Wednesday 4 November 2020

Mastering Noise Reduction in Lightroom: The Essential Guide

The post Mastering Noise Reduction in Lightroom: The Essential Guide appeared first on Digital Photography School. It was authored by Simon Ringsmuth.

Shooting at a high ISO is a great way to retain control over other exposure parameters such as aperture and shutter speed while still getting a usable image.

However, even today’s digital cameras still produce noise and grain when shooting at values like ISO 6400, ISO 12800, and beyond. While an ISO 6400 photo is never going to look as clean as a photo taken at ISO 100, you can use Lightroom noise reduction to clean up your high ISO images.

Mastering noise reduction in Lightroom involves a few tradeoffs. But it’s a great solution for people who need the flexibility of shooting at high ISO values while still getting great results.

Mastering noise reduction in Lightroom infant
Nikon D750 | Nikon 85mm f/1.8G | 85mm | 1/500 sec | f/1.8 | ISO 6400

To understand how to use Lightroom noise reduction, it’s important to learn a little more about ISO.

In a nutshell, ISO is a measure of a camera’s sensitivity to light. When shooting with film, each roll has a single value and cannot be changed until you use up all your exposures and put in a new roll. Digital photography, on the other hand, lets you alter your ISO any time you want.

Higher ISO values let you use smaller apertures or faster shutter speeds because your camera produces a brighter exposure. As a result, you don’t need as much light coming through the lens in order to take a picture. This means that you can use a smaller aperture, faster shutter speed, or both. (Or you can use Auto ISO and let your camera figure out the rest.)

The tradeoff is that increasing your camera’s ISO inevitably leads to noise being introduced to the picture. (Digital noise is kind of like the static you might remember seeing on old television sets.) High ISO shots aren’t as sharp, and colors aren’t as vibrant, thanks to noise. But if shooting at ISO 6400 means you can use a fast shutter speed to avoid motion blur, then it’s generally a tradeoff worth making.

Mastering noise reduction in Lightroom man portrait
Nikon D750 | Nikon 85mm f/1.8G | 85mm | 1/90 sec | f/4.8 | ISO 6400

The best of both worlds would be a high-ISO shot that retains the color and sharpness of a low ISO shot. Unfortunately, that’s not actually possible (at least not with current technology). But mastering noise reduction in software such as Lightroom gives you a great deal of control over reducing high-ISO artifacts while keeping as much detail as possible.

A closer look

The effects of high ISOs aren’t always visible when photos are downsized for the web. To really see what happens at high ISOs, and to understand how to clean it up, you should look at images up close.

Here’s a zoomed-in view of the above image; you can now see the effects of shooting at high-ISO values:

Mastering noise reduction in Lightroom portrait close-up
Up close you can see the speckled background on the left and the lack of definition in the eyebrows. These are just some of the effects of shooting at ISO 6400. Noise reduction settings are at their default values: Luminance 10, Detail 50, and Contrast 0.

Lightroom lets you remedy these ISO artifacts, at least partially, through the Detail panel in the Develop module.

There are two types of noise reduction available: Luminance and Color.

Luminance is the most common form of noise in digital photography and refers to the slight speckled variations in brightness from one pixel to the next. You can see this most clearly in the brown background on the left side of the above photo.

Color noise is often obvious at very high ISO values like 25600 or greater. It looks like random splotches of color scattered around the brightest or darkest portions of an image. In modern digital photography, color noise isn’t nearly as much of an issue in most instances. Most of the time you won’t need to use the Color, Detail, and Smoothness sliders. For most practical purposes, it’s best to stick with luminance noise reduction adjustments.

Lightroom noise reduction sliders mastering noise reduction

To access the noise reduction sliders, click the Detail panel in the Develop module. The noise reduction sliders are grouped with sharpening adjustments because these often go hand-in-hand. Boosting noise reduction can have a smoothing effect on your images which can be somewhat mitigated by adjusting the sharpening sliders.

Getting detailed

When working with luminance noise, there are three sliders to adjust:

  • Luminance
  • Detail
  • Contrast

Luminance is a measure of how much noise to remove, while Detail and Contrast give you finer control over the effects of the noise reduction.

You might notice that Lightroom automatically applies a small amount of noise reduction to every RAW file by default. This is generally a good starting point because RAW files, due to their unprocessed nature, inherently contain more noise than in-camera JPEG files. And it’s almost always recommended to remove some of that noise even if just a tiny bit.

To start the noise removal process, move the Luminance slider to the right. The farther you go, the more pronounced the noise removal effect will be. I generally don’t push it past 50, but your settings will depend on your image and your personal preferences.

Mastering noise reduction in Lightroom portrait close-up
This is the same image as above, but with Luminance set to 50. Notice how the background is much smoother, as are the cheeks. However, the eyelashes have lost much of their sharpness.

After adjusting the Luminance slider to your liking, use Detail and Contrast to bring back parts of your image that might have been lost by the noise reduction algorithm. Move the Detail slider to control the threshold at which the noise reduction starts to kick in. This can help retain some of the details in your image but end up leaving some of the noise intact.

Mastering noise reduction in Lightroom portrait close-up
Bumping the Detail slider up to 80 brings back some of the sharpness around the eyelashes and other areas of the face.

As you adjust the Luminance slider, you will see some parts of your picture get muddy, almost like a layer of petroleum jelly has been smeared across the shot. Use the Contrast slider to bring back some of the high-contrast parts of your image that are most affected by the Luminance slider.

Mastering noise reduction in Lightroom portrait close-up
Moving the Contrast slider up to 40 helps mitigate a bit more of the effects of software-based noise reduction. However, the more you use the sliders, the more processed and artificial your images will look.

As with many aspects of photography, there is no single correct answer for how much noise reduction to use in Lightroom. Some high-ISO images will look fine without too much tinkering, while others require more drastic measures. Mastering noise reduction isn’t about finding one solution that works for every image. It’s about understanding how to use the editing tools to create the best possible outcome for any given photo.

Low ISO versus noise reduction

To really understand how Lightroom noise reduction works, it helps to look at some comparisons of images so you can see the results for yourself.

The following images show different versions of the same scene; one base shot is taken at a very low ISO, while another is taken at a high ISO. I then apply varying degrees of noise reduction and display the results.

I took the first image at ISO 100:

test scene
Nikon D7100 | Nikon 50mm f/1.8G | 50mm | 1 sec | f/8 | ISO 100

Here’s the same scene shot at ISO 6400 for comparison:

test scene
Nikon D7100 | Nikon 50mm f/1.8G | 50mm | 1 sec | f/8 | ISO 6400

When resizing images for the web, some of the issues with shooting at a high ISO are difficult to notice. However, a few artifacts do stand out, such as the muddiness of the solid blue radio toy, and a clear lack of definition in the intricate parts of the ball maze on the left.

For a closer look, here are 100% crops of each image:

test scene crop
A 100% crop of the original ISO 100 image. Note the fine detail in the cactus and the overall clarity of the picture.
test scene crop ISO 6400
A 100% crop of the original ISO 6400 image. Colors are washed-out and subtle texture is obliterated. Note that the green paint lines at the borders of the white lines are completely gone.

When looking at these images close-up, it’s clear that the ISO 6400 photo is noticeably worse. However, if shooting at ISO 6400 or greater will give you the ability to get the shot you want, then it’s a tradeoff worth making.

High-ISO shooting becomes even more practical when you learn to eliminate some of these issues in Lightroom. Using the noise reduction options won’t fix a high-ISO image entirely, but it can go a long way toward cleaning things up.

test scene with noise reduction
A 100% crop of the ISO 6400 image with these adjustments applied: Luminance 80, Detail 60, and Contrast 55. While the ugly noise artifacts have been smoothed out, the image still isn’t as rich and detailed as its low-ISO counterpart.

Mastering noise reduction in Lightroom isn’t just limited to moving three sliders in the Detail panel. It’s best paired with other adjustments such as Texture, Clarity, Contrast, Saturation, etc. There is no one-size-fits-all preset to magically make your ISO 6400 images look as good as ISO 100 images. But with a little work, you can bring back some of the punch and brilliance of your originals.

test scene noise reduction and edits added
A 100% crop of the high-ISO image with previous noise reduction edits applied along with the following: Contrast -15, Shadows +34, Blacks -35, Texture +42, and Saturation +22.

Noise reduction isn’t a cure-all, and it won’t resurrect parts of the image that were never captured to begin with. In the ISO 6400 shot above, no amount of software-based noise reduction can bring back the green paint along the white lines that were clearly present in the low-ISO image.

But careful use of the tools available to you can go a long way toward making a messy picture more than usable.

Mastering noise reduction in Lightroom test scene
Nikon D750 | Nikon 85mm f/1.8G | 85mm | 1/250 sec | f/2.8 | ISO 6400. The sun was setting and I needed a fast shutter speed, so I chose to shoot at ISO 6400 and was able to adjust it in Lightroom. My clients loved the results.

Mastering noise reduction in Lightroom: Conclusion

Mastering noise reduction in Lightroom isn’t a science; each image is different and your own preferences matter most of all. Shoot some test images at ISO 6400 or higher, then see what you can do to clean them up using the tools available to you.

You might be surprised at how much latitude you have when editing. The more you experiment, the more skilled you will get.

And soon you’ll be transforming your photos from noisy messes into near-masterpieces.

The post Mastering Noise Reduction in Lightroom: The Essential Guide appeared first on Digital Photography School. It was authored by Simon Ringsmuth.



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