Step 1: Connect Your External Hard Drive To Your Mac
First, connect the hard drive to your Mac and make sure it shows up in the Finder’s sidebar. Copy something to the hard drive from the desktop just to make sure it works. If it doesn’t then it might not be formatted to use with a Mac (most external hard drives aren’t). If that’s the case, you’ll need to first reformat the hard drive to FAT format.
Step 2: Connect Your iOS Device To Your Mac
The first thing you need to do is connect your iPhone or iPad to your Mac using the USB to Lightning connector you got with your device.
Step 3: Launch Image Capture
Image Capture on Mac is one of the most underrated utilities. To launch it, search for “Image Capture” using Spotlight search (using Cmd + Space shortcut).
After you launch it, find your iOS device in the left sidebar and click on it.
You can either use the keyboard shortcut Cmd + A to select all or just individually check mark all the images you want to import.
Step 4: Select Destination
By default, photos will be imported in the Pictures folder. Click the drop-down, and select “Other”.
Now select the folder in the external hard drive as a source.
Step 5: Click Import
Click the “Import” button and wait until the transfer is done. If the external hard drive is USB 2.0 spec, and you have a lot of photos, this could take more than just a couple of minutes.