Does the iPhone 4 really have Retina Display?
Apple states that the iPhone 4's 3.5-inch display has 614,400 78 micrometer-wide pixels which gives us a density of 326 ppi (pixels per inch). Apple claims this will give the iPhone 4 a, "pixel density so high that the human eye is unable to distinguish individual pixels" (at 12 inches). So, is this just a bit of marketing magic or does the iPhone 4 display really venture beyond the limits of the human eye?
Raymond Soneira, the president of DisplayMate, a company which does analysis of screens gave these statistics: the angular resolution of the retina is 0.6 arc minutes per pixel, which he derived from the angular measure of 50 cycles per degree with each cycle being a line pair -- two pixels.
Using this model if you hold an iPhone 4 at 8 inches you would be viewing 716 ppi, at 12 inches it would be 477 ppi and if you hold an iPhone 4 further away at 18 inches it would then fall to 318 ppi. From this Raymond Soneira deduced that the iPhone has significantly lower resolution than the retina. He even went further stating that you would need a resolution higher than the retina to deliver a image that looks perfect.
William H.A. Beaudot, Ph.D, a researcher from McGill University, states in his profile that "My research is aimed at understanding how visual information is integrated across space, time and its attributes by the human visual system, as well as modeling specific anatomical circuits and interactions between the visual cortical areas involved in these processes." You got all that? Me neither... but he seems to know a lot about the visual system.
Beaudot states that 300 pixels per inch is related to standard visual acuity of 20/20 vision. This means that a normal eye can discriminate between two points by 1 arc minute (1/60 deg). 1 arc minute seen from a distance of 12 inches to a dot size of about 89 micrometer or pixel density of 286.5 dpi. Thus, since the iPhones retina display has a pixel density or 326 dpi, it is 14 % better than we would have at 12 inches with 20/20 vision. Using these facts Beaudot feels that Apples claims are accurate.
He went on to state that the optimal viewing distance quoted by Jobs is 12-inches but Beaudot feels that this may be too close. He measured that the most comfortable distance from his eye to the iPhone 3GS was 18 inches which would make Apple's numbers even better.
So what does seem to be agreed upon is that from 12 to 18 inches the image will be pretty close to if not better than visual acuity.The 326 dpi of the iPhone 4 is also better than magazine print which is only 300 dpi. If you are one of the few who hold your iPhone within 5 inches of your face you will probably be able to see pixels. Either way the iPhone 4 will have a display unmatched in the smartphone market.
What do you think about this, I would love to know your opinion.
[The Loop, Gadget Lab, Popular Mechanics via Gizmodo]
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Senior Editor at iMore and a practicing therapist specializing in stress and anxiety. She speaks everywhere from conferences to corporations, co-host of Vector and Isometric podcasts, follow her on Twitter @Georgia_Dow and check out her series at anxiety-videos.com.
For now the iphone 4's new "retina display" will do just fine. Even if the name does suck.
Regardless of visible pixel structure, I haven't heard anything but glowing reports from those lucky people that have seen it.
how have you seen the display?
Average user holds their iPhone appox 12inches away, 18inches or 5inches away is a lot less likely.
Apple just can't lie and say That they have incorporated retina display technology when they really haven't. That's false advertisement.
Dots per inch of display does not change with distance.
Dots per inch on the Retina does.
Maybe thats a "Well DUH" for some of you, but it confused me till I followed links in some of the Giz articles.
So any improvments are welcome.
Phil Plat provides additional balance to the argument, of course balance doesn't really matter in the modern internet culture.
Secondly, very few people have 20/20 vision, and that's not perfect human vision anyway! Perfect human vision may be able to discern pixels from 12" away, but honestly I highly doubt it!
Films already look great on the 3gs itself - what I want to know is if this improved resolution will translate to better output to a TV.
Good job Georgia!
@SteveWoz - Leave troll.
You are so true with all these smartphones with their numbing specs: blazing processors, space age screens resolution, camera's, video games, etc........
Did we forget somewhere down the line that this is a PHONE!
I love my iPhone and can't wait to get iPhone 4. But I hope the new design will help dropped calls. I live in downtown Minneapolis and I get a lot of dropped calls. When I lived in Atlanta i did not have this problem. I am hoping that the iPhone 4 new antenna will help with that. I do get fast 3 g here though that's for sure.
My job is getting us the evo (which I really don't like) but the 4g speeds are ridiculous. They have a 4g tower on top of the holiday inn near the metrodome. I hope ATT hits the 7.2 hdspa switch soon. I want faster speed.
Everyone was cited and I thought I did a pretty good job actually but each to their own =)
1. I assume people wear glasses and contacts to bring their vision up to 20/20.
2. I also assume that most people who don't have 20/20 vision use contacts and glasses daily.
If those assumptions are correct, then saying that the new iPhone truly DOES have a retina display to the majority of the population isn't correct.
Glasses off, retina display.
Glasses on, really nice display.
Like has been said, "retina display" is a branding and marketing scheme. Is Apple advertising capabilities of the LCD in the iPhone 4 that are untrue? Well, it's complicated. It's a fairly simple give and take between pixel density, visual acuity and distance. The only thing fixed is the pixel density at 326 dpi. The rest, one's visual acuity and eye-distance from the phone is highly variable. And this is all assuming high contrast black and white eye chart images. If its color, it's pretty much game over as human vision suck at color.
For all intents and purposes, that is, for all typical uses, the user will not be able to discern the pixels. The iPhone OS will not be displaying easily discernible high contrast images for basically all cases. Black-on-white text will have decent contrast ratio, if the 800:1 contrast is true, but it isn't eye chart good. For 99.9% of the stuff on the screen, I don't think it'll be discernible with the scale-distance as described: 20/20 vision at 12 inches. If one is 20/15, it'll be 18 inches. If it is 20/10, then you're a genetic mutant with bird eyes and shouldn't be called human. ;)
It is amazing that nerd-OCD only seems to target Apple though. Well it's likely "Apple" is a click-monster so we hear everyone about Apple and everything else is drowned out: The Nexus 1 and Droid Incredible 800x480 AMOLED screen. Is it false marketing when the AMOLED screen on these devices uses a PenTile sub-pixel arrangement, resulting in a third less sub-pixels and a who knows how much less color space? The HTC EVO 4G thickness is specified at 0.5 inches on the HTC website. I do not believe this includes the camera. This is a trick played by basically everyone. For awhile, PC laptop vendors were advertising the thinness part of the laptop as the "thickness." False marketing? Weight. For awhile, laptop vendors were advertising some "low" weights by not including things like the battery or optical drive. False marketing? Weight, dimensions, and even screen size are fundamental aspects of gadgets. Yet, the gadget sites never validate the advertised specifications. I guarantee to you that some website will test the iPhone's "Retina Display" by putting it through the ringer with various visual acuity testing. That's Apple unique as their brand power is huge. But a gadget site actually testing the weight, size, and dimensions of devices they review and test? Never. I'm interested in seeing it dawn on them that many "technical specifications" are marketing numbers. Everyone does it.
Screen size is one of those things that really irk me too. The Droid's 3.7" display is actually only 3% larger than the iPhone at 3.5" inches even though 3.7/3.5 is 6% larger. You see, screen size should be measured in area, not linear "diagonal" distance. For example, the iPad's 9.7" display is actually 2% larger than a 10.1" 1024x600 display that is mostly standard on netbooks. Yet, here we are where we are left with the impression that a 10.1" netbook screen is larger than an iPad screen.
Bah, most of you guys don't really know what technical correctness is, and you are just arguing the merits of brand of advertising.
Off to heat up a frozen crow dinner...