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Apple's iPhone 4: Thoroughly Reviewed

 by Brian Klug & Anand Lal Shimpi on June 30, 2010 4:06 AM EST
270 Comments | Add A Comment
270 Comments

More Display

It's obvious how Apple settled on 960x640; it's four times the resolution of the previous iPhones. However, instead of decreasing text size, iOS 4 scales appropriately, and the size of everything remains the same. The result is that there are small details everywhere that pop out. Apple's icons on the home screen are the first that really pop out, and new iOS 4 optimized applications will bring that increased detail as developers add higher resolution artwork.

The display panel itself uses a subset of IPS (In Plane Switching) display technology called Fringe Field Switching (FFS). Where IPS switches the crystal polarization in the plane of the display with two opposing electrical substrates composed of semi opaque metals (which decreases transmission and viewing angles), FFS uses considerably less metal by arranging the electrodes in a comb like structure.


See that - it almost looks like a comb. Or an impulse train. Or Dirac comb. So many combs.

The result is that there's considerably less metal in back and in front of the pixel, resulting in much higher transmission of light through the display, and higher brightness for a given backlight level. Using FFS to drive pixel switching is critical here because of the high dot pitch in the iPhone 4's display.

The other interesting difference between iPhone 4's retina display and previous displays is that the digitizer is in optical contact with the display itself. There's no longer an air gap, and as a result, no longer any opportunity for dust to gradually work its way inbetween. Over time, I've noticed a few dust specks creep in on my 3GS, it does happen. The digitizer and display panel are essentially laminated together. The added benefit is that fewer material interfaces results in fewer internal reflections - think the "super" in Super AMOLED but applied to TFT. That's what Apple has done here.

Apple is using Corning's Gorilla glass which touts hugely increased scratch resistance and robustness. Both the front and back of the iPhone 4 are that same type of glass. I've noticed a few superficial scratches (called sleeks) that have appeared on the back, but really the true test will be how the phone looks after 6 months in the pocket. It's interesting that the iPhone capacity markings have disappeared from the back of the phone - no doubt this was done so Apple could make one part and one part only for each color.

The rest of the details are in the specifications. Apple advertises increased brightness of 500 nits and a contrast ratio of 800:1. We measured, and our iPhone 4 exceeded specs at 571 nits and just under 1000:1 contrast ratio.

Note that the HTC EVO 4G is missing as Anand has it, but it's on its way to me. As soon as I get it, I'll measure display brightness, black point, and contrast and update these results. In addition, the HTC Droid Incredible (and thus Nexus One) contrast is effectively infinity by the way we calculate, due to pixels being completely turned off in the black state. In addition, I'm led to believe that the AMOLED's PenTile grid throws off our numbers when measuring brightness. I've run and rerun this test, it keeps coming up that way. 

Next to the iPhone 4, the 3GS display really shows its age. It leaks light when displaying black, with an absurdly high black point of nearly 3 nits. Just looking at the lock screen on the iPhone 4 next to the 3GS it's readily apparent how much better blacks are. iPhone 4 easily bests the 3GS but still isn't quite as contrasty as the Incredible or Nexus One AMOLED displays, or the IPS in the Motorola Droid. You do get higher resolution and brightness, however, but nothing is free.

Going from the iPhone 4's display back to the 3GS is pretty painful, but going back to even relatively high dot pitch displays on the desktop is painful as well. Even on the "high resolution" MacBook Pro with 1680x1050 display, displaying an iPhone 4 screenshot at native resolution uses up 91% of the height. If there's one thing I hope the iPhone 4 display does, it's generate demand for 300 PPI level desktop displays - the era of 110 PPI displays being the norm needs to end now.

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  • Lemurion - Friday, July 2, 2010 - link

    I was disappointed that you they only compared the iPhone 4 screen to the 800 by 480 AMOLED screens on some of the Android devices. As far as I know, all those devices use the Pentile system, which reduces the crispness of text.

    I would have really liked to compare the new Apple screen to the Motorola Droid's 266 PPI screen and see how noticeable the difference there was.

  • Matt Campbell - Friday, July 2, 2010 - link

    Nice investigation work on the signal strength. Just wanted to point out that AnandTech is cited in the Apple iPhone 4 software fix story on CNN today. http://www.cnn.com/2010/TECH/mobile/07/02/apple.ip...

  • Bad Bimr - Friday, July 2, 2010 - link

    http://www.cnn DOT com/2010/TECH/mobile/07/02/apple.iphone.apology/index.html


    Apple admits iPhone 4 reception issues, says fix is coming

    After initially dismissing the reports about the iPhone 4 antenna reception issue, Apple has officially admitted it exists, promising a software fix in a couple of weeks. There's a catch, though.

    Apple's promised fix may not be good news for users experiencing the problem. Apple claims it has erroneously calculated the formula which displays signal bars on the iPhone, and therefore the iPhone has been showing too many bars in areas with weak signal strength.

    Here's how Apple explains it:

    "Users observing a drop of several bars when they grip their iPhone in a certain way are most likely in an area with very weak signal strength, but they don't know it because we are erroneously displaying 4 or 5 bars. Their big drop in bars is because their high bars were never real in the first place."

    Unfortunately, this seems like Apple is only acknowledging one part of the problem. Anandtech's in-depth analysis showed that the signal drop when you grip the iPhone 4 by its lower-right side is very real.

    Therefore, Apple's fix probably won't fix that part -- arguably the biggest part -- of the problem, and will merely make the iPhone 4 display fewer bars in weak signal areas.

    Interestingly enough, Apple claims the miscalculation was present "since the original iPhone," so the fix will apply to older generation iPhones as well.

    Here's Apple's official announcement:

    Dear iPhone 4 Users,

    The iPhone 4 has been the most successful product launch in Apple's history. It has been judged by reviewers around the world to be the best smartphone ever, and users have told us that they love it. So we were surprised when we read reports of reception problems, and we immediately began investigating them. Here is what we have learned.

    To start with, gripping almost any mobile phone in certain ways will reduce its reception by one or more bars. This is true of iPhone 4, iPhone 3GS, as well as many Droid, Nokia and RIM phones. But some users have reported that iPhone 4 can drop four or five bars when tightly held in a way which covers the black strip in the lower left corner of the metal band. This is a far bigger drop than normal, and as a result some have accused the iPhone 4 of having a faulty antenna design.

    At the same time, we continue to read articles and receive hundreds of emails from users saying that iPhone 4 reception is better than the iPhone 3GS. They are delighted. This matches our own experience and testing. What can explain all of this?

    We have discovered the cause of this dramatic drop in bars, and it is both simple and surprising.

    Upon investigation, we were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong. Our formula, in many instances, mistakenly displays two more bars than it should for a given signal strength. For example, we sometimes display four bars when we should be displaying as few as two bars. Users observing a drop of several bars when they grip their iPhone in a certain way are most likely in an area with very weak signal strength, but they don't know it because we are erroneously displaying four or five bars. Their big drop in bars is because their high bars were never real in the first place.

    To fix this, we are adopting AT&T's recently recommended formula for calculating how many bars to display for a given signal strength. The real signal strength remains the same, but the iPhone's bars will report it far more accurately, providing users a much better indication of the reception they will get in a given area. We are also making bars one, two and three a bit taller so they will be easier to see.

    We will issue a free software update within a few weeks that incorporates the corrected formula. Since this mistake has been present since the original iPhone, this software update will also be available for the iPhone 3GS and iPhone 3G.

    We have gone back to our labs and retested everything, and the results are the same- the iPhone 4's wireless performance is the best we have ever shipped. For the vast majority of users who have not been troubled by this issue, this software update will only make your bars more accurate. For those who have had concerns, we apologize for any anxiety we may have caused.

    As a reminder, if you are not fully satisfied, you can return your undamaged iPhone to any Apple Retail Store or the online Apple Store within 30 days of purchase for a full refund.

    We hope you love the iPhone 4 as much as we do.

    Thank you for your patience and support.

    Apple


    Just like apple, finally admitting a problem, pleasing the fan boys by saying it will be addressed and doing nothing to fix it. I am so glad I never jumped on the apple bandwagon.

  • fischerm83 - Friday, July 2, 2010 - link

    So i was reading various news articles today and saw that apple finally figured out/admitted to what you guys found out earlier this week...

    *quote*
    Now the company says its engineers have made a "stunning" discovery. Reception is poor and calls may be dropped because not only are people holding the phone wrong, but they also think they have a better signal than they do. In the statement, Apple says that it has made a mistake in the formula that calculates the number of bars that display the signal strength on all of its iPhones.

    "We were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong," it said in a statement.
    *quote*

    Full Article:
    http://news.cnet.com/8301-30686_3-20009564-266.htm...

    Nice work guys, keep up the amazing work!

  • anandreader - Friday, July 2, 2010 - link

    Brian-
    I'm confused as to what had to happen to get Fieldtest onto the iphone 4. Understood the bit about jailbreaking the iphone3 but didn't understand how that information got transfered to the 4.

    Could you elaborate a bit there?

  • Per Grenerfors - Friday, July 2, 2010 - link

    Thanks for the great review, AnandTech.

    In countries where 3G coverages isn't spotty like a teenagers face, the whole antenna/at&t/verizon debate is just utterly unnecessary.

    Apple is the only brand name in tech today that's recognized by the broader public. Their products therefore make a big splash in the media when they hit the market. But the bigger splash you make, the more mud comes floating up from the bottom. Like people complaining with a spec sheet in hand without ever having seen the device in real life. Or just plain old haters. This is the downside to fame. But I'm sure Apple's laughing all the way to the bank.

  • Stokestack - Friday, July 2, 2010 - link

    A case isn't an acceptable workaround for this. I don't buy a thin phone to bulk it up and junk it up with a cheesy case or add-on of any kind.

    While I'm not planning on getting an iPhone 4, if I had one and wanted to keep it I'd try to spray a coating onto the antenna band. I'd mask the front & back, the buttons, and any seams, then spray with polyurethane or something. While it would be microscopically thin, there's be no direct contact with skin. And really, that's what you said you expected Apple to have done anyway. Let's see if it would work.

    Excellent review. The hack to get the numeric signal strength rocks.

  • Fulle - Friday, July 2, 2010 - link

    Thank you for the review. It was useful to be able to look at something that was detailed, and included facts, good and bad, without a ridiculous amount of bias. It's obvious that Anand likes, or at least really wants to like most Apple products, but it was nice that that didn't get in the way of the review.

    The new iPhone seems to be an OK device that's on par with new Android smartphones in way of hardware... The screen's got 20% higher pixel density than the Droid, but 50% worse contrast ratio, and worse black quality... Java performance is clearly inferior to a Nexus One, but browsing performance is competitive (I'd say good, but I think all handsets have shit browser performance). Its sleak and thin, but it has no hardware qwerty. The 5MP camera produces low noise, but, the white balance is messed up, making it overall inferior to the camera in a Nexus One or HTC Incredible (or Moto Droid, even, IMHO... screwed up over-saturated colors with bad white balance are a big deal to me). Overall, it's an average device when put up against worthy competition (EVO4G, DroidX, HTC Incredible, Nexus One, or even a Moto Droid).

    But, that's before you have to deal with the obvious design flaws. Glass panels on both sides? WTF? Uninsulated external antenna? These aren't minor flaws here.

    So, overall I'd say that the new iPhone is inferior to at least 6 Android smartphones.... and at first I grin at that... but then I'm disappointed and mad. Apple has helped make the smartphone market the competitive environment it is today, and when they drop the ball like this, it means that other venders don't have to raise the quality of their devices to compete. It's just fortunate that Android has so many hardware OEMs, like HTC, Samsung, and Motorolla, all competing with each other... or else I'd be afraid the only thing the iPhone4 would push in competition is a higher ppi on the screens.

    Lets hope this helps push the Cortex-A9 equipped Android's this winter to include higher resolution in their displays... but, man, I'm disappointed with this device.

  • tgibbs - Friday, July 2, 2010 - link

    Does zero dB represent a standard absolute signal strength or is it an arbitrary reference value that will differ for different phones?

  • navderek - Saturday, July 3, 2010 - link

    The signal is actually measured in dBm which means it is a reference to 1mW of power.
    For example -30dBm = 1000 times less that 1mW = 1uW
    1 microwatt does not seem like much, but actually this is a very strong signal for the mobile and you would rarely have that much power arriving at your handset from the tower. In good conditions, close to the tower or serving antenna with minimal obstructions you could expect about -50 to -60 dBm (-60dBm = 1nW (nanowatt). The system is designed to deal with such small signals...this is why I laugh when people are worried about cell tower "radiation" when actually 5 min. in the sun is a bazzillion times more radiation than what's coming out of a tower....cellular towers that is, broadcast radio towers or paging systems are another story!

    But I digress...to answer your question simply, zero dBm simple equals 1mW.
    Zero dBm signifies that there is no difference in ratio from the reference of 1mW.
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