How to make your iPhone shoot in JPEG again after updating to iOS 11
If you own an iPhone 7 or newer with iOS 11, you are probably shooting HEIFs instead of JPEGs without even realizing it.
JPG
Pixelmator now works with HEIF images & integrates with Photos on macOS High Sierra
HEIF images take half the space while preserving the same quality as JPGs. If your shoot HEIFs on your iPhone, you can now edit them in Pixelmator on your Mac.
How and when to choose between HEIF/HEVC & JPEG/H.264 media formats in iOS 11
iOS 11 support the efficient HEIF and HEVC codes that keep you from running out of storage but you can still share your photos and videos as good ol’ JPG and H.264 files, here’s how.