Join Jan Kabili for an in-depth discussion in this video Reducing digital noise , part of Learning Lightroom 4.
Lightroom can help you to reduce digital noise in a photo, those small specks that you may see in a photo, particularly when you shot in low light with your camera's ISO set relatively high. Under the histogram, you can see some of your Camera settings. These are the settings with which I shot this photo, and as you can see, the ISO was way up at 3200 for this night scene in Venice. You won't often notice digital noise when you zoomed out on a photo in Lightroom to this extent so that you can see the whole thing in the Document window. To evaluate noise you want to zoom in to the One to One view.
I'm going to do that by going over to the Navigator panel and clicking 1:1. When you zoomed in this far, the photo is larger than the image window, so if you want to see a particular part of the photo you have to pan the image around in the window either by clicking and dragging in the window or to get a particular area by using the Navigator panel. I'll click inside of the white box there and I'll drag the part of the image that I want to see down here. Lightroom's controls for handling digital noise are located not in the Basic panel, which we've been working in so far, but in another panel, the Detail panel, over in the column on the right.
In order to make room for the Detail panel, I'm going to close my Histogram panel by clicking the triangle on the top right of the Histogram panel. I'll do the same with the Basic panel and then I'm going to click the arrow to the right of the Detail panel to expand that panel. And I'll scroll down so you can see all of that panel. Up here at the top of the Detail panel, there is a preview that you can use instead of this large Image window, if you want a smaller preview of what you're doing while you're reducing noise or sharpening a photo. If you don't see this preview at all, click this black arrow in the Detail panel.
If you want to get to a particular part of the image, in the Detail panel click this target symbol and then in the image click on what you want to see inside of that preview. The Detail panel has both sharpening and noise reduction controls. You want to reduce noise before you sharpen that image so that you don't end up sharpening the specks of noise. So, we're going to talk about noise reduction in this movie first and then sharpening in the next movie. There are two flavors of digital noise and so there are two parts of the noise reduction area of this panel.
One kind of digital noise is Color Noise, which shows up as blobs of color in an image, and the other is Luminance Noise which shows up as grey scale specs in the image. And, you can see the Luminance Noise here in all these little specs. You can't see the Color Noise right now because by default, the Color slider is enabled and set to a value of 25, and in this case that's sufficient to do away with the Color Noise. If that's the case in a photo of your own that you're working on, you can just leave the color and its detail slider at their defaults and go on and deal with Luminance Noise.
But I do want to show you what Color Noise looks like so I'm going to take that Color slider and drag it all the way back over to the left. Now if you look closely, you can see the pink and green and blue specks in this image and that's Color Noise. The way to reduce that Color Noise is to drag the color slider to the right. So, I'll just drag that over to the right until I no longer see that Color Noise. Now sometimes, dragging the color slider to the right can cause a small loss of detail or maybe color saturation at color edges.
And so there is a Color Detail slider here that you can use to bring back some of that detail and saturation at fine color edges. I'm going to zoom in closer so you can see what I'm talking about. I'll zoom in to 3:1 by clicking that here in the Navigator panel and then I'm going to drag in the image over here to the edge of this model's hair where there is a blue flower. Now again, I'm going to take that Color slider and drag it all the way over to the left. So now there is no color noise reduction. Keep your eye up in this area as I drag the Color Noise Reduction slider to the right and you may see a little bit of loss of blue saturation here in the edge.
So, to try to bring that back, I'll drag the Color Detail slider over to the right. And that does bring back a bit of that detail but, this is all very subtle. These are minor differences. So again, with regard to Color Noise, the best way to go is to set your screen to a 1:1 view and then just check to see if you can see any Color Noise with the Default settings of the Color slider and the Color Detail slider. And if you can't, just leave things as they are and go on to deal with Luminance Noise.
Now even if there is no Color Noise there is likely to be some Luminance Noise in an image shot with a high ISO like this one. The way to reduce that is to take the Luminance slider and drag it to the right. Keep your eye in the image as I do that. And you can see that I've smoothed away those grey scale specks of Luminance Noise. But at the same time, I've blurred the image. I'll drag back over to another part of the image so you can see that there as well. And I'm actually going to go out to 1:1 view so we can see this better.
Now, once again, I'll take the Luminance slider back to where it was at zero, you can see the Luminance noise. Watch what happens when I increase the luminance. Everything is smoothed out. The grey specks go away but I've also blurred the colors in this wall and over in this fabric as well. To try to fix some of that blurring and smoothing, as soon as I activate the Luminance slider by dragging it to the right, I get a Detail and Contrast slider lighting up as well. They are no longer grayed out and I can use them. So I'm going to try dragging the Luminance Detail slider over to the right to try to bring back some more detail.
I'll take it way over and yes, I can see more detail here in these white areas and in this fabric but at the same time I've introduced some artifacts which you can see here. So as with many things in Lightroom I'll have to make a compromise. I'll back off a bit on the Detail slider. To get to a point where I've done away with most of the Luminance Noise but I still have some of the detail that I'd lost. Another way to deal with the blurring and smoothing of the Luminance slider is to drag the Contrast slider over to the right.
Now this is very subtle but, if you look at some of these fabric right here, as I drag the contrast slider over to the right, you may see it get a little bit darker in the dark areas and a little bit lighter in the light areas. So again, that's how it was. And that's how it is when I drag to the right. So Lightroom does a pretty terrific job of handling digital noise that comes from the camera sensor, particularly on RAW images shot in low light at a high ISO. Once you've minimize that noise using the Color and Luminance noise sliders, you're ready for the last step in our photo processing work flow which is also done right here in the Detail panel as I'll explain in the next movie.
- What is Lightroom used for?
- Importing photos and videos
- Organizing your library with collections
- Adding keywords and ratings to photos
- Cropping and straightening photos
- Adjusting color and white balance
- Reducing digital noise
- Working with video
- Making changes with the Adjustment Brush and Graduated Filter tools
- Sharing photos on Facebook
- Printing photos