Questions for people who know about displays

A

Abijah

n00b
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Dec 2, 2008
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Hi there,

I have some questions about displays that I know some pro in here can handle. So here it goes.

I just purchased an HP a6642p desktop. 6gigs of Ram, 500gb hdd, on board video (intel 256mb), realtech audio (or whatever it's called), vista 64-bit home premium. Blazing fast for what I do.

Ok, the computer came with a flat panel monitor (of course). The HP w1907. 19", 1400x900 @ 60hertz. http://reviews.cnet.com/lcd-monitors/hp-w1907/4505-3174_7-32399889.html

I haven't had a desktop in ages (over 5 years). I used to build my own desktops and used CRT monitors because flat panel technology was expensive and the image quality wasn't good enough. (CRT offered better screen area resolutions and hertz rates for design work that I did.)

Here are my questions. I noticed right away when I set up the PC that as I moved me eyes around on the screen I could see the pixels [kind of] vibrating (for lack of a better term) for about .5 seconds before my eyes adjusted. Once my eyes adjust to the 'flicker' the pixels go away, until I move my eyes to another part of the screen then my eyes have to re-adjust again. (My mind "interprets" the image.) However, I notice that the pixel flicker is really annoying and is bothering me, and even contributing to headaches (I think).

What is causing me to see the pixel flicker for .5 seconds?
Is it the Hertz rate? (60)
Is it the Clock or Clock Phase? (I adjusted these using the HP software)
Is it the response time? (5-millisecond pixel response time)
Is it the pixel pitch? (0.258 mm)

I've always had a sensitivity to monitor flicker and other imperfections, so I realize that most other people (my wife included) don't even notice this pixel vibration.

Finally, I plan on buying a new monitor. What should I look for in a monitor to make sure that I don't have this problem?

What is a good flat panel with an EXTRA high resolution at a high refresh rate - assuming that's what is causing the problem.

Thanks in advance for your input and advice, I really appreciate it.
 
Sounds like it may be the type of dithering used to get more colors than the panel can normally do.
 
RacerJim,

Thanks for your reply!

Now that you mention it, it kind of looks like dithering. I'm don't know much about dithering on monitors.

Can I purchase a monitor that won't do this dithering? Is is something that is clearly advertised? I don't remember seeing dithering information on monitor specs. What kind of monitor should I buy so that I don't run into this problem?

THANKS!
Adam
 
It isn't really advertised at all, sadly. Your monitor is using a TN panel, which all use some form of dithering. If you want to avoid dithering altogether you will have to look at PVA or IPS panels. They are much more expensive and relatively harder to find (you won't find a 19" without a TN panel). I'd do a search in this forum for some suggestions.
 
So the panel relates to dithering I guess. Well, I can certainly look around for a PVA or IPS. I notice that none of the laptop monitors I have used for the last several years have had this problem, they're all very crisp and clear. Are laptop monitors PVA/IPS? Or is there another reason that laptop monitors don't seem to give me this problem?

THANKS AGAIN!
Adam
 
I tell you what, this monitor is driving me crazy. I can totally see the dithering and it's driving me crazy. I have to sell this monitor ASAP and buy a new one.

Do you think it would matter if I used a DVI connection? Probably not.
 
first are you running vga?

Second your video seems like it is onboard. alot of onboard video chips seem to have a blurry output degradeing it vastly compared to an aftermarket daughterboard based vga chipsets. This is caused by a cheap dac. i would try another vga cable are a dvi before chunking it.

Does it look like a screendoor somewhat. you may want to check and see if any pins are bent are if the cable is getting a good connection.

p.s. i could be way off but just trying to help.

If you want a good big cheap ips that has low input lag for gameing try the planer px2611w
 
What you are probably seeing is temporal dithering, which flashes between two colors to fake a different color. Static dithering doesn't flash but looks worse.

You should try borrowing another LCD and see if your problem persists.
 
temporal dithering. Ok.

Basically what I'm seeing is the pixels shaking in the area where my eyes are focused, it only lasts for second until my brain interprets the image. I guess I'm just slow.
 
after you explained it that way seems i jumped a bit overboard sorry. that is most defenitly dithering at it's best(or should i say worse;))
 
I went out and purchased a ViewSonic VX2260wm 22" 1080p Full HD HDMI. It fixed the problem with my eyes seeing pixel 'flicker'. I also purchased a full HD video card to replace my on-board video, but then I realized I need to put in a new [420 watt] power supply to power it.

I'm running off on-board video right now, which means I'm at 60 hertz, which kills my eyes. I wish my brain wasn't so picky! Anyway, I have to buy a power supply to run my video card so that I can get 1080p HD at 120hz !

Thanks to those who replied. Any suggestions on a power supply? I'm looking at geeks.com and they have some amazing prices - between 13.00 and 30.00 at the high end.

I'm looking at Echo Star, Green, A-Power, Logisys, and others.
 
Your not going to be able to run at 120hz with that setup. Most lcds will take an input of 60 hz and draw 60 frames per second if your video card can output that fast. if the lcd is set to 120 hz within the osd it will just emulate frames inbetween each frame. so it's as smooth as 120hz but not true 120hz.

Also in adding these extra frames the tv does the proccessing in which adds proccessing time which makes for high input lag. Ok if your watching movies but playing games is a nono. most panels right now can't be pushed anyfaster than about 75 hz before they just don't do anything with the faster refresh signal. most of these won't even let you input a higher refresh than 60 hz. so I would buy a better video card and power supply for cleaner video but your not going to be able to do it just yet. Thats the hailmary of lcd's.

Edit when you say it kills your eyes what are you referring to. Lcd's don't really flicker.

if i was to take a 60hz lcd each hz is 1 frame. that on an lcd would just draw 60 fps. on a crt that would draw 60 flickering fps. if you were to run your crt at 2 hz you would see a white line move up and down the screen 2 times a second. on a lcd it would be the equvilent of looking at 2fps in a game with no flicker. increasing the frequency would just give a smoother image as if more fps were achieved by unlocking the 60hz cap on your video card. it would look like 70 fps at 70hz then there would be a point that you would get to that the response time of the pixels changeing wouldn't get any faster thus increasing your signal would give you artifacts somewhere arount 75 hz. resulting from the frame changeing before the pixels had time for the slowest pixel to transition. 120 hz as of now is kinda pointless on some tv's if they don't have a low enough response time.
 
Sathsayin,

Thanks for the great reply. I didn't realize that the LCDs were holding back the refresh rate to 60 or 70hz. I was used to using CRTs which could do just about anything.

I'm still going to setup a new power supply and the new video card I bought. If I get a blue ray drive, and/or PS3 I should be able to get Blue Ray HD because both my monitor and new video card claim that they do 1080p HD.

Anyway, I'm not a big gamer or anything, I just figured since I have some money to upgrad I might as well take advantage of better video. It's the only thing my PC lacks.

I understand the hertz rate stuff. It's not that I visual see the flickering. I don't see the screen flickering like a CRT, but I do notice the 60hz refresh to some degree. Maybe I'm just a hypochondriac, but I feel like I can see the refresh just a little bit and it's bothering me.

Anyway, thanks for the great response! I'll keep this stuff in mind as I work with my new video card.
 
to be honest im in the same boat with lcd's comeing from a highend crt


alot of people will argue there is no diffrence when there really is. its not about the flicker its about the smootheness of the image created at a higher frequency(lcd faster image update) at 60hz on an lcd its not the flicker like i said its more are less the smoothness created at around 90-100 hz on crts the flicker stops around 77 hz so people always want to equate that you don't need to have anything faster on an lcd.


if you forget the entire 60hz thing and look at it simple
crt 2hz is a line scrolling up and down 20hz is a strobeing stuttering slideshow. 30hz is horrible flickering playable 45 is flickering decent headache 60 is flickering good playable game. 70 is barely flickerable exccelent. 90 is no flickering exccelent game.
lcd 2hz is 2fps its a slide show 20hz is 20 fps is stuttering slideshow 30hz is 30 fps is playable 45hz 45fps is decent 60hz is 60fps is good and 70hz is 70fps and above is excellent. i run my monitor at 73hz at 1680 by 1050 thru powerstrip.
 
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