When it comes to noise reduction, you always have two goals. First, obviously, you want to get rid of any digital noise in your picture. But secondly, you want to preserve detail. These often work against each other because increasing noise reduction often leads to a loss of image detail, but if you focus on preserving the detail then you may end up with a noisy picture.
So what can you do about it? Different people have different methods, but for me, there is a good, better,... more