iCloud transfer of images doesn't retain full quality

Hi

Thanks for your prompt response. It provided some really useful hints. Turns out the the cue was in a setting in iPhone Photos about how to transfer to Mac or PC. I had this set to "Automatic" rather than "Keep Originals". This resulted in larger files when I connected the iPhone with a cable: For photos, it converted from HEIC to JPG, while for videos, it kept the MOV format but exploded the file size. In the browser, when selecting "unmodified originals", I get the native iPhone format.

On another positive note, changing the iPhone Photos setting also resolved anopther issue that I've had for a long time with connection loss during file transfer. Now I'm just transferring everything in native format using a cable connection. I'm less concerned about image quality loss now that I know that the larger files were just created for compatibility reasons on the phone and that the smaller files are indeed the originally captured photos and videos.

Peter