For Normals, Jobs' "Retina Display" Claim May Be Fair After All 386
The Bad Astronomer writes "AT WWDC, Steve Jobs claimed that the iPhone 4's display has about the same resolution as the human eye — held at one foot away, the iPhone 4's pixels are too small to see. After reading an earlier Slashdot post about an expert disputing Jobs' claim, I decided to run the numbers myself. I found that Jobs is correct for people with normal vision, and the expert was using numbers for theoretically perfect vision. So to most people, the iPhone 4 display will look unpixellated."
Re:Wrong or right (Score:2, Informative)
Again though, why the use of meaningless words? Couldn't he have just said "the resolution/DPI is so dense that your eyes won't be able to distinguish individual pixels"? What, does the average Apple customer really seek the need of some special word to wrap up the device's capabilities in? And if they do, what does that say about their average customer?
I think it's insulting to the people that buy Apple's products, regardless of whether people seek it out or not.
Because you sell the sizzle, not the steak.
Re:As long as ... (Score:1, Informative)
I wonder if someone had an Evo, if they could just turn on Wifi hotspot and let Steve connect through that.
Wifi hotspots were actually the problem. There were over 500 access points in the room because of MiFis and phone-generated hotspots. I really doubt that one more would have helped.
math failure (Score:5, Informative)
it's alright, the math assumes that nobody is nearsighted. Since nearsightedness is very common, the article's comments don't hold true at all.
Some people can see magnitudes smaller arcmin than .6 up close, in fact like .2 or so. [wrongplanet.net] Anyone with 20/10 vision (which is common with correction such as eyeglasses or contacts) is going to still see plenty of pixelation.
It's still a substantial improvement in pixels, but the article is incorrect.
pixels and dots per inch are different (Score:4, Informative)
The human eye can resolve much finer than 300 dpi --- 400 dpi is where fonts start to look nice on a laserprinter (notably the NeXT laserprinter had a 400dpi mode in addition to the then more standard 300dpi --- it was distinctly noticeable when one changed printing modes) and imagesetters are easily differentiated by their output at 1,270 ppi vice 2,540 ppi (and there are models which go higher) --- see the book _Counterpunch: Making Type in the 16th Century, Designing Typefaces Now_ by Fred Smeijers for electron micrographs and a discussion of this which shows that the human eye can easily see the thickness of a 1/1,270th of an inch curl of steel.
Granted, the iPhone screen is 326 _pixels_ per inch, so one gets anti-aliasing, yielding a higher effective dpi, and possibly sub-pixel rendering, but screens need to get better yet.
Image resolution is measured in several ways:
ppi (pixels per inch) --- input / file resolution
dpi (dots per inch) --- output resolution for a single ink colour
lpi - (lines per inch) --- output resolution for ``halftones'' which allows the simulation of multiple levels when one can only do on/off --- newspapers use ~85 lpi, uncoated stock in books ~133lpi, magazines 150 lpi or higher, art books 200 lpi --- different printing processes/tecniques are used for better quality or fewer generations
A pixel is a ``picture element'' a unit of a raster grid which can be more finely differentiated than just black or white --- the coarsest pixel I can think of would be the monochrome NeXT Cube (and later Slabs) which had black, white and two shades of grey.
Try putting a 326 ppi greyscale image of a Gustav Doré engraving on the iPhone and compare that to the actual engraving in a book --- the difference between them will be obvious to anyone w/ good vision.
Different printing and halftoning techniques make lpi rather complex --- stochastic screening does away w/ it for example and exhibits improvement to the limits of output resolution --- 3600 dpi on some imagesetters.
Re:Print Resolution (Score:4, Informative)
Now, what I want is a 21' monitor with the same dpis, instead of crappy 1080p resolutions, no matter the monitor size.
Assuming you meant a 21inch monitor (at 16x9 aspect ratio), that would be about 18.3" wide and 10.3" tall. At the iPhone's 326 PPI (note that PPI is not per square inch), that would result in a display running at approximately 6,000 x 3375, or over 20 million pixels. At 60 Hz, assuming 3 bytes per pixel, that's about 29Gbit/s uncompressed. HDMI tops out at 10.2Gbit/s, DVI at 7.92Gbit/s (dual-link), so you'd need to come up with some other way to push all those pixels to the display or have the display accept multiple HDMI/DVI inputs (the resolution would be comparable to a 3x3 setup of normal-resolution monitors, which is more than something like eyeFinity can handle at this juncture).
If you're talking about a 21 feet wide diagonal screen, then you're looking at 72,000 x 40,500. I think that would be a little excessive.
Re:math failure (Score:2, Informative)
Re:Wrong or right (Score:5, Informative)
you don't like iTunes that's fine... but what rock have you been hiding under that you don't know Apple removed the DRM the second they were allowed to?
Re:So It's catching my droid then? (Score:4, Informative)
Thing is, 20-20 vision isn't that good. Have you ever actually taken a good look at the chart that determines what 20-20 vision is?
It's normally 3rd or 4th from the bottom of the chart. I am shortsighted, and with my glasses on I could still read the bottom line on my most recent eye test, a few months back.
Calling 20-20 vision "normal" in this discussion is misleading at best, dishonest at worst. Especially since the author quotes Wikipedia, which says, and I quote: The significance of the 20/20 standard can best be thought of as the lower limit of normal or as a screening cutoff. When used as a screening test subjects that reach this level need no further investigation, even though the average visual acuity of healthy eyes is 20/16 to 20/12.
So there you have it, 20/20 isn't "normal", it's the bottom end of what is generally considered to be "normal" and below which one considers corrective vision (my words there).
True "normal" vision is more like 20/16 or 20/12, which gives a resolution of more like 0.8 to 0.6 arcmin - closer to the figures in the original article than in this one, making the original article more truthful than this one, and validating (to me at least) the accusation that Jobs' claim is hyperbole.
300 dpi is a magic number in publishing (Score:3, Informative)
Most print artwork is done at 300 dpi. It's a magic number in publishing. iPhone 4 is the first screen device that can show print artwork. We've been looking forward to this for about 20 years. You have to be a fucking idiot to piss on it.