This all depends on how you want to use your camera and how long you want data preserved. If you want to record continuous video in HD you'll want a high capacity card. If you just want to record during motion detection events a smaller card may hold weeks worth of video. Or if you just want to save snapshots, a small card is fine. I have 3 cameras with SD cards.. one is 2GB (in an SD camera), one is 4GB, and one is 16GB (each in HD cameras). The DCS-2332L is a HD camera, so the larger images will consume more storage.