If you have a newer Mac that supports AirDrop, you can wirelessly backup photos and videos from your Mac to your iPhone or iPad.
- Click the photos you'd like to transfer in the Finder window.
- In a new Finder window, click AirDrop from the side menu.
- Make sure your iPhone or iPad is unlocked and awake.
- Drag your selected files to the iPhone or iPad option in AirDrop.
- Depending on your Apple ID, you may need to tap Accept on your iPhone or iPad.
From there, all selected photos and video will transfer. This works better for small batches of images, rather than your entire photo library; if you want to transfer all your Mac's photos, you may be better off using iTunes.