I can't find my old photos
I have an iMac (since Mid 2010, OS X 10..8.5) and a MacBook air (since late 2010, OSX 10.8.4). I was going to copy all my pictures from the MacBook to the iMac with a hard disk but something about the existing pictures on the iMac appeared so I decided just to paste the album from the MacBook on the desktop of the iMac to avoid any risks of losing my photos. When it finished, I tried to open them but a window saying that iPhoto couldn't open any pictures because they were in a new version of iPhoto appeared. So I decided to download the new version (9.4.3). When it finished, I opened it but the only pictures that appeared were the ones from the MacBook and I can't find the ones that were on the iMac before.I have looked everywhere and I don't know what else to do. What can I do to recover them???
Thank you!