Noise Reduction Workflow
Today I’d like to demonstrate my method of noise reduction. Noise reduction is a must to clean up digital noise from shooting with a high ISO and there are many programs and photoshop plugins that specialize in reducing noise. However I do not use any of these third party plugins. I use the built-in noise reduction sliders in Adobe Camera Raw in Photoshop CS5. It’s very simple and VERY effective. If you use Lightroom, the process is the same since it has identical controls as Adobe Camera Raw.
I was recently at Disney California Adventure and after sunset we had the most amazing blue hour. Unfortunately I did not have a tripod with me that night so I was forced to shoot hand held. This meant I needed a high ISO at 3200. ISO 3200 on most cameras starts to push the limits and shots can become extremely noisy. One thing that will make your post-processing much easier for shots at such high ISOs is you must nail the exposure. A properly exposed image will be much easier to deal with when trying to clean up noise. Also, any exposure or brightness adjustments in post, especially for an underexposed shot will only make noise worse!
I shoot in RAW which gives me far greater control when post processing and that is especially true for cleaning up noise. I open the shot in Adobe Camera Raw (or Lightroom) and I make my color and exposure adjustments. I do this first because the changes will have some effect on the amount of noise that is visible. Once I get color and exposure set, I switch to the detail tab (third tab from the left) which gives me noise reduction and sharpening controls. The first slider I play with is the color slider. I move the slider to the right until the blotches of color disappear. The key is to move the slider just up to the point where the colored pixelation disappears. For this shot, moving it to 25 was all that was needed. By moving the color slider, the color detail slider defaulted at 50. I rarely need to do anything else with the color detail slider.
Next I work on the luminance sliders which handle the grainy texture associated with digital noise. Some areas in the darker regions of a photo might have white pixels. I move the luminance slider to the right up until the point where those white pixels vanish. You have to be careful with this slider. Too much and the photo loses all detail and looks washed out and watered down. Here’s an example of too much…
The key is to find a good balance between reducing noise and preserving detail. For shots at extreme ISOs the goal is not to eliminate all noise but to get it under control. You’re just cleaning the shot up a bit. To help maintain detail while reducing luminance noise, I also adjust sharpening levels. There is no one setting that works, you just have to adjust to your liking. Clean the shot up, but preserve details in the photo. You’ll notice the luminance detail slider defaulted at 50 like the color detail slider. Just like color detail I rarely need to move the luminance detail slider.
Notice I didn’t get rid of all of the visible noise, but I cleaned the image up some and now I’m ready to open the photo in Photoshop and run it through the rest of my editing workflow. If my workflow has introduced some more noise to the photo, I might run the final edit back through ACR for another round of noise reduction. That’s rare but sometimes necessary.
I hope you find this article to be helpful. There are many third party plugins and programs out there that cost money and can get very expensive. My method of choice is simple and takes very little time using a small but very powerful section of Photoshop and Lightroom. If you haven’t already, give it a try!