LCD gradient test

[SaSaSushi]

And I completely agree with you. I apologize if it made me seem like I was judging every imac to have a bad screen - but only the ones I've seen personally.

This is what I meant by contradictory and was exactly what I was mainly objecting to. When you make statements to someone who reports having a good screen to the effect of "You're lucky. They're rare." it seems very much as if you're saying what you you deny saying above.

Commenting on your own personal experiences I neither have any problem with nor would I try to refute.

 

[rpeters83]

This is what I meant by contradictory and was exactly what I was mainly objecting to. When you make statements to someone who reports having a good screen to the effect of "You're lucky. They're rare." it seems very much as if you're saying what you you deny saying above.

Commenting on your own personal experiences I neither have any problem with nor would I try to refute.

Here we go again...

I said he's lucky. That's a compliment. I wish I was that lucky. Again, like I said, I was only basing it off what I've been seeing.

 

[SaSaSushi]

What sold me at compusa was the 12 months 0% interest. i also just bought a new car last month so i don't have all the money in the world at the moment.

However, I may still do that. Do they offer financing?

Well, I financed mine here in Japan but sorry I don't know what the deal is back stateside. It can't hurt to ask. I would imagine so although it may not be 0%. I wish I had that option over here! I did 10 months at about 5.3%.

It seriously sounds to me like CompUSA might just be blowing you off. Tell them there is no word of any restricted shipments on the Apple Store and I would think especially at the busy holiday season it would be huge news if there were.

 

[SaSaSushi]

Here we go again...

I said he's lucky. That's a compliment. I wish I was that lucky. Again, like I said, I was only basing it off what I've been seeing.

OK, last word on this and I hope you get it this time. It was not the "lucky" part it was the "those are rare" after it with absolutely no qualifiers like "in my experience".

You clearly insinuated that the vast majority of iMacs had gradient issues and only a rare few have good screens.

 

[rpeters83]

OK, last word on this and I hope you get it this time. It was not the "lucky" part it was the "those are rare" after it with absolutely no qualifiers like "in my experience".

You clearly insinuated that the vast majority of iMacs had gradient issues and only a rare few have good screens.

Ok. Fine. Good. Big deal. You caught my mistake. I didn't elaborate on my comment. I'll be sure to triple check what I say next time so that nothing I write may offends you.

LOL...

 

[Leon Kowalski]

Judge for yourself, I won't use the word perfect, but I will say that I am happy with the performance:

Full Screen:

It's not possible to judge from that photo -- the white areas are totally blown out at 97%-99% RGB saturation.
The blue center stripe is also blown out at 97%-99% blue saturation (plus a significant green component that's
not present in the original test pattern). At that exposure level, any information on relative brightness or color
uniformity is completely lost. Back off an f-stop or so and try again.

LK

 

[SaSaSushi]

Ok. Fine. Good. Big deal. You caught my mistake. I didn't elaborate on my comment. I'll be sure to triple check what I say next time so that nothing I write may offends you.

LOL...

You still don't get it, lending further credence to my prior observation which you called a "personal insult".

But hey, it wasn't for my lack of trying to explain things to you.

Best of luck to you, friend.

 

[czachorski]

It's not possible to judge from that photo -- the white areas are totally blown out at 97%-99% RGB saturation.
The blue center stripe is also blown out at 97%-99% blue saturation (plus a significant green component that's
not present in the original test pattern). At that exposure level, any information on relative brightness or color
uniformity is completely lost. Back off an f-stop or so and try again.

LK

That's exactly how it looks. Leon - sounds like you are "blaming the tools" - wasn't it you who said that only a poor carpenter blames his tools?

 

[czachorski]

Not the photographic expert here - all I did last night was shut out all the lights, and take the pic, letting my camera use all it's auto settings, as has usually been the specified procedure by the naysayers. Seems like every time they see something good, they try to change the rules......

I have never used the manual settings on my camera, but it has them, and I found a setting called "ISO level". Not sure how this relates to f-stops, but the manual says this will lower the camera's sensitivity to light, so I took 3 more this morning, one with auto settings, and then I dialed the ISO down to -1 and -2 (as low as it will go). Whatever those settings mean. How many ways are we going to have to slice this until some people shed this silly bias / slant??? Did the photoshop left/right side by side thing with the same result as last night (too lazy to post it, plus I think the results below are pretty clear). Here you go:

 

[Mindflux]

Yesterday, I received my new iMac (20" 2.4ghz) from shanghai bought from the apple store.

You have a 20". Your test needs to have the white on top and bottom, with the blue bar in the middle. The test above is for the 24" who have a left to right fade, 20's have a top to bottom fade.

 

[Leon Kowalski]

That's exactly how it looks.

Could be. Can't tell one way or the other based on that photo.

Leon - sounds like you are "blaming the tools" - wasn't it you who said that only a poor carpenter blames his tools?

a) None of MY tools involved.

b) It's not the camera's fault.

LK

 

[czachorski]

Could be. Can't tell one way or the other based on that photo.



a) None of MY tools involved.

b) It's not the camera's fault.

LK

Thanks for ignoring the photos I posted that meet your technique specifications, and show the same good quality of the screen. Nice.

So all camera's perfectly replicate the color, saturation, gradation present in the field? You seem like someone who knows a thing or 2 about cameras, and even I know better than that.

 

[Leon Kowalski]

... letting my camera use all it's auto settings, as has
usually been the specified procedure by the naysayers.

a) Now who is blaming whose tools?

b) I never saw any such "specified procedure." If you read the photo notes
in my 24" ALU gallery, it's obvious that they weren't auto-exposures.

http://picasaweb.google.com/TheLooby

... so I took 3 more this morning, one with auto settings, and then I dialed the ISO down
to -1 and -2 (as low as it will go). Whatever those settings mean.

The "-1 and -2" look like exposure bias rather than ISO settings -- but it's results that count.
Ya done good. the 2nd photo is fine for "passing judgement." I'll let others decide what they
think -- but I will say your photo #2 looks far better than my (ex) 24" ALU. OTOH, I think
you'll agree that it doesn't look as uniform as it did in the overexposed photo posted earlier.

...thanks for taking the time to post useful info,

LK

 

[czachorski]

but I will say your photo #2 looks far better than my (ex) 24" ALU. OTOH, I think
you'll agree that it doesn't look as uniform as it did in the overexposed photo posted earlier.

...thanks for taking the time to post useful info,

LK

The comment on the comparison to your 24" AL makes it sound like you think I am disputing that there are any bad iMacs. I totally understand there are bad ones, and feel genuinely bad for you and others that have got them. It is the general tone by you and others that all iMacs or even most iMacs have the gradient that I am taking issue with.

As far as agreeing that the it doesn't look as uniform as the one from last night - I thought it looked about the same. Here is the left/right photoshop of photo #2. It looks about the same as the one from last night to me:

And the one from last night again:

 

[Leon Kowalski]

It is the general tone by you and others that all iMacs or even most iMacs
have the gradient that I am taking issue with.

Can't speak for "all" iMacs, but I've carefully examined over a dozen first-hand, and
took light meter readings on five of them -- and they were all extremely bad. Every
one I measured had brightness non-uniformities of 2.5:1 or worse, and the others
didn't look any better. 12-out-of-12 duds (with different production dates) is pretty
good evidence that the problem is (or was) far from "rare." Maybe they're getting
better, and I truly hope they are. Your photos are much more valuable for judging
that than a bunch of fanboy "mine looks really, really great" testimonials.

Seriously, thanks again for posting them.

As far as agreeing that the it doesn't look as uniform as the one from last night -
I thought it looked about the same. Here is the left/right photoshop of photo #2.
It looks about the same as the one from last night to me:

I don't mean to be critical of your effort, but comparing the extreme right/left edges
doesn't necessarily reveal non-uniformities. My 24" ALU had an intense hotspot about
6" from the left edge of the screen; right/left edge differences were not the problem.

LK

 

[czachorski]

I only compared the extreme left/right edges, because that seems to be the most common manifestation of the gradient issue (and that's the way you did it in your comparisons in other threads ). The brightness looks uniform to me across the entire screen in real life, and in the photos, although I have not photoshopped every square inch to compare. But so far, my eyes have been fairly consistent with the PS results.

The store observations of the numerous bad Macs, is it recent? You made similar observation a few months ago, and subsequent to that, I have too, and I have seen nothing but good ones. I'm still operating under the theory that there were batches of bad ones that filled entire stores amongst the early shipped ones, and that the problem has since been reduced or fixed. That's just based on my own experience with my iMac and what I have seen in just a few stores.

 

[czachorski]

Just a quick PS -

Do you want to take bets that if I went to the Apple store near me tonight and took similar photos of the 24" iMacs in the store, that every single one would look just like mine?

Just sayin....

 

[Leon Kowalski]

Do you want to take bets that if I went to the Apple store near me tonight and took similar
photos of the 24" iMacs in the store, that every single one would look just like mine?

Just sayin....

Could be. My interest in visiting Apple stores has waned; the white 20" will be just fine
for a year or three. I seriously hope Apple is silently working on the problem, although
a more public/transparent approach would be far better for customers AND their own
long-term corporate street creds.

I only compared the extreme left/right edges, because that seems to be the most common manifestation
of the gradient issue (and that's the way you did it in your comparisons in other threads ).

Please allow me to refresh your memory:

https://forums.macrumors.com/posts/4361550/

Of course, a few posters unfamiliar with industry-standard definition of "luminance uniformity"
were critical of the fact that I followed the universally accepted practice of comparing brightest
to darkest -- rather than using arbitrarily pre-selected screen locations:

https://forums.macrumors.com/posts/4362408/


"Few things are harder to put up with than the annoyance of a good example."
- Mark Twain

.

 

[rpeters83]

Not the photographic expert here - all I did last night was shut out all the lights, and take the pic, letting my camera use all it's auto settings, as has usually been the specified procedure by the naysayers. Seems like every time they see something good, they try to change the rules......

I have never used the manual settings on my camera, but it has them, and I found a setting called "ISO level". Not sure how this relates to f-stops, but the manual says this will lower the camera's sensitivity to light, so I took 3 more this morning, one with auto settings, and then I dialed the ISO down to -1 and -2 (as low as it will go). Whatever those settings mean. How many ways are we going to have to slice this until some people shed this silly bias / slant??? Did the photoshop left/right side by side thing with the same result as last night (too lazy to post it, plus I think the results below are pretty clear). Here you go:

Yours looks just like mine. If you squint, you can sort of tell a difference in all 3 photos. However, as I'm learning with mine and by playing around with settings, it's ever so slight.

I'm actually leaning on the edge of keeping mine.

I contemplated getting a mac mini and using a monitor that i had here that was "good". turned out, when i tested it, it was complete crap and the backlight bleed was horrible. colors were also all grayed out.

granted, it was even on both sides, but it was crap compared to the 24" imac screen.

i also found out that by using a calibration that takes out some of the brown hues, it really helps it out. you can barely tell a difference on whites but on greys (like the os x title bars), you cant tell a difference as opposed to using the stock imac calibration.

i can upload it if anyone wants too to try it out.

 

[czachorski]

Yours looks just like mine. If you squint, you can sort of tell a difference in all 3 photos.

I sorry - what? Squint? I don't mean to rip on your screen, or anything, but I have to take issue with these statements. When I looked at your photo, I can see a gradient with the right side darker immediately. I just don't see a gradient like that on mine in real life, in the photos, or when I place the left and right edges side by side in photoshop.

If this is your criteria for judging screen - that a screen like mine has an issue that makes it defective, then you will never be happy with another iMac, or probably any screen for that matter. So on second thought, definitely don't go exchange it for another one. It looks like your never going to be happy.

Your screen left/right edges:

My screen left/right edges with the light sensitivity reduced per Leon's suggestion (middle photo):

 

[ceres]

Yes please upload that profile. The iMac panel per se is good. The tinting is horrible (on my machines so far).

 

[czachorski]

Yes please upload that profile. The iMac panel per se is good. The tinting is horrible (on my machines so far).

My profile? It's one of the built-in ones: Apple RGB