How to download an icloud album on my iphone

Hello,

I've got an iCloud 200 Gb storage plan.

I use the optimize storage setting both on my iPhone with iOD 9.0.1 and on my Mac Book Air with Photos runinng on the latest version of Yosemite

I'd like to know how to download quickly an entire iCloud photo album to my iPhone or my Mac (with Photos) in order to view the picture in full resolution. Just one album.

Thank you