How to import photos from iPhone to a Mac with OS X El Capitan? I started my Photos app on the Mac by pressing the Option key and then clicking on the Photos app icon, so that I can choose an external hard drive to store photos.

However, the Photos app is showing "No Photos" in the Import tab, when there are about 70GB of photos.  The "Photos" tab, however, show a lot of photos, but they cannot be imported into my Mac.

I am running the latest iOS 9.2.1 and Mac OS X El Capitan.  How do I make this work?
I would recommend Image Capture. It's a bit less advanced than the new Photos, but in my opinion it's simpler.

Open /Applications/Utilities/Image Capture.app to begin.

Next, select which directory you would like to import the photos to from the "Import to" dropdown.

Cmd ⌘A to select all, and hit the "import" button OR hold Cmd ⌘ and click to select a few to import. Either way, the selected images will be imported into the specified directory.

To delete all these imported photos from the exporting device (ie iPhone), Cmd ⌘A and click on the "delete" button (looks like a prohibition sign).

Side note: if you wish to rotate an image, click the "Rotate" button (looks like an arrow) and all selected images will be rotated.