The quality of your photos depends on the size of the sensor inside your camera: A larger sensor can pick up more light, which gives you better shots, whether it's broad daylight or the middle of the night. A bigger, better sensor also effectively gives you more options in terms of depth of field. If you want that effect where the subject is in focus and the background is wonderfully blurry, a big sensor will help. Of course, with a larger sensor, the price of the camera goes up accordingly. Here's the terminology to keep in mind: Full-frame sensors are the largest (the sensor is the size of a 35mm piece of film), followed by APS-C, 1.5-inch, and then Micro Four Thirds. You'll often find 1-inch sensors in high-end compacts. It's worth nothing that the sensors don't measure 1-inch in real life, but the designation is based on an archaic standard traced back to video technology.