I assume your question is about the file size. Then ... - If you shoot JPG, you can choose a smaller file size. - If you shoot in RAW, chances are good you care about details. Then the more information you have the better (within reasonable limits). An interesting idea is a smaller RAW. I read somewhere that Canon has this option. I assume it is easier just to keep the complete info in 24MP file that to devise a way to downsize is to a smaller file (which could be done in many different ways).