Apple’s iOS 11 update changes the way we capture and store images on our iPhones and iPads. A new default image format HEIF (High Efficiency Image File Format, pronounced “heef”), created by the developers of the MPEG video format, is designed to save storage space whist maintaining photo quality. HEIC is the file format name Apple has chosen for the HEIF standard and files may appear as .HEIF in the metadata of an image.
After 25 years of accepting JPEG as a common image format it is not surprising that an alternative has been developed to potentially surpass and replace it. HEIC makes it possible to store twice as many photos in the same space AND potentially have them look better. HEIC acts as a container for images and audio and Apple uses it to store still images encoded with the HVEC (H.265) video format. This adaptation lies at the heart of Live Photos as multiple images can be saved within container.
Compatibility outside of iOS 11 is, at least for the time being, a consideration. Images convert to JPEG automatically when you need to transfer them to other platforms or social media sites. There are a number of converters on the market already for handling HEIF files on Windows. The HEIC format can be turned off in the iPhone or iPad settings.
Up to now, I haven't had any major issues with the file format and I've opened them in numerous apps and transferred back and forward to my iMac and MacAir devices which are not yet upgraded to High Sierra.
One word of caution is that Live Photos captures a high resolution still image and 1.5 seconds of movie before and after you take the shot. When choosing the new Long Exposure feature, the system cleverly stacks and blends the frames together and produces a great looking motion blur effect (tripod recommended). Whilst the image is more than acceptable for sharing on social media, closer inspection will show that the quality is less than the original still image. This is because the video, albeit high quality, is not at the same resolution of a still image. Furthermore some cropping will take place, in my example the image with the effect was approx 10% smaller. The overall quality was not as sharp or detailed as the original even though a tripod was used.