The hardware design hasn't changed from the one we already knew about. It uses the same materials as the prototype: Black glass and stainless steel rim. It fits with the rest of the Apple product line, from the hard edges to the Dieter-Ramsesque utilitarianism of the iMac and the iPad.
The black glass is aluminosilicate glass. Apple claims this glass is "chemically strengthened to be 20 times stiffer and 30 times harder than plastic." According to them, this makes it more scratch resistant and durable than the previous generation.
The size is smaller than the previous generation: 34% thinner than the iPhone 3GS. Although it is 3 grams heavier. According to Apple, it's the thinnest smartphone ever. It has split buttons for volume, unlike the current iPhone 3GS, all made in stainless steel.
The stainless steel rim
The stainless steel rim gives the structure to the iPhone, and acts as part of the antenna for 3G and Wi-Fi. In theory, this will greatly increase the reception abilities of the new iPhone 4.
The iPhone 4 is 4.5 x 2.31 inches, and 0.37 inches thick. It weighs 4.8 ounces (137 grams).
The new big brain
It has an Apple A4 chip inside, just like the iPad. Inside the A4 there are a few interconnected chips: A Cortex-A8 main processor unit—the main brain—paired with a PowerVR SGX 535, which handles the high definition graphics of the new iPhone. These are directly connected with each other and two low-power 128MB DDR SDRAM chips. Since all these components are in the same chip, Apple claims the iPhone 4 can process data more quickly while consuming less battery than before.
The A4 also consumes less power because its sub-components can be switched on and off when they are not needed, shaving watts whenever it's possible.
The battery is 16% bigger than the current one. Coupled with the A4 processor and new display, it results in a longer battery life: Apple claims 40% more talk time. Here are their figures:
• Talk over 3G: 7 hours.
• Browsing over 3G: 6 hours.
• Browsing over Wi-Fi: 10 hours.
• Video: 10 hours.
• Music: 40 hours.
• Stand-by: 300 hours.
The 3.5-inch multitouch screen has a resolution of 960 × 640 pixels. Apple calls is the Retina Display, and it has four times as many pixels as the current iPhone 3GS' display. The screen has 326 pixel per inch resolution, a higher definition than your typical magazine, a quality that shows in the screenshot.
Apple claims that this IPS-based display—the same technology as used in the iPad—also has 800-to-1 contrast ratio which is four times better than the 3GS, with a higher viewing angle.
The apps will take automatic advantage of the increased relative resolution, which mean they will be a lot sharper for text, 3D graphics, and vectorial art. However, developers will need to include higher resolution bitmap images to make the app look perfect.
Like the iPhone 3GS and the iPad, the display has an oleophobic layer that makes it easier to clean.
The main camera
The new iPhone has a bigger sensor for the main camera. It's backlit and has bigger lenses too. Instead of having a higher resolution, however, the sensor maintains the same 5 megapixel count. They are bigger dots, however, so it has a higher ISO—or sensitivity to light. That means that you would be able to take better photos and video in low light conditions, and your pictures will look a lot better.
The camera also has a LED-based flash, which works both for photographs and video. To focus, both for photographs and video—you just need to tap on the screen.
The video conferencing camera
In the front, there's a video conference camera, with standard VGA resolution. This camera will be used with third-party applications, as well as Apple's own video conference solution.
The new iPhone 4 has a gyroscope built-in. This means that it can track movement with a very high precision, much higher than the built-in accelerometers in the previous iPhones. It's 3-axis, so it's capable of detecting pitch, roll, and yaw. Couple with the accelerometer, you have 6-axis motion sensing.
• Like the iPad 3GS, the new iPhone uses the new micro-SIM standard.
• It has an additional microphone on the top used for noise cancelation.
The new iPhone 4 comes with iOS 4, a new moniker for the iPhone OS. The biggest new feature is, of course, selective multi-tasking, Apple's way to multitask some application features without consuming too many resources and battery power.
The new iOS 4 supports Apple's Retina display using resolution independence. This means that applications will automatically get scaled for the new resolution, but looking sharper, not pixelated. That includes typography, 2D vector graphics, and 3D graphics. However, developers will have to include higher resolution images for buttons or other screen controls (something that many have already, since this was already exposed in the last WWDC).
However, the biggest feature of the new iPhone 4 is probably video calling, thanks to its front camera. Apple calls it FaceTime, and it works iPhone 4 to iPhone 4 over Wi-Fi—at least for 2010. Apple claims that in the future it will be available over 3G.
The iPhone 4 can use both cameras for video calling, so you can broadcast what is in front of you to another iPhone 4.
iMovie for iPhone
The new iPhone 4 will be able to use a new editing software from Apple: iMovie for iPhone. It comes with 1,500 new features.
The new iMovie for iPhone works on even 720p high definition. You can use it to cut the video clips, add automatic Ken Burns effects for still images and a music soundtrack taken from your iPhone's tunes. After you are done with your movie, you can export it to 360p, 520p, and 720p.
It's a separate application, however, it doesn't come built-in with the iPhone 4.
iBooks will also be available for the new iOS4. Apple claims that the new iPhone 4's 325 pixel-per-inch display will make the books perfectly readable. It will use the same controls as the iBooks application in the iPad.
Price and availability
The Phone 4 is available in black or white and cost $199 and $299 for 16 and 32GB if you are a new user or you are eligible for an upgrade.
If you are an existing iPhone user, the early upgrade will cost you $399 and $499. Without contract, the iPhone 4 is $599 and $699.