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gernb
Aug 30, 2004, 03:33 AM
OK...not sure what's going on here. I've had the new 23" for about 3 weeks. I am using it with my 12" Rev C powerbook.

When I change apps or close windows that are bright and have been open for a while (indesign, safari, a few others) there appears to be a ghost of that window left on the screen.

my desktop is set to medium grey. the effect is almost like a mild "burn in." After a while it goes away. But it doesn't seem like I can force it to go away just by dragging a window over that area and forcing a screen redraw.

Anyone have this problem or have an idea of what's causing it? How do I know if it's the video card in my pbook or the monitor itself?

Big thanks in advance.

emw
Aug 30, 2004, 09:51 AM
This is more likely a function of your eyes and not the monitor. This is similar to looking at a bright light (not the sun, of course) and then looking away at a dim area or closing your eyes - you continue to see the remnants of the bright light for a few seconds or more.

If your monitor is set to maximum brightness (which is pretty bright on the new 23") and you're looking at it for an extended period of time, you're actually getting "burn in" on your eyes.

To see if this is indeed the case, you could leave a window open for awhile, but don't look at it. Just launch it, then walk away for coffee or something, then come back and quickly close the window before you spend much time looking at it. See if you get the same phenomenon or not.

Also try turning down the brightness.

Veldek
Aug 30, 2004, 10:44 AM
This is more likely a function of your eyes and not the monitor. This is similar to looking at a bright light (not the sun, of course) and then looking away at a dim area or closing your eyes - you continue to see the remnants of the bright light for a few seconds or more.

If your monitor is set to maximum brightness (which is pretty bright on the new 23") and you're looking at it for an extended period of time, you're actually getting "burn in" on your eyes.

To see if this is indeed the case, you could leave a window open for awhile, but don't look at it. Just launch it, then walk away for coffee or something, then come back and quickly close the window before you spend much time looking at it. See if you get the same phenomenon or not.

Also try turning down the brightness.

You are kidding, right?

Well, I heard at least one story about the same effect, don't know if this was you, though. You could do a search in these forums. I'd also have a look in the Apple Discussion forums for similar things.

vraxtus
Aug 30, 2004, 10:46 AM
You are kidding, right?

Wait, he WASN'T joking???

:eek: :eek: :eek: :eek:

emw
Aug 30, 2004, 10:55 AM
You are kidding, right?

Actually, I'm not.

With LCD screens there is no such thing as "burn in." The reason that CRTs get it is because you are firing electrons at a screen and literally causing phosphors to "ignite" in order to give you color. Leaving an image on a CRT screen means that the electron guns are firing in the same place for an extended period of time, resulting in the burn in effect.

With LCDs, the lamps are on all of the time and the screen is controlled by opening and closing "gates" to the the screen through Red, Green, and Blue filters. Leaving these filters open for extended periods of time will not result in a burn-in effect. Screen savers on LCDs (and even most newer CRTs) are for enjoyment, not practicality.

The phenomenon that gernb describes has nothing to do with burn-in, and should also have nothing to do with pixel response (it sounds like it takes a few seconds to go away). In fact, for the LCD to "gradually" fade back to normal, it would require that the "gates" be gradually closed over time, which requires specific electrical input to the controls. This would seem to be highly unlikely.

You can duplicate the effect by staring for a long period of time at a bright white window on your monitor then closing it and looking at a blank gray background. Or at a dark wall, for that matter.

technocoy
Aug 30, 2004, 11:18 AM
on my 22in ever since i bought it.. it never stays permanently and i have only experienced it on solid darker greys and blues... burn in on your eye moves with your eye.. this stays in the exact spot on the screen. it's definitely something with the screen. I haven't had any problems with it though... it has gone away consistently for over two years...

i wouldn't worry

kgarner
Aug 30, 2004, 11:32 AM
I think emw is right on this one. The contrast of the gray background to the white forground could easily cause this and explain the gradual fade.

vraxtus
Aug 30, 2004, 12:14 PM
I think emw is right on this one. The contrast of the gray background to the white forground could easily cause this and explain the gradual fade.


No offense but you'd have to be an idiot to think that this is what's going on... something like that it is incredibly noticeable outside of the display.

gernb
Aug 30, 2004, 12:14 PM
Thanks for the replies. I'll keep looking into this.

I understand the suggestion about the effect being in my own eyes, but that isn't the case. If I look away from the screen, or even at another part of the screen, the image doesn't follow.

My guess is it's something to do with redraw. I just think it sucks that a $2,000 monitor can have this kind of flaw in it.

keysersoze
Aug 30, 2004, 12:36 PM
No offense but you'd have to be an idiot to think that this is what's going on... something like that it is incredibly noticeable outside of the display.

:D
Yes, my guess is it would affect other aspects of your daily life...
I think I'd get my display checked out by Apple before having eye surgery.

kgarner
Aug 30, 2004, 12:46 PM
No offense but you'd have to be an idiot to think that this is what's going on... something like that it is incredibly noticeable outside of the display.
Well, none taken. :D I just know that after looking at a display for a long time I notice some of the same effects. But noticing that the original poster says it happens even after short times, it may be a defect.

vraxtus
Aug 30, 2004, 12:51 PM
Well, none taken. :D I just know that after looking at a display for a long time I notice some of the same effects. But noticing that the original poster says it happens even after short times, it may be a defect.


Yeah, I know there have been several threads about this kind of thing happening, so I'd be much more suspect of the display rather than my eyes... so I guess I just parroted keyser, but yeah, you get the point :o

emw
Aug 30, 2004, 12:59 PM
No offense but you'd have to be an idiot to think that this is what's going on... something like that it is incredibly noticeable outside of the display.

Why would I possibly take offense at someone calling me an idiot? ;)

We just too often blame equipment or technology for things that really aren't their fault. In the initial post, my explanation was reasonable. Given the latest post by gernb, I'd look to the display, although I still find it difficult to understand how the technology used in LCDs could lead to this behavior.

vraxtus
Aug 30, 2004, 01:06 PM
Why would I possibly take offense at someone calling me an idiot? ;)

We just too often blame equipment or technology for things that really aren't their fault. In the initial post, my explanation was reasonable. Given the latest post by gernb, I'd look to the display, although I still find it difficult to understand how the technology used in LCDs could lead to this behavior.


I meant you as in the general "you" as in "you all" or "anyone" would be an idiot to explicitly think, in that moment, while looking at your screen, that you have a serious eye problem that is causing a burn-in image when you look directly, with no eye movement whatsoever, while closing a window, and seeing a burn in image, while remaining... completely... motionless...

:D

blutfink
Aug 30, 2004, 01:49 PM
This topic is discussed here (http://forums.macrumors.com/showthread.php?p=1012392), too.

I have put up a demonstration page (http://homepage.mac.com/leofink/green.html) [mac.com] to exploit the problem.

Seems like some panels don't have these issues, at least not in connection with PowerBooks. But from what I've seen, most of them do.

emw
Aug 30, 2004, 02:04 PM
...you have a serious eye problem that is causing a burn-in image when you look directly, with no eye movement whatsoever, while closing a window, and seeing a burn in image, while remaining... completely... motionless...

:D

Luckily it's not a serious eye problem - it's an evolutionary "defect" if you will, called chromatic adaptation. We all have it and experience it every day. You can even duplicate it at home. :)

But, assuming that this is indeed a display issue and not a pure physical response, let's figure out how it could happen.

Again, with LCD displays, the lamps burn at a constant brightness, no matter what is displayed on the screen (unless, of course, it is off). This is part of the reason that you can never really get as good a black on an LCD as you can on a CRT.

Anyway, the LCD gates on the screen rotate based on an electrical input, essentially translating to a standard 8-bit signal (0 to 255). When the screen receives a signal to display a white value, the doors on the gates open wide to allow significant light through. When the window closes, the gates now receive a signal to switch from mostly open (say a 240) to something closer to a dark gray, perhaps a 60 or so.

Now, if the latent delay is typical, then we should also see it when changing from the dark screen to a light screen. That is, there should be no more delay switching from a 240 position to a 60 position than from a 60 position to a 240 position. If that is the case, then we should see our bright white windows gradually getting brighter as the gates open all the way.

Note also that if the gates are that slow to respond, it would impact other things as well - such as how fast type appeared on screen or how fast windows scrolled, etc. It should not impact only the change from bright white to dark colors.

So while it may sound like I'm describing some horrible physical defect, I'm not. It happens all of the time. And while, yes, if the screen is truly really bright (such as sunlight reflecting off of metal or glass) you would see the effect if you looked away from your screen. However, if you work in a daylight or office environment, your surroundings are likely close the the brightness of the display.

So try this. Make your room really dark, so that it is at least as dark as the gray of your background. Now stare at a fully white window and then look off to the side at your dark windows. You will likely see the same thing as closing the window, albeit to a lesser degree. And this can happen if only after a few moments - you don't have to look at it for very long.

emw
Aug 30, 2004, 03:49 PM
This topic is discussed here (http://forums.macrumors.com/showthread.php?p=1012392), too.

I have put up a demonstration page (http://homepage.mac.com/leofink/green.html) [mac.com] to exploit the problem.

Seems like some panels don't have these issues, at least not in connection with PowerBooks. But from what I've seen, most of them do.

Let me guess - it's mainly the bright ones.

Also, it's a good thing we can always rely on our eyes to show for sure what is happening...

Check out this optical illusion (it isn't an animation) -

http://homepage.mac.com/thewoods96/macrumors_share/FileSharing10.html

:D

vraxtus
Aug 30, 2004, 04:02 PM
Let me guess - it's mainly the bright ones.

Also, it's a good thing we can always rely on our eyes to show for sure what is happening...

Check out this optical illusion (it isn't an animation) -

http://homepage.mac.com/thewoods96/macrumors_share/FileSharing10.html

:D



So.... all of the people having problems with their LCDs are imagining it... riiiiiight... -_-

emw
Aug 30, 2004, 04:59 PM
So.... all of the people having problems with their LCDs are imagining it... riiiiiight... -_-

I didn't say they were imagining anything - my posting is simply an interesting visual experiment. My point is that our eyes play tricks on us, which you apparently fail to understand.

To your point, I acknowledged in my earlier post that given what some people have seen, it was indeed a possibility that the displays were defective. And you'll have to pardon my incredulity, but we run over 250 20" cinema displays, both old and new, as well as older 22" ACDs, and we have never seen this problem.

I am, however, passing this information on to my Apple engineering contacts to see what they can tell me.

vraxtus
Aug 30, 2004, 05:29 PM
I didn't say they were imagining anything - my posting is simply an interesting visual experiment. My point is that our eyes play tricks on us, which you apparently fail to understand.


No... I do understand it. My point is that... there's not really much point in pointing out that point, since it's rather pointless since most people have acknowledged that it's not their eyes, but the screen, rendering your point rather pointless against the other points that have been pointed out.

gernb
Aug 30, 2004, 05:39 PM
Thanks for the thoughts...it sucks but my only solution was to exchange the 23" for a new 20" which does not appear to have the problem. What really closed the deal was that I realized from some other threads that I am not imagining things and the new 23" have a pink cast to them.

I took mine in to the Apple store and they hooked it up next to another 23", then set up a couple of 20"s next to them and they were suprised to say the least.

They were very cool about it...said they hadn't noticed that before, but now that they had they were going to start looking around for some answers.
In the mean time, if you've got this problem or are thinking about buying, check out the discussion forums at apple support for more on these issues.

Anyway, less screen real estate but also put $700 back in my pocket. Now I can pay for my daughter's day care this month!

keysersoze
Aug 30, 2004, 06:31 PM
No... I do understand it. My point is that... there's not really much point in pointing out that point, since it's rather pointless since most people have acknowledged that it's not their eyes, but the screen, rendering your point rather pointless against the other points that have been pointed out.

oh that's good! :)