# Apple's iPhone 4 "Retina" display claims spark controversy

Posts: 1,472member
Quote:
Originally Posted by Stevie

Are you sure about that? I have used 600 dpi printers since the late 1980's, and I can easily see the dots with my naked eye.

the dots printed by a printer are not analogous to pixels on a screen.
Posts: 157member
Quote:
Originally Posted by EauVive

The angular resolution of the eye is 1', that is to say 1 mm at 3 m (or 100 km on the Moon).

A 300 dpi display means each pixel is 25.4/300 = 84.7 µm.

So this corresponds to the angular resolution of the eye at 3 * 0.0847 = 0.254 m or 25.4 cm (10 ").

FWIW, I'm in my last year of college and have had some optics related courses, and I back up these numbers!

Sounds about right. Then again, you have to take into account the vision of the person, but for the normal human being, even with a 20/20 vision, the 1' is the angular resolution is correct.
Posts: 6,757member
Makes no difference what you call it or what marketing terms are thrown around, the new display is gorgeous. That's all that matters.
Posts: 25,726member
Quote:
Originally Posted by Stevie

Steve is the one who made the 12 inch claim.

Did Steve specifically state that a human eye with 20/10 vision can't determine pixels or he did he make a blanket statement that works with those with 20/20 vision or worse, which accounts for most of the population?

Quote:
Originally Posted by Stevie

I don't think so.

"Soneira claims that the actual distinguishable resolution of the human retina is 477 ppi at a distance of 12 inches. "

ISTM that this is a matter of fact and not opinion.

So your claim is that ALL human eyes are capable of distinguishing the same exact data. You are saying that these "scientists" that say that 20/20 and 20/10 vision are all full of crap.

Of course you aren't but since I clearly made a point to reference 20/20 vision and you clearly made a point to reference no variation in vision you MUST be arguing what is said in the paragraph above.

Did you even read this article that clearly explains it are you just so hell bent in trying to find something negative against Apple and Jobs to hold to?
Posts: 237member
Quote:
Originally Posted by shubidua

FWIW, I'm in my last year of college and have had some optics related courses, and I back up these numbers!

Sounds about right. Then again, you have to take into account the vision of the person, but for the normal human being, even with a 20/20 vision, the 1' is the angular resolution is correct.

No wonder I extracted the figure from my neurophysiology book.

In France, we measure the visual acuteness in tenths, not twentieths. 10/10, or 20/20 in the US, corresponds to 1' of eye angular resolution, but it is by no way a physiological limit: it's a mean value. Some people (I do, and many plane pilots, especially in the army, do also) reach 12/10 or more. It just means we do have a cone density on the fovea higher than normal, so we are able to make out "finer grains".

It seems also that some women have a fourth type of cone, beyond the normal ones (sensitive to red, blue, green), that would react to the orange part of the spectrum: they are called tetrachromats.
Posts: 25,726member
Quote:
Originally Posted by EauVive

It seems also that some women have a fourth type of cone, beyond the normal ones (sensitive to red, blue, green), that would react to the orange part of the spectrum: they are called tetrachromats.

I've certainly learned things in this thread: http://en.wikipedia.org/wiki/Tetrach..._tetrachromats
Posts: 25,726member
If you are watching the World Cup there is a very clear example of pixelation on the ad banners surrounding the field. How big are those LEDs, a half-inch?
Posts: 564member
Quote:
Originally Posted by solipsism

If you are watching the World Cup there is a very clear example of pixelation on the ad banners surrounding the field. How big are those LEDs, a half-inch?

Clearly you are not holding the banner 12-14" from your face.
Posts: 1,114member
This has been an interesting discussion from an ophthalmological standpoint, but is probably meaningless for real world iPhone customers. Retina Display? A catchy marketing gambit.

Another of my recent favorites is the TV commercial for a nonprescription male enhancement pill that steals the line from Viagra and Cialis. "Get immediate medical help for an erection lasting more than four hours."

The implication, obviously, is that if some poor limp stooge of a customer uses this stuff, he's liable to get a heroic stiffy.
Posts: 557member
Quote:
Originally Posted by 2 cents

Yawn.

exactly. Holy mother is this really that huge a deal?

Show me a computer maker who hasn't maybe stretched the truth a little, or boasted a wee bit.

My 3G screen looks snazzy, still. If the 4G is way better, cool. Next?
Posts: 837member
I think it's entirely appropriate for Jobs' claim to be examined for its accuracy. Jobs should have been a little more precise in spelling out what his claims are for the display. Had Jobs specified that for someone with 20/20 vision, the display did have enough resolution to do the trick, all of this would have been perfectly fine. Jobs did make a claim that is misleading, though for most of us not in a significant fashion.

It's like we know that human hearing is capable of 20 hz to 20,000 Hz but as has been pointed out, many of us, as we age, can't come anywhere close to 20,000 Hz. My limit is closer to 14,000 Hz. That doesn't mean that I can't appreciate a fine piece of stereo equipment. But it's not about the equipment's range as it is about the quality of the sound in other regards. Still, I think that it would be misleading to market a stereo with a range of let's say 30 hz to 16000 Hz as providing a range that reaches the limits of human hearing. Sure for me personally and many others, it would be in effect accurate to say that the stereo covered enough spectrum to get the job done but that's beside the point.

Still, I do imagine that pushing for even more resolution on a mobile device screen is pretty much a pointless exercise and I suppose that's the message Jobs was trying to deliver. It's unfortunate, though, that he was so cavalier about how he presented that message, making a statement that was, in truth, not accurate.
Posts: 10,473member
Quote:
Originally Posted by EauVive

t seems also that some women have a fourth type of cone, beyond the normal ones (sensitive to red, blue, green), that would react to the orange part of the spectrum: they are called tetrachromats.

Of course. That's how they see things that aren't there-my ex-wife must have been a tetrachromat.
Posts: 956member
Quote:
Originally Posted by solipsism

Did Steve specifically state that a human eye with 20/10 vision can't determine pixels or he did he make a blanket statement that works with those with 20/20 vision or worse, which accounts for most of the population?

Here's what he said:

?It turns out there?s a magic number right around 300 pixels per inch, that when you hold something around to 10 to 12 inches away from your eyes, is the limit of the human retina to differentiate the pixels,? Jobs said.

I dunno if he is correct or incorrect.

Here's what the other guy said:

"Steve Jobs claimed that the iPhone 4 has a resolution higher than the retina - that's not right:

1. The resolution of the retina is in angular measure - it's 50 Cycles Per Degree. A cycle is a line pair, which is two pixels, so the angular resolution of the eye is 0.6 arc minutes per pixel.

2. So if you hold an iPhone at the typical 12 inches from your eyes, that works out to 477 pixels per inch. At 8 inches it's 716 ppi. You have to hold it out 18 inches before it falls to 318 ppi."

I dunno if he is correct or incorrect.

But as I said (and you dispute?), this is a matter of fact, and not opinion.
Posts: 10,473member
Quote:
Originally Posted by Carmissimo

t's like we know that human hearing is capable of 20 hz to 20,000 Hz but as has been pointed out, many of us, as we age, can't come anywhere close to 20,000 Hz. My limit is closer to 14,000 Hz. That doesn't mean that I can't appreciate a fine piece of stereo equipment. But it's not about the equipment's range as it is about the quality of the sound in other regards. Still, I think that it would be misleading to market a stereo with a range of let's say 30 hz to 16000 Hz as providing a range that reaches the limits of human hearing.

Let's use your example. Typically, 20 Hz to 20,000 Hz is considered the range of human hearing. But there are a few people who can hear beyond that. I have a friend who can hear to about 24,000 Hz (probably not any more, but when he was in his 20's). So is it false to say that 20 Hz to 20,000 Hz is the range of human hearing? Of course not. The word 'typical' or 'normal' is assumed.

Similarly, for normal human vision (considered to be 20/20 by definition), the iPhone 4.0's display exceeds the ability of the eye to distinguish. The fact that there are a few people with better eyes doesn't change that.
Posts: 956member
Quote:
Originally Posted by jragosta

Similarly, for normal human vision (considered to be 20/20 by definition), the iPhone 4.0's display exceeds the ability of the eye to distinguish. The fact that there are a few people with better eyes doesn't change that.

You might be misunderstanding the controversy.

For normal human vision, as you define it, the iPhone does NOT exceed the ability of the eye to distinguish, according to vision experts.

That is the whole point of why people are commenting on the situation.
Posts: 25,726member
Quote:
Originally Posted by Carmissimo

I think it's entirely appropriate for Jobs' claim to be examined for its accuracy. Jobs should have been a little more precise in spelling out what his claims are for the display. Had Jobs specified that for someone with 20/20 vision, the display did have enough resolution to do the trick, all of this would have been perfectly fine. Jobs did make a claim that is misleading, though for most of us not in a significant fashion.

Does a presentation designed to advertise a product have to be so precise that he needs to qualify all marketing statements? I don't think so.

From what I read, it appears that only 35% of the world's population even have 20/20 vision or better. And since 20/20 is still within the threshold of arc minute from 12" away and is widely considered the "average" good eyesight I have to say that his comments are in order. What percentage of the world's population would fall under the "I can differentiate a pixel at 12 inches" category? 25%?
Posts: 956member
Quote:
Originally Posted by solipsism

From what I read, it appears that only 35% of the world's population even have 20/20 vision or better. And since 20/20 is still within the threshold of arc minute from 12" away and is widely considered the "average" good eyesight I have to say that his comments are in order. What percentage of the world's population would fall under the "I can differentiate a pixel at 12 inches" category? 25%?

Here are the good Doctor's comments on that topic:

"If you allow poor vision to enter into the specs then any display becomes a retina display. That turns it into a meaningless concept that will be exploited by everyone. The iPhone 3GS is a retina display too for good percentage of the population.

Specs need to be objective, precise and accurate. Allowing puffery and exaggerations in the sales and marketing starts a snowballing effect that eventually leads to the 1000% rampant spec abuse that I document for many other displays."

I wonder what percentage of the world's population can hear 20-20,000 Hz? Do we nevertheless use that as the spec for a reason?
Posts: 25,726member
Quote:
Originally Posted by Stevie

For normal human vision, as you define it, the iPhone does NOT exceed the ability of the eye to distinguish, according to vision experts.

Sure it does. The "norm" is worse than 20/20 and you'd have to be better somewhat better than 20/20 to even see the pixels at 12" away.

If you actually read the posts on this thread you'd see that it's been proven over and over that Soneira is the one exaggerating by taking the highest category of visual acuity, which you are foolishly attributing as the "average" user's eyesight. If you can't see that then you should get your eyes check out.
Posts: 25,726member
Quote:
Originally Posted by Stevie

Here are the good Doctor's comments on that topic:

"If you allow poor vision to enter into the specs then any display becomes a retina display. That turns it into a meaningless concept that will be exploited by everyone. The iPhone 3GS is a retina display too for good percentage of the population.

So now 20/20 is poor vision?
Posts: 10,473member
Quote:
Originally Posted by Stevie

You might be misunderstanding the controversy.

For normal human vision, as you define it, the iPhone does NOT exceed the ability of the eye to distinguish, according to vision experts.

That is the whole point of why people are commenting on the situation.

No, you're distorting things - as usual.

The doctors agree, that for 20/20 vision (which is BY DEFINITION normal) resolution is 1 arc-minute - which is about what the iPhone 4 provides at normal viewing distances.

You're confusing theoretical RETINA resolution - which is meaningless. Most people's vision has to go through lenses, the aqueous humor, vitreous humor, and cornea, before it gets to the retina. For NORMAL (by definition) vision, Jobs was correct.