By Tom Stibolt, MD, Mobile Musings Column Editor

Last month, Apple introduced two new iPhones: the iPhone 6 and iPhone 6 Plus. Both phones use Apple’s new 64 bit A8 processor, which is faster and uses less power than the A7 in the iPhone 5 models and the newest iPad. There is also a motion coprocessor that measures activity from advanced sensors, including a new barometer which replaces individual sensors and provides better performance and battery life.

Apple resisted moving to a larger display for the iPhone 5 models, but it is now offering larger displays on both iPhone 6 models. The iPhone 6 display measures 4.7-inch diagonally. The iPhone6 Plus measures 5.5 inches diagonally. Both are LED-backlit widescreen Multi-Touch displays. The iPhone 6 has 1334-by-750-pixel resolution at 326 pixels per inch (ppi) and the iPhone 6 Plus has 1920-by-1080-pixel resolution at 401 ppi.

The phones share an 8-megapixel rear facing camera with ƒ/2.2 aperture, a five element lens and flash. The iPhone 6 Plus also offers optical image stabilization. The camera can record 1080p HD video recording at both 30 and 60 frames per second. There is a slow motion capability that shoots at 120 or 240 frames per second. Video has continuous autofocus and the camera can take still photos while recording video. The front facing camera is 1.2 megapixels and is capable of 720p HD video recording.

There is a fingerprint identity sensor built into the Home button. In October, Apple will also enable Touch ID, a system to use your phone to make credit card payments using a near field communication antenna. There is no need to open an app or even wake the display to make a payment. A subtle vibration and beep lets you know payment was made so you don’t have to look at the phone. Security is improved over using a credit card as instead of using your actual credit and debit card numbers, when you add your card to Passbook, a unique Device Account Number is assigned, encrypted, and securely stored in the Secure Element, a dedicated chip in iPhone.

The phones are manufactured using an aluminum case. The iPhone 6 is 0.27 inches (6.9 mm) thick and the iPhone 6 Plus is 0.28 inches (7.1 mm) thick. Some users claim that the phone can be easily bent, so a case might be a good idea.

Other features are typical for a modern smartphone with GPS, WiFi, Bluetooth and fourth generation cellular capability, though the exact features depend on the carrier. The phones are both available in 16 GB, 64 GB, and 128 GB models. Prices start at $199 for 16 GB, and each sequential memory amount costs $100 more. The 16 GB iPhone 6 Plus starts at $299, and each sequential memory amount costs $100 more.

With the iPhone 6 line, Apple has also introduced iOS 8, which it bills as their biggest iOS release ever. The new operating system requires 4.6 GB of data storage to run. Those with a 16 GB device or less, such as the 8 GB iPhone 4S, will find themselves with very limited space for music and photos. It is a bit zippier than iOS 7 but does not add a lot of new features. The new OS has mostly internal improvements. Within a week of release, an update disabled cellular service on the iPhone 6 models, which was remedied a shortly thereafter with another update. Still, there are likely to be a few more of these hiccups.

One of the improvements is Family Sharing, which allows people within a family to share content they’ve purchased through Apple’s marketplaces. Family Sharing also allows parents to track their kids and their kids’ purchases. There have also been improvements in notifications and messaging. Apple has made a lot of noise about their Health Kit that will allow data to be capture from users’ monitoring devices. The feature has been delayed due to a bug, but it may be of some interest over time.

iOS 8 is available for the iPhone 4s and above, the iPad 2 and above and the 5th generation iPod Touch.