Q: How do I get my old photos back from "restore my phone" without losing my new photos I've taken?

We upgraded from iPhone 5 to the iPhone 6 beginning of June and I forgot to do a full restore to my 6 then. Can I still get my old photos from my last backup without deleting the photos I've taken on my 6 since then?? My iCloud didn't have enough memory to back my 5 up so I synced to my computer before switching phones - would that have kept my old photos? Please help!