One of the most common image enhancement workflow questions we get over here is…
At what point in my post-processing workflow should I apply noise reduction?
Why, excellent question! This is actually a very important factor in the quality of the resulting image, whether you use built-in Photoshop noise reduction tools or astoundingly good third-party noise reduction software. When to apply noise reduction is one of the most important and most overlooked aspects of effective image enhancement.
The simple answer is to apply noise reduction before applying ANY other adjustments to the image.
This includes JPEG compression, Camera RAW or even in-camera noise reduction, sharpening, exposure adjustments, dodging and burning, “Psychedelic” presets, whatever. See, in order to differentiate between noise and detail, noise reduction software have a very specific idea of what “noise” looks like and what “detail” looks like straight out of the camera. Applying any kind of adjustments to the image confuses the noise reduction software and causes it to give you a subpar result.
Demonstration time! Consider the following thousand words:
The image is very noisy and a little bit underexposed. I processed it a couple of different ways to illustrate the point of this post:
Feel free to click on the images for larger versions. The first version only has exposure adjustments – in this case Levels – applied to it. Oh no noise! 1600 ISO underexposed isn’t pretty.
In the second version, I took the RAW file and first corrected the exposure adjustment and then applied noise reduction. In the final version, I applied noise reduction as the very first step in my workflow before exposure correction. The results speak for themselves – and this was just a simple exposure adjustment!
Next time you really need to get the best results on your noise reduction, keep this in mind: no matter what noise reduction software you use, it’s always important to apply it first. I’d go as far as to turn off the built-in noise reduction and sharpening functions in Camera RAW before you import into Photoshop for best results.
There’s a lot of advice where noise reduction is put at the end of the workflow together with sharpening. Although this may be convenient, if you’re really looking for great results, put noise reduction smack at the beginning of your post-processing workflow before you touch a single pixel.