4:3 is the largest file size. I use 16:9 mode which is good for laptop and TV screens. I have a 16gb card and can record hundreds of pictures. I use Center focus on 'P' mode a lot. There are other settings specially the creative ones and it's actually fun to use. Explore and experiment with the camera and you'll find it's very versatile. The only negatives I find is that the focusing doesn't do well on low light/contrast and manual focusing is a pain. For low light situations I use manual mode instead. Lastly, enjoy your vacation and take in the moment other than pictures.