Image Noise Reduction
Image Editing Tutorial
You might have noticed that under certain conditions, the image acquired with your DSLR has far too much information, thus creating noise and digital artifacts that mar your photo. This is particularly an issue when you're shooting at night and/or with a high ISO in other low-light conditions... it's the downside of attempting to capture an image when the exposure latitude (the difference between the lightest and darkest section) is wide. So Photoshop has the ability, when properly applied, to eliminate a tremendous amount of that noise. Here are a few methods to do it.