How do i import photos from a Lumia phone to El Capitan's Photos app?
You can use this soft :

http://www.microsoft.com/en-us/mobile/support/product/nokia-photo-transfer-for-mac/


  Use this software to transfer photos and videos between your Nokia
  Lumia phone with Windows Phone 8 and your Mac computer or laptop with
  Mac OS


After that you can import your photos (stored on your computer) by using Photos.

Photos -&gt; File -&gt; Import ...