One of the biggest advantages of digital cameras or DSLR’s over their film counterparts is the ability to switch ISO settings on the fly. ISO is the amount of light that you let into the camera’s sensor and in the days of film cameras this was accomplished with film speed, sometimes called ASA instead of ISO.
So if you wanted to shoot outdoors, you would load a roll of ISO or ASA 100 or 200 and be good to go, but if you then moved into a dimly lit building and wanted to shoot, you needed either a flash on that camera or you needed to have used up that roll of 100 or 200 film and switch to 400 or 800 to shoot well in those conditions.
With the advent of the digital camera, you can shoot outdoors at ISO 100, and then step indoors and with the flip of a switch or wheel, shoot at ISO 800 or even higher like 6400 or maybe even 12,800. The problem is as your ISO gets higher, you get digital “noise” in your photos. Noise is the little dots, speckles or grain look in your image that I am sure most everyone has seen at one time or another. Look at the grainy “noise” in this image I shot indoors at ISO2000.
Some cameras are better at others at handling high ISO, low noise, but at some point even the best of these cameras will end up with noise in your images and it can make the image ugly and unusable. Luckily, Lightroom can help mitigate this for you and make this image useable again.
When you load your images in Lightroom and come across an image that has noise, this is how you can clean it up in the Lightroom Develop Module. The two big noise removal sliders are under the Detail section and called Luminance and Color. In this next image, after some Luminance and Color noise reduction notice the image is much cleaner.
Here is what each does. Luminance: This kind of noise affects the brightness, but not the color, of individual pixels. If you had a picture of a dark grey piece of paper with a great deal of luminance noise it would appear similar to old-school television static with lots of light and dark fuzz.
Color or sometimes called Chroma noise: This shows up as oddly-colored pixels, scattered throughout an image, almost like someone has tossed a handful of red, blue, and green grains of sand at it. Lightroom calls this “Color” noise, but it’s just another term for Chroma noise.
Now, although you can remove considerable noise with Lightroom, you want to make sure you are careful not to use too much noise reduction as it can make the images look fake and give everything a plastic look. A lot of pros will counter some of the effects of the noise reduction by using some sharpening as well for the best results. In this third image, we see a side by side comparison of the before on the left and after on the right.
So you can see Lightroom did a great job of cleaning up the image! Just keep in mind that you don’t want to go too extreme with the sliders, especially on photos of people as you can end up making them look “plastic”, use common sense and remove as much “noise” as you can, but don’t ruin your images in the process!