Apple's iPhone 4: Thoroughly Reviewed
by Brian Klug & Anand Lal Shimpi on June 30, 2010 4:06 AM EST- Posted in
- Smartphones
- Apple
- iPhone 4
- Gadgets
- Mobile
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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Brian Klug - Wednesday, June 30, 2010 - link
You know, I realized that seconds after writing it and decided that it'd just be too much to go into a detailed explanation. I corrected it to something much simpler ;)-Brian
zerosomething - Wednesday, June 30, 2010 - link
Fantastic article thanks for the in-depth review.From the article on page 5. "...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."
There is actually a Model number on the back of mine. So there will need to be 4 different backs. However they can make one part for each color for the fronts. In reality they will have to make 2 fronts and 4 backs to cover all capacities and colors which is one more than they had to make for the 3G/GS phones.
Wow I'm picking such tiny nits in a fantastic article. Guess everything else was so through this one stood out.
Shadowmaster625 - Wednesday, June 30, 2010 - link
If you already own an iPhone, how is it worth it to upgrade? You said so yourself... tiny text is still tiny. So what are you getting for hundreds of dollars that the 3GS doesnt give?Guspaz - Wednesday, June 30, 2010 - link
I'm a 3GS owner in Canada (Fido is my provider), so we've had tethering ever since iOS 3.0 launched roughly a year ago. I noticed two small errors in the discussion on tethering, and felt one thing was possibly mischaracterized.First, I'd like to give a brief mention of how tethering works with Fido (and other Canadian providers). We've always had data caps on our iPhone data plans. Typically, you get something vaguely like 1GB for $30, but both the 3G and 3GS launches featured limited-time 6GB for $30 offers that are permanently grandfathered.
Fido/Rogers policy is that all users with a 1GB dataplan or higher get free tethering (this appears to be a permanent position), which uses the same data cap. So, in effect, the vast majority of Canadian iPhone owners have tethering.
The first error is "With the iOS 4 upgrades the iPhone 4 supports tethering over Bluetooth or USB." Tethering is not new in iOS 4; it's been supported since iOS 3, and tethering support is identical in iOS 4.
The second error is "You also need to either have Bluetooth enabled or be connected via USB to the computer you wish to tether." Firstly, Bluetooth doesn't need to be enabled before enabling tethering. If you enable tethering while bluetooth is disabled, a prompt appears asking you if you want to enable bluetooth, or just tether over USB. Secondly, not really an error but an important clarification: on Windows, you can only tether via USB with a computer that has the iPhone tethering drivers installed.
These tethering drivers are bundled with iTunes, and cannot normally be installed separately, but iTunes and the drivers have separate uninstallers in Add/Remove Programs. This means that you can set up, say, a friend's laptop to tether via USB by installing iTunes and then uninstalling iTunes, leaving the drivers behind. Annoying, but workable if bluetooth is unavailable.
In terms of the mischaracterization, the performance of tethering is called into question. This may be an AT&T networking issue, as I've not experienced the performance issues. Generally, whatever the networking performance my phone is achieving, a tethered computer will also achieve. There is no difference between the two, so any connectivity issues are strictly network-related rather than tethering-related. Performance is generally good; latency is usually 130-150 to a close remote host, and downstream bandwidth is 1-5 Mbps depending on congestion/location. Upstream, since the iPhone 3GS lacks HSUPA, is limited (335Kbps in practical tests), but tends not to vary quite as much as downstream based on signal quality.
Upstream performance isn't stellar, but it is relatively reliable, if a tad slow. Packetloss is rare if the phone has a good signal. I regularly use tethering to get laptops connected on the road, and remote desktop over a tethered connection is very snappy, and is amazingly faster than on-device RDP.
Mike1111 - Wednesday, June 30, 2010 - link
@Anand:"Even if you just cover the camera it’s actually better to make calls over FaceTime than 3G based on the sound quality alone."
Cover the camera? Why? Just press Home and you have a traditional voice-only VoIP call with reduced bandwidth.
Also I would like to see some comparison to the competition. Video calling on phones exists for quite some time. How about a comparison of video and voice quality?
And in regard to the bandwidth requirements, would it have been realistic to allow FaceTime over 3G?
You also mention that the compression is too high for text, is that because of a bad compression algorithm or codec, too low resolution or bandwidth? Is that something that realistically could have been done better?
strikeback03 - Thursday, July 1, 2010 - link
Does returning to the home screen actually kill the camera? That would be annoying if you only wanted to look at your calendar or something else on the phone while in a video call.Mike1111 - Thursday, July 1, 2010 - link
As with a normal (cellular) call you can always resume the video by tapping on the green status bar (call active...).Oyeve - Wednesday, June 30, 2010 - link
How is the sound quality? Is there an EQ (missing from all things "i")bkman - Wednesday, June 30, 2010 - link
An interesting review but flawed by bad metrics. The authors confuse absolute power measurement, dBm, with relative power measurement, dB. For example, a signal strength drop from -51dBm to -83dBm is not a drop of 24dBm, it is a drop of 24dB.hgoor - Wednesday, June 30, 2010 - link
Hi, I loved the review: really (and mean really) thorough! Thanks for that.However: unless I blacked out while reading and missed it: what about the noise canceling microphone? How does that work? I guess it's not that noticeable as you only mention it one time?
I'm very curious to find out if it's a feature that helps? Also: I wonder if it can be used for listening to music? I have an expensive pair of headphones from Sennheiser, but I wonder if it can be used (in the future?) to help listen to music (and on/or on the phone) when you have a lot of ambient noise?
Would be nice if you could clear that up. Also: I wonder how the iPhone 4 holds up against the new Samsung 1ghz powerhouse?
Keep up the good work!