Setting up Photo Stream in iCloud

Photos uploaded to Photo Stream are stored in iCloud for 30 days. Your iOS devices keep a rolling collection of the last 1,000 photos in your Photo Stream, in order to make the best use of their limited storage. Since computers generally have way more storage space than mobile devices, all of the photos that are part of your Photo Stream are kept on your Mac or PC, even if you shoot more than 1,000 photos in a month.

Photo Stream supports JPEG, TIF, PNG, and most RAW photo formats. On a computer, your photos will be downloaded and stored in full resolution. iCloud delivers photos to your iOS device (iPhone, iPad, iPod touch, and Apple TV), in a reduced resolution to save storage space and speed up download times. And while we’re on the subject of storage space, pictures in your Photo Stream don’t count against the 5 GB of free storage that you get with your iCloud account.