How to delete photos from devices but keep in iCloud
I can't seem to find any info on this for High Sierra. I have an iPhone and iPad that I would like to keep connected to iCloud for current photos. My iCloud photos library is huge and I don't want all of it on the devices. Is there any way to delete older photos and videos from the devices but retain them on iCloud? I don't need photos from 2015 on my phone but want to stay connected for newer ones. I'm invested in the "i" family but getting frustrated that I'm running out of space because I took too many pictures at that house party in 2016. TIA
iPhone 5, iOS 10