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Green Lantern

macrumors member
Original poster
Aug 23, 2007
32
0
Just got a 24" iMac this past weekend, love it. However, I have noticed a light "Halo" at the top left part of the screen. It almost looks like the back light is bleeding over to the top of the screen. It is only visible when the top of the screen is dark or black, such as when watching a letterbox movie. They also appear along the bottom of the screen just not as bad. Has anyone else noticed this?
 
It won't be going away most likely. It is backlight bleed and is due to poor manufacturing standards as well as the poor concepts of lighting we have in place for LCDs thus far.
 
Is this considered 'normal' or should the OP consider having his iMac replaced?
 
Good, question...Is this normal? I am going back to Apple store this weekend to see if I notice it on any of the screens in the store. I will make my decision after that. Any advice would be great.
Thanks,
GL
 
I have a 17" C2D 2 GHZ "white" iMac. I was able to reproduce what you are talking about only when watching a letterbox movie with all the lights off in the room. I have a "halo" line across the top of the screen where it looks like a little light is escaping. Not enough to bother me. Sounds like yours might be worse.
 
Took back to apple store for replacement. I have to say they where great, didn't even question it. Took mine, migrated all information to a new one, had me out in 40 minutes. As soon as I got home I turned off all the lights and played a few movies in letterbox. The new one still has a few halos along the bottom of the screen, but nothing near as bad as the first one. All in all I'm pretty happy with the iMac and the service from the local Apple store.
 
I think a good amount of the iMacs has got backlight bleeding, some of them worse than others. So I guess it's would be "normal". But I bet that you can return it if it bugs you a lot.
I had slight bleeding on the one I returned, but not enough to make me return it for that reason.
 
yeah, i've got some backlight bleed as well on my 24" iMac.
but i'm not too worried about it - i got a display with no dead pixels and that is more important to me.
have any of you messed with the color profile yet? people say the 20" ships with a lousy profile and have posted a fix. the 24" looks good, but, when comparing color in say illustrator to what gets displayed normally - there is a huge difference on some colors.
 
Haven't messed with the profile yet. The factory standard on the 24" doesn't seem to have the same problem as the 20" models. My screen looks great, still some blacklight bleed, but no where near as bad as the first one I got. I did not notice any dead pixels on either system, but I have heard it is an issue.
 
Halo effect problem

You are experiencing what is called the Cloud Effect which is prevelant in many LCD displays. I recently purchased the Sony Bravia KDL-46V2500 Digital HD monitor and have this same problem occuring on the left side of the screen. This problem is common among LCD monitors or computer displays such as the Apple 24" Imac displays. On another note, I almost purchased the new Imac 24" black border and reflective glass front computer, but stopped short when I saw it at an apple store last week. I hated it. I was able to buy the flat screen matted 24" unit instead. I'd advise anyone doing much video edting as I do to stay away from this new version. Apple really screwed up. What were they thinking.

Henri



Just got a 24" iMac this past weekend, love it. However, I have noticed a light "Halo" at the top left part of the screen. It almost looks like the back light is bleeding over to the top of the screen. It is only visible when the top of the screen is dark or black, such as when watching a letterbox movie. They also appear along the bottom of the screen just not as bad. Has anyone else noticed this?
 
have any of you messed with the color profile yet? people say the 20" ships with a lousy profile and have posted a fix. the 24" looks good, but, when comparing color in say illustrator to what gets displayed normally - there is a huge difference on some colors.

The profile I created for my 24" is attached. It does "cool down" the display somewhat, but I thought the default profile looked a bit too yellow anyway.

To use, unzip the attachment and copy the .icc file to /Library/ColorSync/Profiles/Displays. Then open System Preferences -> Displays and select the Color tab. The profile is named iMac-Native.
 

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The profile I created for my 24" is attached. It does "cool down" the display somewhat, but I thought the default profile looked a bit too yellow anyway.

To use, unzip the attachment and copy the .icc file to /Library/ColorSync/Profiles/Displays. Then open System Preferences -> Displays and select the Color tab. The profile is named iMac-Native.

thanks! i'll give it a try.
 
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