How to delete images from Photos

Readers ask about how to clear out space used by multimedia in the Photos app through deletion and optimization.

photos for el capitan

Apple rolled out Photos for the Mac earlier this summer.

Credit: Apple

Jay Bolton finds his iPhone, with 700 or so photos, has filled up its memory. He wonders after trashing other images why he’s still got a full phone, and doesn’t want to turn to iCloud Photo Library to help.

I’ve seen many times that iOS devices will retain as much as gigabytes of old items—especially in the Messages app—that it doesn’t purge when it’s no longer needed locally or has been deleted. The only way to restore this missing storage is perform a backup and restore, which wipes the phone. This dumps allocated but unneeded files, though it’s a time sink. (Apple’s guide will walk you through it.)

You can also connect an iOS device to a Mac and use iPhoto, Photos for OS X, or even Image Capture to transfer images, then delete them after they’re moved over. You can also opt for third-party cloud storage services, like those offered by Amazon and Google, to back up images and videos and store reduced-size versions or previews on your phone.

When does optimization kick in with Photos?

Terence Nickolette asks:

Any idea how much space would be saved by using iCloud Photo Library with Photos for OS X and choosing to Optimize images? I have a 45GB referenced library I’m now using with the new Photos app with the photos on a external drive. My system hard drive is 500GB with 75GB of free space.

If I move the referenced library to the cloud and the Photos app on my Mac becomes the Photos default library, will it take up the full 45GB with photo files, or can I expect to save a lot by having those photos optimized?

Apple doesn’t provide any public guidance about how optimization works, but moving the library won’t immediately provide any relief. A 45GB library will remain a 45GB library until such point as whatever threshold is reached where OS X (and iOS with that feature enabled there) starts dumping any locally stored full-resolution original image files.

But you don’t have to manage this. Once you move the library over, as long as the files have been synced to iCloud Photo Library, they’ll be deleted from your local machine without your involvement. I expect a 45GB library could be as little as 2GB to 5GB after optimization.

If you don't want to trust iCloud Photo Library to keep full-resolution versions of your images and never ever have a failure that loses those non-optimized versions you’ll need to pick at least one Mac to set up to keep the original images. I discuss this issue in a different Mac 911 column, "How to be sure Photos for Mac stores full-resolution images."

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