Why Are RAW Files So Noisy? [4 Reasons]

Most photographers prefer to edit their RAW files before converting them to a more widely-readable format. However, some experience times when their RAW files are much noisier than other file formats, such as JPEG. Why does this happen?

Below, we’ll discuss the four most common reasons for excessive noise in RAW camera files. Keep reading to learn what they are and how to combat them!

Why Are RAW Files So Noisy?

Working with RAW files usually allows photographers to make more precise edits to their photos without compromising quality. However, some people notice that their RAW files have significantly more noise than other formats. Generally, this will happen for one or more of the four following reasons:

  1. The way RAW photos are processed
  2. You used too long of an exposure
  3. Your ISO setting is too high
  4. The way you’ve edited the photo

Below, we’ll discuss more information on each of these four reasons and how you may be able to combat excessive noise. 

1. The Way RAW Photos Are Processed

If you shoot in both RAW and JPEG formats, you may notice that your RAW photo files are noisier than your JPEG files. This is because of the way your camera processes the two different formats.

JPEG images are processed according to your camera settings and rendered before you upload them to your computer. This means things like automatic noise reduction are already done before you even see the photo.

On the other hand, RAW images show you the raw data from your camera. No automatic noise reduction is done, meaning you’ll see more noise in your RAW files than in your JPEG files by default. 

2. You Used Too Long of an Exposure

Longer exposure shots are inherently noisier than shorter exposure shots. If you set the exposure too long, the camera’s sensor heats up and creates noisier shots.

The best thing to do in this situation is to learn how well your camera handles long exposure shots. Shoot a series of photos at different exposure lengths, then check each photo to see how noisy they are. Every camera is different, so your maximum exposure length will depend on your model.

Some cameras offer a built-in feature to combat this, called “long exposure noise reduction.” Turn this feature on if you need to shoot a long exposure photo but want to avoid excessive noise. 

Keep in mind that this feature will increase processing time, so it may not be the best idea if you need to shoot a series of long exposure shots.

3. Your ISO Setting is Too High

Your camera’s ISO setting controls the amount of light your camera lets through the lens. A higher ISO makes your camera more sensitive to light, brightening up darker shots.

Allowing too much light through your lens increases a photo’s noise levels. While every camera is different, noise will generally increase around ISO 1600 or 3200. However, some can handle ISOs up to 6400 or 12800 before the noise levels noticeably increase. 

Shooting at a lower ISO is the easiest way to decrease noise levels in your RAW files. If your photos are too dark at a lower ISO, there are a few things you can try to brighten them up without raising the setting:

  • Open your aperture more
  • Lower your shutter speed
  • Use your camera’s flash

Each technique will allow for a brighter shot without raising your ISO to a higher level.

4. The Way You’ve Edited the Photo

If you notice that your RAW files are getting noisier as you make your edits, it’s probably due to the way you’ve edited the photo. Many adjustments can cause this, including:

  • Increasing brightness. This brightens up any shadows in your photos, also brightening the noise in the shadows.
  • Increasing saturation. This can increase variations in the colored parts of your photo, also known as chrominance noise. 
  • Using peripheral illumination lens correction. This will generally increase the noise in the corners of your photos.

While making some of these edits is unavoidable, be aware of the adjustments you make and check after each to ensure you’re not creating a lot of noise.

In Conclusion

RAW camera files are inherently more susceptible to excessive noise than other formats. This is because they’re raw data from your camera, with little to no processing done before you see the photo. 

Other settings, such as long exposures and high ISOs, can also increase a RAW photo’s noise. Excessive noise may even be caused by the way you edit your photos after uploading them.