I have had several cameras over the years, and thus have ended up with many different photos with the same file name. I realize that this is not a problem within iPhoto, as the program itself can tell the difference between file names even if they are the same. However, I'm getting ready to back up my photos to an external hard drive. I'm realizing that if I have two photos of the same name, one will overwrite the other when transferred to the external drive. Also, I have a non-Mac "cloud" back-up service that I pay monthly for. Right now I'm realizing that it has probably happened there as well, and I'm likely missing pictures there. I am aware of the method to change the photo titles in iPhoto, but since this does not change the file name it will not suit my needs. How do I get around this problem? I have thousands of pictures so I cannot deal individually with each picture. I was hoping to do a Batch rename of files (using the date/year as a prefix, maybe Oct2014-1, for example). Then I could do batch file name changes from this point forward as I upload pictures. But, if iPhoto does not allow me to change the filename, I don't know how to solve the problem. Any help is appreciated. Thank you!