Improved high ISO performance in today’s cameras has changed the way I shoot. I just spent my morning in our backyard bird blinds photographing in low light. How low? Murky enough light that I was using ISO 12,800 on my D6. Yep, and getting terrific files. If you would have told most photographers a few years ago you could get decent images at 12,800 they probably wouldn’t have believed it. But it is true. My normal high ISO benchmark is 6400. I shoot hundreds of images each morning in our blind at this ISO, do a little noise reduction, and the images look great.
So how to reduce noise? First, let’s talk about what causes noise. The biggest variable is light. When you are photographing in low light, you need to gather more light for a correct exposure. You might shoot wide open, say F4 on your long telephoto, and use as low of shutter speed as possible. And then you are left with adjusting ISO. Increasing your ISO will increase the signal to noise ration on your sensor, making it able to capture more light. But with the increase in signal (the good part) you also increase the noise (the bad part). Most cameras can handle ISO of 800 without too much noise. Sensor size matters, bigger is better. On my full frame D6 I can shoot at ISO 6400 with great results, and even shoot higher at 10,000 and above. But remember, as you increase your ISO you will start to loose image quality. Sharpness, color fidelity and contrast all start to suffer as you push your ISO higher.
Noise comes in two main types. Luminance noise is the gray speckles you see in your image, obvious in shadows. And color (chroma) noise shows up as specs of color throughout your image. You may have heard about thermal noise, often referred to as hot pixels. These are obvious bright spots in your image often from long exposures caused when your sensor heats up.
To reduce noise, you have a lot of things that can help. First, shoot at as low of an ISO as you can. Next, for long exposures, try using your in-camera noise reduction. You may have both a setting for long exposures as well as a setting for standard shooting. On my D6 I have both Long Exposure NR and High ISO NR. I use Long Exposure NR for star trails and exposure times longer than 5 seconds. I leave my High ISO NR setting to Normal, but may go to High when I shoot at very high ISOs. Next, get your exposure right. Noise shows up in shadows very quickly, and opening up shadows during editing often will only amply the problem. If you correctly expose your image, then you are reducing the need to correct any under exposure.
Then there is noise reduction in the computer. Both LrC and PS have sliders that allow you to reduce noise. And after reducing noise, you loose some sharpness, so you need to bump sharpness back up. There are other third party plug ins that reduce noise too, but let’s just cut to the chase. Topaz DeNoise AI is way above the rest. They just updated their software, and it is even better.
DeNoise AI takes a look at the entire photo, and determines what is noise and what is detail in your image. The advanced AI math behind this program renders incredible results. And unlike PS and LrC, DeNoise not only reduces noise, but also adds and maintains sharpness in your image. You don’t have to estimate how far to pull the sliders, just drop your image in the program and it does the work.
One thing I really like about the Topaz DeNoise is it applies three different noise reduction actions, and you can compare the results. In the image above, I can decide if I like Low Light better than the DeNoise action. The program also allows you to use a brush to mask areas in the image. You can add multiple images at once for batch processing to reduce noise in a group of images. And the program works on RAW files as well. With all the low light/high ISO wildlife shooting I am doing, I use Topaz DeNoise almost daily. This is one plug in that is so much better than nursing sliders along in LrC. Just let DeNoise do all the work for stunning results.
This junco is from this morning, shot at ISO 12,800. I just did a quick run through Topaz DeNoise, and the results are amazing.