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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JAS - Wednesday, June 30, 2010 - link
The build quality of the iPhone 4 is outstanding. It reminds me of Nagra (Swiss-made) professional tape recorders I have used. Very solid.The edges of the iPhone 4 are not as smooth as those on the iPhone 3GS; but they aren't "sharp" or prone to cutting your pants when you slide the device into your pocket.
Still, I would want to use a rubber/silicone "skin" on the iPhone 4, not just a bumper, primarily to improve its grasp.
jsbruner - Wednesday, June 30, 2010 - link
I see the reception bar issue as well but do not experience any dropped calls because of it. However the biggest issue I have is with the proximity sensor. I have accidentally hung up numerous times because the screen lock turns off and the buttons become active. I watched myself in a mirror talking and I see the phone flickering on and off. Have you seen this issue at all? Would the bumper minimize this issue?Great article.
Wolfpup - Wednesday, June 30, 2010 - link
While in theory I'd love higher resolution displays on monitors, in practice they're already too high, and can't get any higher until somehow operating systems are able to offer true resolution independence where ANY program (even if it's written in 1988) will be flawless scaled so it's the right size at a given resolution. So far the ONLY example in the computer world of this being done right is on Palm devices, where they just quadrupled the resolution and on older programs 1 pixel = 4 real pixels. Presumably it's the same on iOS.But until OSes can do that that successfully on ANY content on ANY monitor at ANY resolution, raising the resolution is a TERRIBLE idea, as we're already WAY past the point of usability on a lot of displays, since stuff just keeps shrinking rather than adding detail.
inperfectdarkness - Wednesday, June 30, 2010 - link
"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."i could not have said it better. 1080p on a 17" screen is pathetic for a laptop.
minememy21 - Wednesday, June 30, 2010 - link
I registered just for the sole purpose of saying thank you to Brian and Anand.I really appreciate the amount of work and objectivity you've put in this review. I don't know of any other site with the same level of dedication and thoroughness.
Please don't pay attention to the few, vocal, and overly sensitive anti-apple crowd and just continue writing the way you do.
HilbertSpace - Wednesday, June 30, 2010 - link
"Perhaps even use diamond vapor deposition (like they did with the glass screen atop the iPhone 3GS) to insulate the stainless steel from users." -The Real Story on iPhone 4's Antenna.There's no way apple used physical vapor deposition (PVD) on the iPhone 3GS, way too expensive! Supposedly a Nokia Vertu phone adds a TiC coating - the cost - oh only ~$15000!
gronkman - Wednesday, June 30, 2010 - link
The word on the grapevine is that the antenna issue will be dealt with by an upcoming software update. What I am interested in is whether it will really change the antenna attenuation, or whether it will "fix" the bars just by not showing the bar degradation. I'm hoping AT will do an in-depth look at the update when/if it comes out.thomas.magnum - Wednesday, June 30, 2010 - link
I am not sure what you mean when using 40% in the context of the bar. But I think you need to improve the discussion of dB. Because it runs on a log scale, changes in dB are more complex than just looking at dB1-dB2 and computing percentage. You really need to think about 10^(dB/10). I would bet that the bars are setup to be representative of a dB scale. NOT simple percentages base on dB numbers, like you're trying to do.The0ne - Wednesday, June 30, 2010 - link
Your comment reminds me of richter scale :) Most people will look at 6.0 and 7.0 and say oh that's nothing hahaha If only they knew they'll be completely shocked. Sorry, I had a good laugh out of this.strikeback03 - Thursday, July 1, 2010 - link
Of course that is also assuming they think the Richter scale is still in use.