The Curse of All Files and All Images and False Duplicates

Recent versions of OS X have included some very broad smart searches in the Finder. These are called things like 'All My Files' or 'All My Images'. These are simply lists. The list all the files (or images). But this is a horribly crude measure of the resources on your Mac, because it offers no context about these files and what they are for or do.

On the iPhoto forum we frequently see posts from people reporting issues with duplicates. A person goes to All My Files or All My Images and sees several versions of their photos. Not surprisingly, they think they have found a nest of space wasting rubbish.

However, an iPhoto Library can contain multiple versions of a photo, none of which are duplicates and all have very important uses. Your Library will contain the Master image - that's the copy that came from your camera. If you have edited it (or if it a Raw image) then there will be a Preview. That's used for sharing to emails, word processors and so on. That exists so you don't have to tediously export every single time you want to send an email to Grandma. Then there are various thumbnail versions of the image used for display in the iPhoto window. These are the larger ones in Events and Photos view, and the tiny ones in Edit view. Each and every version is required for the application to work. They are not duplicates - for a start, they're all different file sizes - but different versions geared to different purposes.

So: If you see duplicates in the iPhoto Window then you may have a duplicate issue. If you see what look like duplicate images in All My Files or All Images, then you do not have a duplicate issue.

From this two things flow: First: Ignore these two searches. They are too broad and it's very easy to damage and lose data interacting with them. Second: Never delete anything whose purpose you do not understand.