One of your problems is you're shooting through double glazing, it doesn't matter how good your lens is if you shoot through a window, its like fellas that spend a fortune on realy good lenses and then throw a shitty cheap UV filter on the end , it defeats the point of shooting with good glass !! you shouldnt have any problems with iso at 200, i think another problem with compact cameras is they have whats called a digital zoom, which isnt really a proper zoom and crops away at the image , when ever you crop an image you get degredation, i think thats as much your problem as anything