Cutting through all the noise

Digital noise. You hate it, right? I hate it too. It must be stopped. But how?

Noise is a result of our technological limitation to developing a sensor that can handle low light. Camera companies are building the best sensors they can, and they are getting better (see the Nikon D3) but they still have limits. If you turn up the sensitivity of the sensor too high, you’ll see that limit in the form of digital noise. A speckled, multi-colored mess of pixels overlaying the image (mostly in the dark portions of the image).

Film had these same limits, but it resulted in grainy images, which could have some charm to them. Noisy images have no charm. They look terrible. So, while we are certainly improving the cameras ability to handle noise at higher ISO’s, we’ll still get some if we venture to those limits, and beyond.

The limit of your particular camera will depend on the model, but todays cameras start seeing noise typically at around 800 ISO. If you need to shoot higher than 800 ISO (or whatever you’ve determined is the limit of your camera), and your image becomes noisy, you want to do your best to minimize it. Some cameras will have a “High ISO Noise Reduction” feature you can turn on to help out. It’ll kick in at a predetermined ISO setting to reduce noise, at the cost of a longer wait time to write the image to the card. You might even have the equivalent for long shutter speeds, which also cause noise.

The second phase of noise handling is done on the computer. Running all my images through a good noise reduction filter is usually my first step in post, even if it’s minimal noise (in which case, minimal reduction will be applied).

In Photoshop you’ll find your noise control under Filter > Noise > Reduce Noise. In Lightroom you’ll find it under the Detail tab in the Develop view. In Optics Pro it’s under the Enhance tab under DXO Noise. Most good photo editors will let you adjust and manipulate a noise filter. Some, however, don’t have that feature – so you may want to look at a program just for noise.

Noise Ninja from PictureCode, who tout their software as “the gold standard for image noise reduction”, has a fantastic noise filter, but it unfortunately has no RAW file support (at least not yet). Still, if you want to see what Noise Ninja is capable of, here’s a portion of the same photo without the Noise Reduction (I’ll let you guess which), and the other is with it.

There are other options as well, including Neat Image and ASF GEM. In the battle of photographer versus noise, you do have some tools to help you out, it’s just a matter of finding them.