) how much space you have on your computer, and how much time you will really spend editing the pictures.. If you use iPhoto, use JPEG (iPhoto does, however, have good support for RAW, so it's really up to. what program will open a jpeg file free program to reduce jpeg file size jpeg file program So, I vote RAW, but only if you don't mind photos taking up 15-20MB or so (I think). what program wi..