I have Canon S5 IS, a decent camera but crappy beyond ISO 400. I want to shoot in low level light and I will not have an option of an external flash or tripod. To get any decent pictures I want to stay at 1/50 or better, but that would mean that I need to jack up my ISO. From my understanding of how image sensor works, would reducing an image size shot with may camera improve the amount of noise present at high ISO speeds? Since there is less information being recorded?