If I change the privacy of a photo on Facebook from "Only Me" to "Friends", will my friends get notified about it?
What can I do if I don't want them to be notified?
Changing audience of a photo or post will not notify your friends. Your friend will not get any notification. But once you change the privacy from 'Only Me' to 'Friends', your friends will be able to see that picture. If anyone else is tagged in the photo, then the audience expands to also include the tagged person and their friends by default.
learn more about what audiences you can choose.