So while ISO is a quick and easy solution to low-lighting situations, once the number gets to a certain point you will probably start seeing a significant increase in digital noise. You can mitigate this by:
1. Using a Wider Aperture
This lets in more of the light that’s already available, allowing you to keep your ISO number lower. Keep an eye out for your depth of field though, as aperture is the deciding factor in your image’s level of focus.
2. Selecting a Slightly Longer Shutter Speed
This is another way to maximize available light and avoid raising your ISO number. Unfortunately, longer shutter speeds can generate heat, which can cause color noise. That’s why you should also be:
3. Watching Out for Heat During a Shoot
A high ISO number isn’t the only thing that can cause noise. Heat (especially heat from those long shutter speeds we just talked about) can introduce color noise, even if your ISO number is ideal. Overheating isn’t usually a problem for modern cameras, but if you are experiencing consistent issues with noise, it will help to note heat sources that could be avoided and see if the noise levels improve when you do so.
4. Knowing Your Camera’s Native ISO
This is the best setting for your camera in terms of maintaining detail and preserving quality. That doesn’t mean this is the only setting that will give you good results, it’s just the best possible one for the equipment you’re using. (Find your camera’s native ISO in your camera manual or by doing a quick Google search.)
5. Shooting in RAW
To allow yourself as much flexibility in post-processing as possible, capture as much information as you can in-camera. RAW files contain a lot of (wait for it) raw information that can be brought forward during the editing process. Skies that are slightly blown out can be walked back, details can be rescued from their muddy depths after a low-light photo shoot, and noise can be managed with a lot more finesse. Shooting in RAW isn’t always necessary but it’s advisable in low-light situations where you’re already at risk for noise.
Sorry, crop sensors! A full-frame sensor can use available light more efficiently while capturing less noise. Although it’s not necessarily a reason to upgrade if you weren’t going to already, it’s a definite plus.
The Ugly: Fixing Undesirable Noise in Post-Processing
While the best way to avoid noise is to prevent it, that’s just not always possible. But even if you don’t include (or add) noise on purpose, you can still take steps to make it blend well enough that it won’t be the first thing viewers notice about your photo. Noise reduction technology can’t work miracles (not yet, at least), but it has become very sophisticated and there are a lot of different ways to go about it. We’ll talk about some of those in this final section.
Something to Know Before You Begin
Chromatic noise and luminance noise get “fixed” in different ways. Chromatic noise gets desaturated a little at a time, which can affect the saturation throughout your image. Sometimes the only way to really fix it is to desaturate the entire image and embrace it as black and white. Luminance noise gets smoothed, which can affect the sharpness throughout your image. So keep both of those things in mind as you use one of the following methods to remove or minimize noise in post-processing.
We’ll start with the method that is most user-friendly but affords the least amount of control. When you open your image in Lightroom, go into the Develop module. When you scroll down the Develop menu a bit, you’ll come across the Detail options. It will look something like this: