For starters, the 5s uses a new, five-element lens that Apple designed specifically for the new iPhone. This new lens offers an f/2.2 aperture, a 15-percent-larger area than the iPhone 5's lens, and 1.5-micron pixels—larger than those on the iPhone 5 and other smartphones.
The phone also includes a new dual-LED True Tone flash that Apple says is the first of its kind on a phone or a standalone camera. One flash is cooler white, while the other is amber with a warmer color temperature. The phone monitors ambient light and then fires the two flashes together to match that light. Together, Apple says, the two flashes provide more than 1000 unique light combinations, for flash lighting that's brighter and more natural.
But iOS 7 also includes a bunch of software specifically designed to take advantage of the improved camera hardware. For example, before you take a photo, the phone automatically adjusts white-balance and exposure to create a tone map for better highlights and shadows; it also performs auto-focus matrix metering for improved sharpness. When you take the photo, the phone actually takes multiple images, analyzes them in real time, and then shows you what it thinks is the best one.
The 5s also includes image stabilization in software: In situations—such as low lighting—where you'd normally end up with blurry images, the phone takes multiple photos with a single shutter press, and then it blends them together into a single, sharp image. And a new burst mode captures ten full-resolution frames per second for as long as you hold down the shutter button. But unlike most burst modes, on an iPhone 5s, the phone automatically filters out bad shots to show you only the "best" ones. (You can choose others manually, if you like.)
When taking video, you can capture 720p video at 120 frames per second, slowing it down later for true slow-motion video. (You can do the editing in your favorite video app, or you can choose, right in the Photos app, which section of the clip to view in slo-mo.) And Panorama mode now lets you adjust exposure as you pan.
Many times during the iPhone event, Apple pointed out the advantages of making both hardware and software, combining them to best take advantage of both. The iPhone's camera features are one of the best examples of this philosophy in action.
So, this fingerprint-sensor thing, Touch ID: how does it work?
It's a capacitance-based (as opposed to optical) scanner built into the iPhone 5s Home button. The "capacitance" part means that instead of taking a visual scan of your finger or thumb, the scanner detects minute differences in electrical charge caused by a fingerprint's whorls, loops, and curves.
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