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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bplewis24 - Monday, July 12, 2010 - link
Consumer Reports confirms what I have commented on earlier about this article: that the "best case scenario" testing of one phone is clearly an attempt to excuse away this clear design flaw in a biased review. See the article here: http://blogs.consumerreports.org/electronics/2010/... .And watch the video. This testing was done in a controlled environment with an RF Isolation Chamber that is impervious to outside radio signals. I suggest you guys stop misleading the tech nerd population with this review now, and revise it.
Brandon
plastic_avatar - Monday, July 12, 2010 - link
How can you not respect the research of someone who slides in an apt geek reference?zholy - Tuesday, July 13, 2010 - link
Only Apple can release a product with such a design flaw and respond to complaints with either "you're holding it wrong" or "buy another product to make it work correctly". Any other company would have their product returned in droves, Mac fanatics just say "ok"Hengie2000 - Saturday, July 17, 2010 - link
Help! I am a wireless tech that uses field test daily to survey in building wireless projects, but the iphone 4 or 4.0 upgrade lost that capability. I am willing to pay for someone to make a field test app or follow the steps that Brian and Anand have listed in this story. Is there any way to reach these guys for more details to get field test running on the iphone4? Does this give full field test menus or only replaces the signal bars with decibels?Stang289 - Monday, July 26, 2010 - link
It would be great if you had Palm Pre Plus and Pixi Plus performance numbers included in smartphone reviews. I would like to see how they stack up against other smartphones.marxster - Thursday, September 9, 2010 - link
...after all that, I'll give you my real world experience. We have a 3Gs and a 4 in our household. The 3Gs always shows more bars and does not drop calls at all while my iPhone 4 does drop calls and has less bars.We live far away from the closest tower and the iphone 4 doesn't ever get better reception here than -103db.
I'm now afraid to receive calls because I know they'll be dropped. Makes my phone useless.
I should say that both phones are on the latest iOS version and there isn't much of a difference whether I use a case or not.
By the way, please explain this to me. Why did Apple bother to spend millions of dollars shipping out cases when they clearly don't get rid of the problem. When I cup my phone with the case on, the bars drop just the same as without.
MisterQED - Wednesday, October 20, 2010 - link
I am not a member of the “tin foil hat” crowd, I’m a guy with a physics degree and a Ham license, so I know a bit about radios. What I am about to point out seems so obvious to me, but I have never heard it discussed anywhere. Your article discusses the effects of having a exposed antenna as it effects phone reception, but that misses the main point, this is a receiving and transmitting antenna. Having skin contact with a transmitting antenna is not safe. Allow me to explain my thought process and tell me if I have a flaw in my logic.1) Constant irritation causes cancer. Whether it is fiberglass fibers, silica dust or coal dust in our lungs, to UV radiation from skin exposed to the sun, if you irritate an area consistently for long periods of time, you are just asking for cancer.
2) RF radiation from most phones is a subject of worry and present discussion, but it doesn’t worry me. RF radiation is a worry because it will cause electrical conduction thru body tissue. This would be an irritation and consistent irritation can lead to cancer. RF radiation from most phones has two methods of conduction, capacitive and inductive.
a) Capacitive needs: a sizable area, small dielectric distances and high frequencies. Cell phones have the high frequencies, but all other designs keep minimal gaps between antennas and the operator’s skin. Also the operator’s finger tips provide a rather small area to support capacitive conductance.
b) Inductive conduction needs frequency matched radiators to allow conduction i.e. a good antenna on each end. Body parts make poor antennas, and bodily dimensions generally don’t match the proportions of ideal radiators, so inductive conduction isn’t really a worry.
3) iPhone 4s, unlike any previous device, allow a third and a magnitude more effective connection between an operator and a transmitting antenna, a resistive connection. All a resistive connection needs is a low resistance, which skin has when sweaty or damp and the antenna has if it is not covered by a non-conductive coating. To add insult to injury, this contact de-tunes the antenna making it less efficient. This inefficiency causes the transmitter to up the power output as cell phones work on a “yell loud enough to be heard” system, so the worse the reception the more power the phone will pump into the antenna to be able to communicate with the cell tower.
So unless you can show me where my logic has lead me astray, I would expect that in the future some percentage of the population that use an iPhone without a case may find a small possibly cancerous mole forming on one of their fingertips.
That is a bigger problem than some dropped calls, so why didn’t you mention it.
smithpercy - Sunday, November 14, 2010 - link
Does this mean that I could cold weld a suitable socket to the gsm antenna side strip to allow a patch cable to an external antenna and get reception in the very marginal areas that I spend most of my time in?? I know that the shield would have to be grounded but that could be done thru one of the other connectors. I understand that would void the warranty, and give apple a conniption fit but that is their problem.keri - Thursday, February 24, 2011 - link
serious question here.jessicacoles - Saturday, December 12, 2020 - link
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