There are many ways to reduce noise in post when you’ve perhaps shot an image with too high of an ISO in a low light situation. With cameras going up to the hundred thousand ISOs these days, grainy images may some day become almost obsolete. Even though my Canon 5D Mark II has some expanded range high ISOs, I don’t like to take it too much further past 3200 ISO hand held.
Though we cannot remove noise completely from an image, in the cases of too much noise (or grain), you can use Lightroom, which Pye explains in this detailed post here, third party plugins or Photoshop to help minimize the grain and bring back some of the image quality. In the 4 minute Photoshop Playbook video below, Bryan O’Neil Hughes explains a few ways you can effectively reduce noise. He goes over three methods that work well using Camera Raw, smart sharpen or image size to take the image from this: