Taking good digital photos in low-light situations is a tricky task. Many photos taken at night suffer from a phenomenon called “noise”. No, I’m not talking about audible sound; by noise, I mean the appearance of an unsightly grain throughout your photos. Noise is an unfortunate side effect of using ISO to force your camera’s sensor to capture more light. Fortunately, we can deal with noise in Adobe Photoshop.
In order to test the various methods of noise reduction, I will be using the following photo:
Fig. 1 - Original Photo
Method 1: Dust & Scratches Filter
Photoshop’s Dust & Scratches filter does a decent job at removing small amounts of noise from photographs.
- Open your photo in Photoshop
- Click Filter → Dust & Scratches
- Increase the Radius in order to reduce noise.
This method has a trade-off: as you increase the radius, your photo will begin to soften. The key is to find a middle ground with enough noise reduction, without softening your photo too much.
Fig. 2 - Using the Dust & Scratches filter
The dust & scratches filter did a pretty good job cleaning up the sky and clouds, but there is still some noticeable noise in the bottom half of the photo. Going any further though, would make the photo extremely soft and blurry.
Method 2: Noise Reduction Filter
Photoshop’s Noise Reduction filter is also good at removing digital noise from photos.
- Open your photo in Photoshop
- Click Filter → Noise Reduction
- Adjust the sliders in order to reduce noise
As with the Dust & Scratches filter, the Noise Reduction filter will also soften the details in your photo. The softening appears slightly different, and in my opinion, is often times favorable over the softening that occurs from using the Dust & Scratches filter.
Fig. 3 - Using the Reduce Noise filter.
The Dust & Scratches filter also did a pretty good job cleaning up the sky and clouds, and also left a bit of noticeable noise in the bottom half. Any more reduction, and this photo would also appear too soft and blurry. You can see how both of these filters create softness, but each one does it in a slightly different way.
Method 3: Noise Ninja
Noise Ninja is a Photoshop plug-in that is specifically designed to … wait for it … reduce noise in digital photos. I have not used Noise Ninja, but am including it here due to the shear number of people I have heard singing it’s praises across various digital photography forums.
Noise Ninja has a license fee, which ranges from $35 - $80. This may turn off some, but Noise Ninja’s sample images alone appear to be worth the price tag.
Bonus Method 4: Use a Different Camera
If you use a point & shoot digital camera, you might not be aware of what ISO is because your camera adjusts it automatically. Here’s your crash course in ISO: Adjusting ISO means to adjust the light sensitivity of your camera’s sensor. A low ISO setting will produce sharp photos with little noise, but requires a large amount of available light. Low ISO settings work best in daylight. High ISO settings are required for low-light environments because more light is able to be captured. The side effect of a high ISO is noise.
The amount of noise present in a photograph at a given ISO setting depends on the quality of the camera’s sensor. A moderately priced compact digital camera will be severely affected by noise at high ISO settings. A more expensive DSLR (e.g. Canon Digital Rebel) will operate much better in low light, but still produce an undesirable amount of noise at high ISO settings. Finally, an amateur or professional grade DSLR (e.g. Canon 5D, Canon 1D) will feature excellent low-light performance with very little noise.
