Apple unveils iPhones 6S, 6S Plus with '3D Touch'

Following Apple's typical pricing system, the base-model iPhone 6S will cost $649 without a two-year carrier contract. Prices for the iPhone 6 and iPhone 6 Plus will be knocked down by $100.

Apple has unveiled its updated smartphones, the iPhone 6S and iPhone 6S Plus, giving its large-screen handsets a new pressure-sensitive display with '3D Touch' gestures.

Apple's Chief Executive Officer Tim Cook took to the stage in San Francisco's large Bill Graham Civic Auditorium to announce the new iPhones along with a series of updates to the company's other products including the iPad Pro and Apple TV.

"What we have to show you today is really awesome, While they may look familiar, we have changed everything about these new iPhones," CEO Tim Cook said. Along with unveiling the iPhone 6S and 6S Plus, Apple revealed a lot of other gadgets including a revamped Apple TV and the iPad Pro.

Apple live streamed the event. This year's iPhone is Apple's off "S" year.

That means Apple keeps the basic design of the device the same but adds other features to attract buyers, like the Siri digital voice assistant in the iPhone 4S and the TouchID fingerprint reader in the iPhone 5S.

A marquee feature for this year's iPhone 6S was expected to be the Force Touch technology used in the Apple Watch, a pressure-sensitive display that responds to various types of touches.

The company instead unveiled '3D Touch', a feature that appears to have the same capabilities.

The iPhone 6S and 6S Plus will also support LTE Advanced, a faster version of 4G currently supported by EE and Vodafone in the UK and rival manufacturers Samsung and LG.

The new iPhones will also have Wi-Fi calling that can be used when no mobile phone signal is available, which currently supported by EE in the UK.

The standout feature of the new iPhone 6S and 6S Plus is the new touchscreen technology called '3D Touch'.

First introduced with the Apple Watch as Force Touch and then the Apple MacBook trackpad, the pressure-sensitive touchscreen can detect various types of tap. From a single traditional tap to heavier presses, each gesture can produce a different interaction with the smartphone.

"We've fitted brand new glass, the strongest in the industry X-ion and we've improved on multitouch with '3D Touch', a tremendous breakthrough in interacting with the smartphone," said Phil Schiller on stage.

The new 4.7-inch 6S and 5.5-inch 6S Plus, which are the same size as last year's models, will be available for pre order starting Saturday and will go on sale from September 25 in the US, UK, China, France, Japan, Australia among others.

The phone will be available in 130 countries by year's end.

Following Apple's typical pricing system, the base-model iPhone 6S will cost $649 without a two-year carrier contract. Prices for the iPhone 6 and iPhone 6 Plus will be knocked down by $100.

New gestures, peak and pop, allow users to lightly touch to get a preview of media or other item such as an email – a peak – and press longer and harder to pop out the content for a full view.

The gestures can also activate an activity menu to jump to particular places within an app.

The new A9 processor will have 70 per cent faster performance and 90 per cent faster graphics, but will also boost battery life in conjunction with Apple's new version of the iPhone's operating system iOS 9.

The pressure-sensitive touches are accompanied by Apple's Taptic engine, first introduced with the Apple Watch, vibrating with short, tap-like feedback.

Apple has improved the Touch ID fingerprint sensor to make it twice as fast for unlocking the device and authenticating purchases with Apple Pay.

It has also improved the 8-megapixel camera of the iPhone 6, fitting a new, more powerful 12-megapixel sensor on the back.

The new addition is capable of shooting 4K video and takes on Samsung and other rivals with their 16-megapixel, feature-rich cameras. Apple's iMovie app on the iPhone 6S can also edit video in 4K. 

The front-facing selfie camera has also been improved with a new 5-megapixel sensor, Apple's first upgrade to the front camera since the 1.2-megapixel sensor of 2012's iPhone 5.

The phone will use the screen to mimic a camera flash for front-facing photos.

The new iPhone can also shoot so-called Live Photos, which capture video and sound along with a photo for 1.5 seconds each side of the capture event, very similar to HTC's Zoe feature introduced with its One M7 smartphone in 2013. Following the apparent bending of the iPhone 6 Plus within user pockets,

Apple has used a new stronger aluminium for the iPhone 6S and 6S Plus frames.

The "7,000 series aluminium" was first introduced with the Apple Watch Sport and is 60 per cent stronger than standard aluminium alloys, according to Apple.

The stronger aluminium should help prevent the iPhone from bending, but could also increase the smartphone's scratch resistance.

The iPhone 6S and 6S Plus will also be available in a new rose-gold colour, the pink gold will be sold in addition to the gold variant which was first introduced with the iPhone 5S in 2013, primarily to appeal to the Chinese market. In another notable change, Siri can be activated via voice for the first time, using the command "Hey Siri."

That will allow users to ask the digital assistant to play music or make a phone call, even while washing dishes or preparing a meal.

In older models, Siri can only be activated by pressing the phone's home button.

The new feature helps Apple catch up to other devices, such as the Amazon Echo speaker and many Android phones, that can already be activated by voice.

Also, owners of newer models of the iPhone can upgrade to the new iOS 9 operating system starting September 16.