Understanding Noise Reduction Inside Lightroom

Hi and welcome to my blog. Today, at a members request, I am going to explain Noise Reduction inside Lightroom. First off, noise is visible artifacts that degrade image quality and is caused by many things. One of the most common causes of noise in poor exposure, in particular under exposure. Another common cause of noise is high ISO settings. As you turn up the ISO you turn up the noise, it’s that simple. There is a cure for noise at high ISO’s, and that is good lighting. You can shoot at a very high ISO if you are shooting in good light. But that’s kind of a catch 22 isn’t it? If you have good light then there is no need to use a high ISO. I didn’t make the rules, I just know what they are. So moving on…

There are two types of noise in digital imagery. The first type is called luminance noise, and it is represented by grey pixels in your images. The second type is chroma (color) noise. When dealing with noise in post, whether it’s in Lightroom or any other software package, it’s always a balancing act. You must balance between noise and a soft blurry image. A quick tip, you must learn to give and take. There is no magic number that will fix every image and you must make judgments based on several factors. First, what is the final intent for the image?  Is the final image going to go on the web as a thumbnail or be a 30×60 print that is to be viewed at nose distance on the wall? When you answer those questions, life gets easy or more difficult, but at least you know where you stand.

Let me explain the function of the controls in Lightroom’s Detail, Noise Reduction Menu

Luminance This slider reduces luminance noise.
Detail This controls the threshold of the luminance slider.
Contrast This controls the contrast of the luminance slider. The higher the value the more it preserves contrast, but only in the luminance noise affected areas.
Color This slider takes care of color noise, it turns the RGB noise pixles in to grey pixels much like luminance noise. For that reason, I always deal with this first. But only when I am ready to correct noise in my images.
Detail This slider is the threshold for color noise. It helps protect the color detail at the edges, a micro contrast control for color noise affected areas in the image.

I made a video to help you understand what is going on. Remember, dealing with noise is always a give and take situation. Consider the final use for the image and it just might help you get through the process of noise correction much faster. Thanks for taking time to visit today. I hope you all have a wonderful day. Sincerely, Thomas Shue