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The term “retina display” is tossed around with increased frequency and decreased meaning. Is there really a strict definition anymore? Screen mega-expert Ray Soneira of DisplayMate points out that the biggest monitor in your house has been retina all along.
There is a widespread misunderstanding of exactly what constitutes an Apple “Retina Display” — or any display that has an equivalent visual sharpness. While the first Retina Display on the iPhone 4 has 326 Pixels Per Inch PPI, all Retina Displays don’t need 326 PPI because the eye’s resolution is not based on linear Pixels Per Inch, but rather on angular resolution, so visual acuity depends on the viewing distance. That is why you take a standard vision test at 20 feet and aren’t allowed to walk right up to the chart and read the smallest letters on the bottom line — visual acuity depends on the viewing distance.
Apple’s Retina Display definition is equivalent to standard 20/20 Vision — your eyes won’t be able to resolve the individual pixels on the display provided you don’t look at the screen from too close a viewing distance. If you have 20/20 Vision and view the iPhone 4 from 10.5 inches or more its display will appear “perfectly” sharp to your eyes — meaning the display appears at the visual acuity limit of your eyes. If the display were any sharper with a higher PPI or higher pixel resolution your eyes wouldn’t be able to see the difference. That is what “Retina Display” means… Let’s see what PPIs are needed for other displays in order to qualify as a Retina Display:
The new iPad 3 and MacBook Pro have much lower PPIs than the iPhone 4 but Apple correctly markets them as Retina Displays because they are typically held further away from the eyes and therefore still appear “perfectly” sharp at their proper viewing distance. Below we have calculated the viewing distances needed to qualify as a 20/20 Vision Retina Display (defined as 1 arc-minute visual acuity). For a discussion on the difference between the Acuity of the Retina and 20/20 Vision Acuity see this article.
- The iPhone 4 with 326 PPI is a Retina Display when viewed from 10.5 inches or more.
- The new iPad 3 with 264 PPI is a Retina Display when viewed from 13.0 inches or more.
- The MacBook Pro with 220 PPI is a Retina Display when viewed from 15.6 inches or more.
On the other hand, the average viewing distance for living room HDTVs in America is around 7 to 10 feet, depending on the screen size. So to appear “perfectly” sharp with 20/20 Vision like the iPhone 4 Retina Display, HDTVs only need a proportionally much lower PPI in order to achieve “Retina Display” status and have the HDTV appear “perfectly” sharp and at the visual acuity limit of your eyes.
- Existing 40 inch 1920×1080 HDTV is a “Retina Display” when viewed from 5.2 feet or more.
- Existing 50 inch 1920×1080 HDTV is a “Retina Display” when viewed from 6.5 feet or more.
- Existing 60 inch 1920×1080 HDTV is a “Retina Display” when viewed from 7.8 feet or more.
Since the typical HDTV viewing distances are larger than the minimum distances listed above, the HDTVs appear “perfectly” sharp and at the visual acuity limit of your eyes. At the viewing distances listed above the pixels on a 1920×1080 HDTV will not be visible by a person with 20/20 Vision in exactly the same way as the Retina Displays on the iPhone 4, new iPad 3, and MacBook Pro at their viewing distances. So existing 1920×1080 HDTVs are “Retina Displays” in exactly the same way as the existing Apple Retina Display products. If the HDTVs had a higher PPI or a higher pixel resolution your eyes wouldn’t be able to see the difference at their proper viewing distances. So existing 1920×1080 HDTVs are already equivalent to what Apple calls a “Retina Display.” When Apple launches its own Apple Television it will almost certainly have a resolution of 1920×1080 and it will be a True Retina Display [for humans with 20/20 Vision at standard HDTV viewing distances].
Some manufacturers are introducing HDTVs with resolutions that are at least double the existing standard 1920×1080 resolution — 3840×2160 or more. They are often called 4K displays. Some reviewers have already claimed dramatically improved picture quality and sharpness — but that is impossible unless they have significantly better than 20/20 Vision or are watching from an absurdly close viewing distance. However, the higher resolutions are important for Digital Cinematography and cinema projectors that have large 10 foot or more screens. But note that there isn’t any consumer content available yet for resolutions higher than 1920×1080, so save your money and wait for the Apple Television with a true 1920×1080 Retina Display…
What are these inch and feet things you are talking about?
They’re part of a magical non-decimalised measuring system that pretty much everyone in the UK/ computing industry can visualised based on the fact that height, and screen dimensions, are measured in them, making it much more accurate to picture in your head.
So my TV has a retina display when viewed from a distance of 1/3 the length of a double decker bus? Or 1/17th the length of Nelson’s Column?
No, 9.6 Royal Egyptian cubits.
It be Witchcraft that they be talking. Call the Witch finder general immediately.
Does that mean my atari 2600 hooked up to a 30″ CRT has a retina display when viewed at a distance of 200ft?
“But note that there isn’t any consumer content available yet for resolutions higher than 1920×1080, so save your money and wait for the Apple Television with a true 1920×1080 Retina Display…”
Or buy a far less overpriced tv today?
They mean if you want the brand ‘Retina’ which Apple own. I don’t think it was meant seriously i.e. ‘if you really must have Retina, get this. But don’t.’
Who ‘owns’ the retina trademark. I’m guessing it’s Apple right?
Hmm, I’m not sure Apple can put a trademark on a part of your eye…
*Part of your i.
I looked at the new Mac Book retina display and i wouldn’t have noticed a difference if i wasn’t told.
As I’ve been saying for ages, Retina Display is pure Apple marketing hyperbole rubbish. It doesn’t mean anything, it basically means what ever Apple is trying to sell you right now, tomorrow it will mean something different.
Can we please learnt to ignore blatant marketing buzz words and concentrate on meaningful stats. We are suppose to be IT professionals rather than school children.
I am supposed to be an IT professional?!
*Tears up mechanical engineering degree*
What a load of rubbish. The OP can stay stuck in the long dead past of 1080p. Someone has forgotten how to think Tech.
The true that Apple’s Retina display is more of their special propaganda.
But there is NO comparing 1080p to 2160p. The TV and lap/pc world have (mostly) merged, but TV industry forced us into thinking that 1080 was good, not.
It is all about pix/line. More is and ALWAYS has been better. The fluidity and depth gained by a double resolution Tv/Monitor is highly anticipated in my household of 4HD tvs, 4 laptops, 2 tablets and 4 PC’s.
We have had affordable access 1024 lines since the early 90′s! Woopdedo we settled on 1080… gross. Worse yet is how crap 720p is, how can this even be considered hi-def? double gross.
If we had followed proper tech curves we should have been in 4k for a few years now. Industry settled for 1080, and we bought it.
Remember lots of sci-fiction is now days for sale.
Cellphones!
Full wall TVs!
Time to wake up and walk into the next decade. 1080p sucks.