When I want to edit them on my Mac running OS X 10.11.6, I cannot even view these HEIC format images. The pictures taken with my iPhone 7 on iOS 11 are uploaded to my Mac in HEIC format. Want to download HEIC photos from iPhone to Mac and edit these HEIC files. While the thumbnail appears, an alert exclamation is all I get. Photos captured on my iPhone 7 will not transfer into Photos on my iMac. I use El Capitan and iPhone 7 running iOS 11.