Transfer photos without backing up the iPhone
Try AirDrop.

It's a very simple way to transfer any kind of files (not just photos) between devices. Just select the pictures, right-click them, select Share > AirDrop, and pick your iPhone. Make sure it's unlocked, or it won't show up.

Important note: To use AirDrop between Mac and iOS, your mac needs to be from 2012 or later (but not the mid-2012 Mac Pro) and running OS X Yosemite (10.10) or later, and your iPhone needs iOS 7 or later.