A Professional Perspective On Apple's Retina Display

Reader BWJones, who is a retinal scientist, sends in this detailed analysis of the iPhone 4's "retinal display," which includes photomicrographs of the display pixels of earlier generations of iPhone as well as the iPad. Well worth a read. "... as you can see from these images of the displays I captured under a microscope, the pixels are not square. Rather they are rectangular, and while the short axis is 78 microns, the long axis on the iPhone 4 pixel is somewhere in the neighborhood of 102 microns. ... While [an earlier analysis by] Dr. Soneira was partially correct with respect to the retina, Apple's Retina Display adequately represents the resolution at which images fall upon our retina. ... [I] find Apple's claims stand up to what the human eye can perceive."

Comments

Re:We knew this years ago ...

[Anonymous Coward]

.. which is why "laser quality" is 300 dpi. We knew fax looks like shit because it's 200 dpi. It's why chemical photo prints are almost 300 dpi. Why print artwork is done at 300 dpi. The "300 dpi pleases the retina" thing is like 25 or more years old. 300 is the most important point on the resolution scale.

As someone that used to work for an agency:

300 DPI represents an reasonable economics tradeoff between accuracy and cost. You can have 1270 DPI (professional photo typesetters run that high), but how much do you want to pay for it? Those machines are $500k+. And yes, your eye can tell the difference between 300 DPI and 1270 DPI.

Artwork developed by print agencies is done at 300 DPI and no higher because of limitations on file transfer size and professional printer RIP speed. Trust me, if an 8" x 10" photo could be squashed into 3-5MB and rasterized in a short amount of time at 1270 DPI, there would be printing equipment and printers offering that as a service overnight.

Finally, standard 35mm film is around 10,000 DPI, dude.

Re:B-b-b-but I thought Apple was a marketing compa

[Bigjeff5]

It's impressive, but it isn't super impressive. The Toshiba Portege G900 already had a screen at 313ppi, and Sony Erickson X1 is 312ppi.

What makes it newsworthy, is Jobs said (I paraphrase) "It's as good as the human eye can perceive." That's why he named it the "retina display".

A scientist with a Ph.D. came along and called bullshit, saying that the human retina can perceive pixels much higher.

The Ph.D. in this article respectfully disagreed, and said the previous scientist:

A.) Used the wrong figure for retinal resolution when he made his calculations (0.5 arcminutes instead of the 0.78 arcminutes established by a recent, authoritative study) and

B.) Failed to factor in losses in the optics of the human eye regarding how much light will actually hit the retina.

With A fixed and B factored in, the scientist concludes that the practical limit of the human retina (what it can distinguished given the amount of light that hits it) is 286ppi when held at 1 foot away from the eye (the ideal distance for viewing detail). The iPhone is well above this, at 326ppi, which means Jobs was right, and the name is apt.

It's worth noting that there are quite a few phones that beat the 286ppi limitation, but the iPhone has the highest.

Basically it looks like we don't need any higher resolution than what the iPhone and others have achieved, anything more would be pointless.

That, to me, is very impressive.