This is a REALLY nerdly question, but... I'm getting a new super-compact camera to replace my old 4-megapixel one that died. This is a "throw it in the pocket and take my son to the park" thing. Everything available is 8-10 megapixels with no increase in sensor size, so I *know* about the noise problems. I'm hacked off about it but what can I do.. Question: If I set one of these high-MP cameras to its 4-megapixel mode (as I'm ok with that and don't have a big hard drive), does a camera use ALL of the pixels on its sensor and then average the pixels out down to 4mp, or does it hit "every other" pixel on the sensor and take that? In other words, would the noise issues in individual pixels at 10mp be effectively smoothed out by shooting in a lower mode?