I just got a D600, a lovely camera. I am curious that when I use 4GB cards with raw files with the camera set up to use the card in the second slot as overflow that the capacity for each card is showing 74 frames. With those same cards in my Nex-7, the capacity is 158 frames. Both are 24MP cameras and looking at the files sizes from each camera, they are about the same, 25MB. I format the cards in their respective cameras when using them. Why the difference?