AM

Sam_Almighty said:
Hey buddy,

Was going thru the website of LG and some other website with the specifications of he monitor. the refresh rate is upto 75 Hertz. But it may not support the maximum refresh rates at high resolutions. So try reducing the resolutions and then try to adjust the refresh rate. Must work for you. And 75 Hrtz is good enuff.


From my first reply:

jaguarskx said:
The refresh rate refers to the data signal coming from the video card to the LCD monitor. All LCD monitors are set to 60MHz refresh unless the analog VGA cable is used which can sometimes boost it to 75MHz. But that is relatively meaningless since the LCD's electronics generally changes the signal from the video card backdown to 60MHz.

!