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who DIDN'T get a dud aluminum imac??
- Thread starter lechon
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Welcome
Welcome to the world of Mac Apples... I really hope that you both have a great experience and enjoy your new iMacs. I also have had no problems...
Enjoy
Welcome to the world of Mac Apples... I really hope that you both have a great experience and enjoy your new iMacs. I also have had no problems...
Enjoy
Professionals realize that you don't need 0.01% precision and accuracy
to analyze a 2.5x difference in brightness. The cheapest camera you can
find is more than adequate to measure differences only 1/10 that large.
Only an idiot would think you need a micrometer to make "professional"
measurements of a football field.
LK
I am going to just add to this the effects of light fraction as it passes through glass affecting the digital photo of the screen. I am no light physicist, but if I am reading this web page correctly, the light refraction going from glass to air will cause the light waves to spread apart. I'm wondering if this might cause a distortion of colors/gradients in a photo. My screen look great to me, and in the photos, I was 6 feet from the screen, reducing the effects of viewing angle and refraction. I would guess that if you took the photo with the camera closer (so the screen fills the frame of the photo) you could be introducing bias in any photo just from refraction and viewing angles.
For example, from the linked page:
This image shows the effects of light coming from behind glass and how it spreads out as it enters the air. If you are the straight on arrow, you get no refraction, but the farther from straight on, the more refraction effects. Imagine taking a photo, and what is straight in front of the camera is the regular light, and what is coming from the left and right edges of the monitor are passing through the glass at an angle to get to camera lens and are affected by light refraction.
And then as shown in this image, if I am not mistaken, as the light passes from the air to the camera lens, the refraction happens again, which would further distort the light and amplify the effects again as the light is further "spread apart".
I am no optics expert, but I know that glass has an index of refraction that is higher than even water. I'm imaging the light from the edges of the screen getting more refracted and bending the light from the edges of the screen so that less luminscence from the edge makes it to the camera than from the middle, kind of like the bending that can be seen in water in the image below. I wonder if this effect would bias the sample of using a digital photo to judge lighting consistency. It would explain why it seems that a photo would show a gradient when the user seems to perceive the screen to be good. Not sure if this is valid. Anyone with a better understanding of light refraction?
Professionals probably also prefer a device that actually displays a measurement in candelas per square meter and doesn't rely on subjective eyeball evaluations from questionable results. I am just guessing though.
Are you one of those guys that uses a screwdriver as a punch with a hammer? Sure, it can be used for that purpose with mixed results. Sometimes it even does the job. Sometimes it shatters and leave you with bloody hands. Its always a good idea to stick with the tools actually designed to do a job and not substitute.
What about noise in the image from processing? What about imperfections in the lens?
The whole damn world is crazy. When I first heard of the "gradient issue" with the iMacs I looked for it on mine. Nothing. I've used the test images and compared by putting the sides together in Photoshop, I've stared at white pictures. There's nothing wrong with it.
Have some faith. Not every iMac in the world is broken. I'll bet that some of the nay-sayers could see a gradient in a piece of white A4 paper.
Very good information. It would be quite interesting if some adventurous soul out there who has a screen showing a gradient in digital photos would be willing to pop off the glass and take a series of shots without it.
I suppose one would need to in order to make a perfectly fair comparison to the quality of the previous version iMac matte screens that Leon champions so much. The glass Is a factor when using his scientific 'patented' luminance measuring system.
The real point is of course that if you have to go to the trouble of ...making your room pitch dark, carefully setting the proper exposure settings on your digital camera and then taking the resulting photos and cutting and pasting them to match parts to even find a supposed gradient that you can NOT see with your naked eye when looking at what the camera is shooting... is there really a gradient at all??
No one will know until they take a true luminance meter and use it to properly measure their displays. Great is the power of suggestion to influence perception and a digital camera is not designed to measure luminance levels.
"Mr. All-About-The-Facts" Kowalski seems to be suffering from a terminal case of selective perception. He had a defective machine with a severe gradient that you didn't need to cut and paste to see and now he's out for vengeance, damn the facts. Now it's not a bad machine he had but a full product line defect. It's a design flaw. It's Apple getting greedy and using cheap, low quality backlights and poor engineering! You can't stop him. He's on a crusade and anyone that gets in his way or disagrees in the slightest is nothing but a fanboi, a shill for Lord Jobs.
Ooh! Now there's a news flash!
Duh! And how do ya suppose those light waves got into the glass in the first
place? Maybe -- just maybe -- they passed from air to glass? ...ya think?
A flat sheet of glass is NOT a lens. Any angular deflection on the way out
EXACTLY offsets the equal-but-opposite angular defelction that occured on
the way in. Net result: ZERO change in direction. None. Nada. Zip.
Please explain how the light rays "know" they're on the way to a camera,
rather than your eyes. When a camera appears, do those "it looks great"
light rays magically rearrange themselves in mid air (or mid glass) just
to fool the photograph? I'll bet you could really mess with their photonic
little minds by lookin' at the screen through a single lens reflex ...huh?
BTW, there are ways to "fill the frame of the photo" without getting close
to the subject. ...didya ever hear of telephoto lenses? ...or cropping?
An 8MP camera could resolve every pixel on four 24" iMacs in the same
frame, and you don't need nearly that much resolution to get an excellent
measurement of display uniformity.
Imagine having a clue about optics.
Big IF. ...huge!
Yes, of course. That's a well-known property of photographic lenses -- Canon,
Nikon, Lica, et al spend hundreds of millions of dollars perfecting techniques
for distorting and 'spreading apart' light rays. It's a huge competitive advantage
to create images that look nothing at all like the original subject.
Uh, lemme guess ...carreer employee at the Bureau Of Redundancy Department?
Hmm ... usin' photographic evidence to prove that photography doesn't work?
...can I nominate my goldfish?
LK
In response:
*Raises Hand*
Only problem is this wire coming out of the keyboard, it has taken up residence and no matter how hard I yank it, much unlike a cat's tail, it doesn't turn around, bite me, and leave......
*Raises Hand*
Only problem is this wire coming out of the keyboard, it has taken up residence and no matter how hard I yank it, much unlike a cat's tail, it doesn't turn around, bite me, and leave......
I'm not sure it's as simple as you are making it, Leon. I'm looking at the image below and noticing that while the angles are the same, the light coming out of the acrylic block is shifted to the right of where it would have otherwise been without the block. Light passing through the glass of the iMac on an edge is going to shift, where as light in the middle will not. Will this not have any effect on luminosity from the edges when taken with a photo?
And why have the camera company's spent so much money dealing with refraction on their lenses, when the lens has air on both sides of it too, and according to you, since the angles in is exactly offset by the angle going out, it seem like refraction would not be an issue there either, following your logic.
No, I am not an optics expert or a photography expert. That does not give you the right to be a condescending ass. Take a crack at enjoying the conversation and technical discussions, rather then trying to be such a jerk.
And why have the camera company's spent so much money dealing with refraction on their lenses, when the lens has air on both sides of it too, and according to you, since the angles in is exactly offset by the angle going out, it seem like refraction would not be an issue there either, following your logic.
No, I am not an optics expert or a photography expert. That does not give you the right to be a condescending ass. Take a crack at enjoying the conversation and technical discussions, rather then trying to be such a jerk.
Leon.
Did you plan on making a real point, or just insulting others?
Sure, an 8MP chip may theoretically have the resolution to photograph every pixel on a display, but it's just not going to happen in reality. A camera isn't going to be able to process the image perfectly.
As others have said, even if it did happen, having to go into such detail that you're comparing individual pixels to see any sort of difference pretty much proves that it's a non-issue. Do you use your computer through a camera zoomed in to several hundred percent? No, you look at it with your eyes, which can't see any gradient at all.
Did you plan on making a real point, or just insulting others?
Sure, an 8MP chip may theoretically have the resolution to photograph every pixel on a display, but it's just not going to happen in reality. A camera isn't going to be able to process the image perfectly.
As others have said, even if it did happen, having to go into such detail that you're comparing individual pixels to see any sort of difference pretty much proves that it's a non-issue. Do you use your computer through a camera zoomed in to several hundred percent? No, you look at it with your eyes, which can't see any gradient at all.
Originally Posted by czachorski 
I am no light physicist, but ....
When are you going to stop pretending you're the world's foremost expert on everything, Leon?
Rather than sarcastically ridicule Czachorski's honest appraisal of his own lack of expertise why don't you emulate it a little? It would certainly be refreshing.
I am no light physicist, but ....
When are you going to stop pretending you're the world's foremost expert on everything, Leon?
Rather than sarcastically ridicule Czachorski's honest appraisal of his own lack of expertise why don't you emulate it a little? It would certainly be refreshing.
Were you under the impression that Leon Kowalski is capable of making actual valid points? He's a man with an agenda.
Sometimes if you just ignore him he goes away. That's often hard to do though as I can personally attest.
You're using too much logic with him, Spook. It won't be long before you're added to his "fanboi" list where everyone who doesn't lockstep with his BS eventually ends up.
I'm disgusted with my new iMac. Apple has really dropped the ball on this one.
I have noticed that every time I drink heavily the text on the screen starts moving and dancing around. I have returned my iMac over five times now and last night, after drinking heavily, the problem returned. I have showed the iMac to my friend who, after drinking heavily, saw the same thing.
There is a serious problem with the iMac monitors that Apple just refuses to admit to. I blame the iPhone. Jobs just doesn't care.
I have noticed that every time I drink heavily the text on the screen starts moving and dancing around. I have returned my iMac over five times now and last night, after drinking heavily, the problem returned. I have showed the iMac to my friend who, after drinking heavily, saw the same thing.
There is a serious problem with the iMac monitors that Apple just refuses to admit to. I blame the iPhone. Jobs just doesn't care.
My actual iMac 2.0 is perfect, apart from the wifi issue with Leopard and my Apple base station - now that is a ludicrous situation. Any other company would've apologised for faulty equipment but Apple I guess operates on a different level. I think they should apologise AND fix the damn thing.
Yes, it will not have any effect -- other than a microscopic difference in attenuation
due to tiny differences in optical path length for rays passing through a thin glass
plate at slightly different angles. Google: Beer's Law.
Tiny path length difference * negligible optical density = micro-mouse-nuts.
Camera companies spend huge amounts of money developing high-index
glass formulations in order to MAXIMIZE refraction. That's what lenses do,
they REFRACT -- it's not a flaw, the entire freakin' goal is to BEND light.
And in case you never noticed, lenses don't have flat, parallel surfaces,
so (by design) the stuff about offsetting angles does not apply.
Window glass companies spend huge amounts of money developing processes
to manufacture absolutely flat glass plates of highly uniform thickness, in
order to MINIMIZE refraction -- the entire freakin' goal is to NOT bend light.
Your clueless "lecture" on optics deserves only mockery. If you presume to
give pompous tutorials on subjects which you (obviously) know nothing about,
you should be prepared for the consequences.
...have a blissful day,
LK
An excellent point. Thank you.
But unfortunately others I want to hear from might not choose to do the same. It's yet an imperfect science.
Plus, and this is remarkable, outside of his gradient crusade I've actually seen Leon make the occasional almost useful remark (sans his trademark sarcastic ridicule and name-calling) in some other threads. There may be hope for him yet although I highly doubt it.
I wonder if his mother even loves him. He's quite disagreeable.
You are one bad dude! I don't think ANYONE'S going to mess with you after this, Leon. Did you scratch another notch on the side of your matte-screen iMac?
So far the only thing you've won at is the battle of pejoratives.
-PLUS-
At least he's not doing something retarded like advising people to use digital cameras as luminance meters. You gotta give him that much credit anyway.There are some REALLY clueless people out there.
Cashgap was jesting as you can see he explains 3 posts further down in the thread. He was sarcastically poking fun at those who make these very suggestions. You and he (and I for that matter) are actually in perfect agreement.