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Uneveness? Glossyness? Dead Pixels?

Leon Kowalski said:
I am not aware of any correlation between visual acuity an intelligence.
Click to expand...

What is the correlation between denying visual evidence and intelligence, Leon?

I also posted: "For more/larger ... photos ... see: http://picasaweb.google.com/TheLooby "

And thus, mine is more than twice as big as yours.
My photos are larger, too.
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Here is a link to my original, unedited photo at 3702x2304 pixels. Now I'm twice as big as you again.

http://www.ito-giken.com/24alumimaclarge.jpg

What "I see" is subject to carbon-unit frailities and bias...
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Whatever the heck that means. Too bad we were talking about your supposed left to right gradient of 2.51 to 1 in EVERY single 24" Aluminum iMac. Stay on topic, please.

...why not ask Mr. DigitalColorMeter.app ?

LK
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I'm not exactly sure how relevant mouseover readings with Digital Color Meter of a digital photo, no matter what resolution the photo is taken at, are going to be to the actual luminance of the display in question. That said, the photos are posted so knock yourself out.

Trust your eyes, Leon. I've seen the photos you posted and that radical gradient is not present in my display. If I had a luminance meter I might take an actual measurement for you but I do not.

Actually, at this point I'm not really sure why I'm bothering to continue jumping through your hoops at all. Stupid me indeed.

Here's another shot of my display:

24alumimacfront2.jpg
 
Leon Kowalski said:
I am not aware of any correlation between visual acuity an intelligence.



I also posted: "For more/larger ... photos ... see: http://picasaweb.google.com/TheLooby "

And thus, mine is more than twice as big as yours.
My photos are larger, too.



What "I see" is subject to carbon-unit frailities and bias...

...why not ask Mr. DigitalColorMeter.app ?

LK
Click to expand...

Your last sentiment was "does no one with a good iMac screen have a camera?" That seemed pretty strong. Now upon overwhelming photographic evidence, your sentiment seems to have changed to "does no one with a good iMac screen have a luminance meter?" That seems pretty weak.
 
This is just like the MBP threads Leon. A few people end up with slightly faulty displays or the lighting in their room is terrible or their eyes are seeing something that isn't there and they assume that all of the iMacs or every Apple product is faulty.

There is obviously not as much of a problem as you and the others make it out to be. You have had faulty screens, two of them maybe, but there isn't a wide spread disease of poor 20" and 24" iMac displays. If the big three (CNET, New York Times, and MacWorld) don't say much about this imaginary problem then it's probably not as bad as the few people are making it out to be.
 
Leon - I took a screen shot of your grey gradient and put it side by side with Sushi's. Your is plain as day, and Sushi's is hard to even see.

Furthermore, I had to rotate your to put them side by side. Why would that be? Because Sushi's is a vertical gradient. I thought the 24" iMacs had this problem from left to right? Hmmmm. Or could it be, that the slight gradient in Suchi's photos is an artifact from the camera angle, flash, room lights, etc?

Or are you now claiming a vertical gradient/brightness problem exists on 24" iMac? Because if you are, you are the only one. I don't see this complaint anywhere else on the web.

alum_imac3.jpg
 
czachorski said:
Furthermore, I had to rotate your to put them side by side. Why would that be? Because Sushi's is a vertical gradient.
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You entirely missed the point. The screen grabs I posted are samples from the left and right side of the SAME screen photo. Any vertical gradients within the individual samples are trivial compared to the brightness difference between the left and right sides of the screen. (You can see where the left-hand sample came from by noting the position of Sushi's mouse pointer in the original photo.)

Yes, Sushi's screen is somewhaat less ugly than my 24" ALU, (I'm happy for him), but it's FAR worse than the previous generation (20" or 24") iMacs. At the very best, it's on the raggedy edge of meeting the absolute minimum luminance uniformity requirements of widely accepted international ergonomic standards, such as TCO'03. ( http://www.tcodevelopment.com )

...I'd grade it a high F+

LK
 
Leon Kowalski said:
You entirely missed the point. The screen grabs I posted are samples from the left and right side of the SAME screen photo. Any vertical gradients within the individual samples are trivial compared to the brightness difference between the left and right sides of the screen. (You can see where the left-hand sample came from by noting the position of Sushi's mouse pointer in the original photo.)

Yes, Sushi's screen is somewhaat less ugly than my 24" ALU, (I'm happy for him), but it's FAR worse than the previous generation (20" or 24") iMacs. At the very best, it's on the raggedy edge of meeting the absolute minimum luminance uniformity requirements of widely accepted international ergonomic standards, such as TCO'03. ( http://www.tcodevelopment.com )

...I'd grade it a high F+

LK
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So why did you take the left sample from the lower part of the screen, and the right sample from the top?
 
If the vertical variation is a function of other factors with the photo besides the screen, then it biases the comparison when you take the sample from different vertical positions. Here are two unbiased samples side by side. The top one is a full vertical sample from Sushi's screen on the left edge and right edge. The second one is the same sample from your white iMac screenshots on your posted photo page. They both look similar to me - both are lighter on one side.

If your white iMac looks perfect to you, and has this color issue in the photo, then isn't possible, just maybe, that Sushi's 24" alum iMac is perfect too, and any irregularities in the photo are caused by the photo method, just like the photos of your white iMac?


Sushi's 24" alum:

alum_imac4.jpg





Leon's white iMac:

alum_imac5.jpg
 
I ran some tests on my 20" alum Apple Cinema Display. This display is perfect in every way, and even it shows a gradient in a photo of a grey screen. I am starting to wonder if what you have really discovered, Leon, is some limitation of a digital camera CCD to accurately capture a solid color from an LCD screen photo. Here are the shots:

My 20" ACD screen photo with solid grey background:

acd1.jpg




Parsed to put left edge next to right edge:

acd4.jpg




My 20" ACD with a normal-use photo. Note that now appears to be no gradient:

acd2.jpg




Same normal-use screen from off-angle. Looks perfect.

acd3.jpg




Parsed to put left edge and right edge right next to each other. Gee - that blue sky looks identical.

acd6.jpg





I think a bias is being introduced into the method of capturing the image. We have 3 screens and 3 users all saying their screen look perfect (my 20" ACD, Sushi's 24" alum iMac, and Leon's "upgraded" white iMac). Yet all 3 screens show a gradient on a solid grey background when photographed. I think it is time to rule out the screen as the cause, and time to start questioning the photo.
 
czachorski said:
So why did you take the left sample from the lower part of the screen, and the right sample from the top?
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Luminance uniformity is specified without respect to screen position. Some non-fanboys might be less than pleased with a screen covered in black and white polka-dots, but I don't think polka-dots would qualify as a "gradient."

czachorski said:
I ran some tests on my 20" alum Apple Cinema Display. This display is perfect in every way, and even it shows a gradient in a photo of a grey screen.
Click to expand...
Nothing made by man is "perfect," but I didn't invite that straw man to the party -- you fanboys did.

Your Cinema Display has a some minor luminance non-uniformities. While it appears to be slightly less uniform than my white 20" iMac, it's still well within specs. Apple specifies the ACDs as TCO'03 compliant (just like the $179.99 econo-model 20" monitors on newegg.com). TCO'03 sets minimum requirements for LCD luminance uniformity, and specifies the methods for measuring display quality. "Looks good to me" is not currently an approved TCO test procedure.

I am starting to wonder if what you have really discovered, Leon, is some limitation of a digital camera CCD to accurately capture a solid color from an LCD screen photo.
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An poor workman always blames his tools. Before slandering your camera's manfacturer, mebby you should take another photo or two -- with the camera in portrait orientation and/or upside down. (It's also a good idea to select a shutter speed several times slower than the display refresh rate.)

Did anything change?

We have 3 screens and 3 users all saying their screen look perfect (my 20" ACD, Sushi's 24" alum iMac, and Leon's "upgraded" white iMac).
Click to expand...
There's no such thing as "perfect" -- there are only varying degrees of imperfection. In engineering, we often measure these imperfections, and then classify them -- using highly sophisticated technical terms....

...such as "big" and "little"

LK
 
Leon Kowalski said:
Luminance uniformity is specified without respect to screen position. Some non-fanboys might be less than pleased with a screen covered in black and white polka-dots, but I don't think polka-dots qualify as a "gradient."


Nothing made by man is "perfect," but I didn't invite that straw man to the party -- you fanboys did.

Your Cinema Display has a some minor luminance non-uniformities. While it appears to be slightly less uniform than my white 20" iMac, it's still well within specs. Apple specifies the ACDs as TCO'03-certified (just like the $179.99 econo-model 20" monitors on newegg.com). TCO'03 sets minimum requirements for LCD luminance uniformity, and specifies the methods for measuring display quality. "Looks good to me" is not currently an approved TCO test procedure.


An poor workman always blames his tools. Before slandering your camera's manfacturer, mebby you should take another photo or two -- with the camera in portrait orientation and/or upside down. Did anything change?


There's no such thing as "perfect" -- there are only varying degrees of imperfection. In engineering, we often measure these imperfections, and then classify them -- using highly sophisticated technical terms....

...such as "big" and "little"

LK
Click to expand...

You are spinning yourself into circles now. You wanted photographic evidence of a good working iMac. Sushi provided just that. You made a post claiming it still had a gradient. When it was shown to be working just as good as your own white iMac, and my ACD, you are now claiming that there is no such thing as "perfect". So you have changed what you are looking for again. Now it seems you want evidence of a perfectly working alum iMac, when you ackowledge that none will exist. With all this spinning, you must be getting dizzy.

Adjusting the orientation of the camera is good idea for a control show. I'll give it a whirl.
 
SaSaSushi said:
Whatever the heck that means. Too bad we were talking about your supposed left to right gradient of 2.51 to 1 in EVERY single 24" Aluminum iMac. Stay on topic, please.
Click to expand...

I can confirm that this isn't an issue on all iMacs. In fact only one of the four I've had showed this extreme gradient from left to right. The other three has had the backlighting issue in the middle, just like on yours.

However, this isn't simply a difference in brightness, there's something with the backlighting that is causing the screen to have a yellow tint. This is more annoying than uneven brightness in my opinion. It makes the screen look dirty, and one color tone appears very different in different parts of the screen. Very annoying when doing graphics work.

I guess I should thank you for once again confirming that the yellow tint issue exist on pretty much every iMac.
 
Leon Kowalski said:
Sorry, bubba, it WAS NOT shown to be "as good as" your ACD or my white iMac. It WAS shown to be measurably less uniform than either of the other two displays. Several times less uniform.

...please review my tutorial on "big" and "little"

LK
Click to expand...

Now you are showing us the real extent of the fantasy land you are living in. You've posted no measurements of the uniformity here of my ACD or your white iMac, and now you are making claims on that basis.

The side by side comparisons of the left and right side of all 3 machines shows very similar performance on a grey screen, and even gives your white iMac some advantage because it's grey is a darker, less revealing shade. On a blue sky image, my ACD shows zero variation in uniformity, and I suspect your and Sushi's would too. And yet you insist, in the face of overwhelming logic and reason, that Sushi's machine has to be worst.

You are so biased and determined for all iMacs to be flawed that you can't even see the flaws in your own logic. Sad indeed.
 
To kill this issue once and for all.

There is nothing wrong with the current iMac screens (both 20 & 24 inch) that wasn't already in the previous edition of the iMac. The screen is just fine for more than 90% of the users.

I think the users that are having problems should try to calm down a bit and look at it from the other perspective, we know you're upset but there isn't a mass influx of irregular screens being introduced into the market by Apple right now. It may be the luck of the draw, it may have been a bad batch in your area, but there isn't a massive problem that should turn you and other away from getting an iMac. Besides, Apple doesn't make the monitors, other companies like LG and Samsung do, so it's really their problem. And I am very sure that Apple engineers are putting the foots up LG and Samsung's @$$es to get the monitors straightened out.
 
Digital Skunk said:
Besides, Apple doesn't make the monitors, other companies like LG and Samsung do, so it's really their problem.
Click to expand...

To me as a costumer it's not the panel makers fault, it's Apples fault. They chose the panel, and they are responsible.
Besides, I actually think this is an issue with the implementation and not the panel itself. It might very well have to do with the backlight inverter.

So putting the blame on LG-Philips isn't really fair unless you know that it's actually their fault. And even then, the costumer can rightfully blame Apple for choosing a manufacturer who can't deliver consistent quality.
 
rainydays said:
To me as a costumer it's not the panel makers fault, it's Apples fault. They chose the panel, and they are responsible.
Besides, I actually think this is an issue with the implementation and not the panel itself. It might very well have to do with the backlight inverter.

So putting the blame on LG-Philips isn't really fair unless you know that it's actually their fault. And even then, the costumer can rightfully blame Apple for choosing a manufacturer who can't deliver consistent quality.
Click to expand...

Clearly, the blame for any screen issues lie with Apple. They are the sole and only party you conducted a transaction with.

It seems that a lot of iMacs are surfacing that are working well (at least as well as the Apple Cinema Displays (see above). I would hope that people's luck starts to improve and the problems dissipate even further.
 
czachorski said:
You've posted no measurements of the uniformity here of my ACD or your white iMac, and now you are making claims on that basis..
Click to expand...
I made the measurements, and...

- I posted the measurements for my white 20".

- I posted that your ACD measures less uniform than mine, but is still within TCO'03 spec.

- I posted that Sushi's 24" measures several times less uniform than either your ACD or my white 20"

- I posted that Sushi's display measures on the raggedy-edge of TCO'03 minimum requirements.

- I posted a link to the TCO. Hint: You might find the TCO'03 minimum requirements there.

You have the photos, you have the measurement tool (DigitalColor Meter.app). Now quit whining, and go measure the photos yourself -- then come back and refute my measurements, if you can.

..."looks good to me" is NOT a measurement,

LK
 
Leon Kowalski said:
I made the measurements, and...

- I posted the measurements for my white 20".

- I posted that your ACD measures less uniform than mine, but is still within TCO'03 spec.

- I posted that Sushi's 24" measures several times less uniform than either your ACD or my white 20"

- I posted that Sushi's display measures on the raggedy-edge of TCO'03 minimum requirements.

- I posted a link to the TCO. Hint: You might find the TCO'03 minimum requirements there.

You have the photos, you have the measurement tool (DigitalColor Meter.app). Now quit whining, and go measure the photos yourself -- then come back and refute my measurements, if you can.

..."looks good to me" is NOT a measurement,

LK
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Are you word smithing, or did I miss your post with the measurements?

Edit: I checked - I did not miss them - you never posted them. Why not? You must be getting desperate to spin that hard. So "looks good to me" is not a valid measurement, but posting "about them" instead of actually posting them is ok? What a hypochrite. Get real please.

You are not posting them, because you know you can't show they are 250% off like you claim, and that will sink your whole flawed contention. Too funny. And you referenced engineering earlier? What a joke. More like talking heads on the spinning news.
 
Digital Skunk said:
To kill this issue once and for all.
Click to expand...
Yeah, right!

There is nothing wrong with the current iMac screens (both 20 & 24 inch) that wasn't already in the previous edition of the iMac.
Click to expand...
Simply NOT true, especially for the 20". It is indisputably a major downgrade from the previous 20" iMac. (More details below.)

Besides, Apple doesn't make the monitors, other companies like LG and Samsung do...
Click to expand...
WRONG! No more Samsung iMacs. The ALU 20" iMacs dropped the (very fine) Samsung LTM201M1 8-bit, S-VPA panel and replaced it with the LG.Philips LM201WE3 TN-film, 6-bit, POS. Then, heaping insult on injury, they totally FUBAR'd the implementation. Bar none, it is THE worst-quality LCD panel (of any type) that I have ever seen. (And I've been a software engineer since long before Apple or MS existed. My first 'display' was a deck of Hollerith cards.)

LK


"Get your facts first, and then you can distort them as much as you please."
- Mark Twain
.
 
rainydays said:
I can confirm that this isn't an issue on all iMacs. In fact only one of the four I've had showed this extreme gradient from left to right. The other three has had the backlighting issue in the middle, just like on yours.

However, this isn't simply a difference in brightness, there's something with the backlighting that is causing the screen to have a yellow tint. This is more annoying than uneven brightness in my opinion. It makes the screen look dirty, and one color tone appears very different in different parts of the screen. Very annoying when doing graphics work.

I guess I should thank you for once again confirming that the yellow tint issue exist on pretty much every iMac.
Click to expand...

I didn't think I was color blind but clearly I must be because I don't see the yellow tint thing. The page I am typing this on right now looks crisp white and blue on all parts of the screen. I'm not seeing a "dirty" image although I suppose if you were standing beside me you might say you did since you see a yellow tint on my photo that I don't.

However, I will accept your gratitude nonetheless and appreciate your acknowledgement that in fact my display does NOT have this so-called "universal" left-to-right gradient issue.

Best of luck to you in finding a display to your own liking.

I love my aluminum iMac. I have no complaints.
 
czachorski said:
I am starting to wonder if what you have really discovered, Leon, is some limitation of a digital camera CCD to accurately capture a solid color from an LCD screen photo. Here are the shots:
Click to expand...

This is what I was saying. You cannot substitute Digital Color meter on a digital photo for the work of a luminance meter. There are so many variables that can affect the way a display appears in a photo. You'd think someone as exacting and knowledgeable as Leon might understand this.

At best it is a good way to eyeball any obvious defects like the radical gradient in Leon's own screen shots.

Let's just accept the fact that he's an annoying loudmouthed troll and try to ignore him at this point. I doubt he will go away but it serves no purpose to go in circles with him.
 
Digital Skunk said:
To kill this issue once and for all.

There is nothing wrong with the current iMac screens (both 20 & 24 inch) that wasn't already in the previous edition of the iMac. The screen is just fine for more than 90% of the users.
Click to expand...

Agreed and I think 90% is conservative. It's probably more like 99%.
 
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