For the first time in four years, Apple has increased the iPhone's camera resolution. The latest models -- the iPhone 6S and 6S Plus, unveiled yesterday -- now come with 12-megapixel cameras (up from 8 megapixels) and can capture 4K video (at 3840 x 2160 pixels).
What Apple didn't do is increase the amount of internal storage capacity on the smartphones; both iPhone models continue to come with 16GB, 64GB or 128GB of NAND flash memory capacity. Apple did not respond to a request for comment about that move.
At 8 million pixels per frame, one minute of uncompressed 4K video takes up about 5.3GB of storage. And an hour's worth of 4K video devours a whopping 318GB of capacity.
The new iPhone 6S and 6S Plus camera leverages the much faster processing power of the A9 chipset to also offer "Live Photos," which are created through a fast burst of video recording before and after the actual image capture moment, as well as a snippet of audio. All of which also consumes storage capacity.
As 4K is four times the resolution of 1080p (the resolution of 2014's iPhone 6 camera), it's not unreasonable to assume the iPhone 6S and 6S Plus camera will consume roughly four times the capacity of its predecessor.
However, most digital recorders use compression codecs. How much storage capacity is required depends on how aggressive the compression algorithm is applied, "similar to a photo, where an 8MP photo can be very different sizes depending on the JPEG quality set," said Ian Fogg, head of the mobile and telecom team for IHS Technology.
The iPhone 6 takes 1080p video at up to 60 frames per second (fps); according to published tests, video recordings used up about 200MB of storage space for each minute of content, or about 12GB per hour. At four times the resolution, the new iPhone 6S with its 4K camera might require 48GB per hour of video.
Even so, the top-end iPhone's internal capacity maxes out at 128GB -- the maximum offered by smartphones today, according to Fogg. While the iPhone is not the first smartphone to offer 4K video -- Samsung's Galaxy S5 launched with 4K video last year -- it is among the few to offer up to 128GB internal memory and 4K.
While the 16GB models might quickly run short of storage, the iPhone 6S and 6S Plus's mid-range capacity (64GB) is likely sufficient for most users given the price point of the iPhones, said Joseph Unsworth, vice president of research for NAND flash and SSDs at Gartner.
"While rival Android smartphones have offered 4K capture since the Snapdragon 801 models early last year, many of those had only 16GB or 32GB on board storage. And, those that had micro SD cards often included warnings encouraging use of internal storage for speed reasons," Fogg said. "By comparison the iPhone 6S is generous."
Just as important as onboard NAND flash capacity will be the role of Apple's iCloud Drive online photo and video storage service, according to Unsworth.
"While more storage may be needed [internally on the iPhone 6S and 6S Plus], I think this video could be stored via the cloud or may just be deleted as its ephemeral content," Unsworth said.
Notably Apple has raised the amount of iCloud storage available through its service and slashed some prices in half.
As before, users get 5GB of capacity for free; they can upgrade to 50GB for 99 cents per month (previously that entry level only provided 20GB of storage); 200GB is now $2.99 a month (previously it was $3.99); and 1TB of storage is now $9.99 a month (previously it was $19.99).
IHS agreed that in combination with the cloud services, the new iPhone lineup should have no problem handling the additional video and photo content.
In an analysis of the iPhone 6S and 6S Plus, IHS stated that while both Nokia and HTC have implemented similar features, Apple's use of Apple Photos to enable back-up and cross-device cloud sharing makes their "implementation far more elegant."