I just bought a macbook pro and have a dell pc with photoshop on it. I use a canon 10mp slr and when uploading photos into pc with photoshop average file size is between 7mp-9mp using large jpeg fine settings. Why when I upload to macbook pro and aperture are my file sizes between 2mp-and 4mp? I am a little concerned because I do a lot of enlargements. Most of my finished file sizes in photoshop end up being around 12mp, after doing some layers. Any ideas i'm a litle stumped.