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You may have noticed that there has not been a lot of coverage of the new iPad 3 here over the preceding six months. While many members of the new era media were working themselves into a speculative frenzy over what the unannounced and unspecified product would be, I was content to wait for the facts. And I have to admit that at least from the display perspective, the new iPad 3 finally lives up to its predecessor’s hype.
If you want to learn more about its display, I recommend an excellent column by DisplaySearch analyst Richard Shim: “iPad 3: Clarifying Display Issues”. He points out that the LCD panel (sorry, it is not the widely-rumored OLED display) has an impressive 2,048 by 1,536 pixel resolution, which works out to 264 pixels per inch (ppi). Apple also chooses to call this a “Retina Display” even though the pixel density is much less than the 326 ppi found on the iPhone 4. I expect that the explanation is that you are going to hold the iPhone much closer to your eye than the iPad, so the pixels need to be smaller. Whatever.
The news for me is that the iPad finally can display full high-definition images without scaling. Granted, the panel still uses the same old 4:3 aspect ratio as your grandfather’s television set, but at least it now has enough pixels to show 1,920 by 1,080 without scaling (though with plenty space left over for letterboxing). If you make the image scale to fit the width of the panel, however, things could get ugly as you stretch each pixel by 1.06 and two-thirds. (No, I haven’t seen an iPad 3 in person yet, but I sure hope that Apple has included a provision for watching movies that does not involve such scaling.)
Richard also points out that these smaller pixels mean less room for light to be transmitted (smaller aperture ratio) which translates to the need for a brighter backlight which in turn impacts battery life. He expresses his suspicion that the device has a larger battery to respond to this extra power draw, along with the additional power required for the new processor.
There appears to be some interesting innovation in this new tablet, which may help accelerate the spread of video entertainment to devices other than the tradtional television set.
Posted by Alfred Poor, March 9, 2012 5:00 AM
> things could get ugly as you stretch each pixel by 1.06 and two-thirds.
I don't have time to respond to the entire article ATM, but two-thirds? ??? Where did that come from?
- Tim...
Tim, 2,048 divided by 1,920 equals 1.066666666666667. That is the same as "1.06 and two thirds" though it would have been more precise to say "two-thirds of one hundredth". The risk of artifacts when making such a small scaling change is pretty large.
Alfred Poor
HDTV Almanac...
Ah, thanks for the explanation, Alfred. I've never heard such a thing described that way. I'm pretty sure I would never have figured that one out on my own.
As for scaling the image up by 6.66...% just to be able to say you filled all the pixels, that seems a bit silly. Not just due to artifacts. If you use a resampling filter, they won't be that bad (even the poorest ones scale pretty well). Though if you use simple resizing, it will definitely get noticably crusty-looking. I just tried scaling some video stills up, using the poorest-quality and fastest (Hermite) filter. With 2M pixels, artifacts aren't even noticable on my 25" screen. On a 10" screen, you'd never be able to see them at all. But because the extra GPU overhead (and battery consumption) isn't justified, to fill that ~half inch (128 pixels = 2048-1920).
I'd suspect (hope) they'd simply run it 1:1. But if they didn't, the main downside would likely be battery life impact, not artifacts, unless their ...
Alfred,
> The news for me is that the iPad finally can display full high-definition images without scaling. Granted, the panel still uses the same old 4:3 aspect ratio as your grandfather’s television set, <
Urg. Are we still on that old kick? The screens on tablets should be 16x9, because some of our content is 16x9? And a 4x3 panel is some-how "old-fashioned"? If the purpose of tablets was exclusively for video display of HD aspect-ratios, there might be some merit to that. However, they are also used extensively for reading materials (and other purposes). And based on all the PDFs I have, a 4x3 AR fits them vastly better in Portrait mode than 16x9. I know that because I have other tablets with narrower ARs (1280x800, e.g.), and the result is that when reading such content, there are huge wasted bands on top and bottom, which reduces the size of the (already sm...
Tim, I don't mean to imply that tablet screens should be 16:9; I'm only saying that if you do watch HD content on it (and I expect many people would want to), you're going to have 436 blank lines or about a third of the screen. That's going to bother a lot of people. (Be honest with me; how many homes have you been to where the image has been stretched vertically to eliminate letterboxing or pillaring? More than one is too many, and I've seen WAY more than too many.) And I'm not trying to pick on Apple; they were the ones that promoted the iPad2 as the ultimate movie viewing experience.
As for Apple defying the laws of physics, you and I know that they can't, but that doesn't seem to stop them from implying that they can.
Alfred...
Alfred,
> I don't mean to imply that tablet screens should be 16:9; <
Thanks for the clarification. From your remark about "same old" and "like your grandfather" that was the implication I drew. From day one, Apple made a conscious decision that a 4x3 ratio was best for handling the entire range of activities such a portable device could be used for. Not simply be optimized for one specific use-case. There's not much point in harping on that, because it's obviously never going to change. And I think it was the right choice, though I realize not everyone will agree. (BTW, I don't own one, if that's the impression anyone is getting, though I do own many other tablets, from 5-12 inches. Perhaps the better screen will finally convince me to make the leap.)
OTOH, Apple now has the first and only device with so much resolution that it could function well as a two-page landscape display. (Though the upcomin...
Oh, and while I'm no Apple fanboy, I don't think they're getting the credit they deserve in the media for what they have accomplished in one area. Assuming you believe that a 2048x1526 display is an achievement in itself, and of some value, which I do. As you pointed out, to provide that resulted in a 70% greater power usage than previous models. That's a lot. And they managed to provide that extra 70% power capacity without changing the size, the weight, or the price! That's a pretty amazing feat in and of itself, in my book.
Yet many in the media are writing it off as "pretty much the same old thing, except for a higher-rez screen". That overlooks the magnitude of what they did manage to pull off (essentially a 17-hour iPad2), which was really quite impressive (though not necessarily immediately obvious to all).
- Tim...
About Alfred Poor
Alfred Poor is a well-known display industry expert, who writes the daily HDTV Almanac. He wrote for PC Magazine for more than 20 years, and now is focusing on the home entertainment and home networking markets.advertisement
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