This may have been answered elsewhere, but if so I can't find it! On my 256GB SSD, I have two photos libraries. The original iPhoto library/package is 3.51GB, last opened in April this year, and I have the newer Photos library/package which is only 1.7GB. I'm a bit short of space, and if possible would like to clear out the older iPhoto library. Is it truly dead, or does Photos still use the content? Or did all the content get copied into the Photos package? I was sort of assuming that the lower size was due to the lower resolution, with the full res stuff up in the cloud. But I'm not familiar enough with Mac innards yet to risk deleting all of the photos without some sort of advice!