Today’s Question: How do adjustments in Lightroom (for blacks, whites, shadows, clarity, vibrance, etc.) affect noise? Should noise be dealt with first or last, after all other adjustments?
Tim’s Quick Answer: In general concept, you can make changes to the various adjustments within Lightroom in any order at all, since the order you apply adjustments doesn’t impact the actual effect of those adjustments. That said, it is important to evaluate the impact of one adjustment on another. For example, if you brighten up shadow detail you may need to increase the strength of noise reduction.
More Detail: Lightroom employs a non-destructive workflow for your photos, meaning that when you are working in the Develop module you aren’t actually changing pixel values in your original capture, but rather creating a set of adjustment metadata that is used to adjust the appearance of your photo within Lightroom, and as the basis of the processing for the photo when you export a copy of a photo.
Among other things, this means you don’t need to apply your adjustments in any particular order to achieve a given result for a photo. In theory, for example, you would want to apply noise reduction before sharpening, so that the sharpening doesn’t enhance the underlying noise. In the case of Lightroom (and also with Adobe Camera Raw), it doesn’t matter whether you adjust the settings for noise reduction or sharpening first. All that matters is the final settings established for these controls.
To be sure, if the noise reduction adjustment doesn’t eliminate the noise altogether, other adjustments may make the noise more visible or more problematic. For example, sharpening can serve to emphasize noise in an image, and brightening shadows can make noise more visible in the photo.
Any adjustment that enhances color or contrast, or that brightens up detail in the photo, has the potential to make noise more visible in the photo. But if the noise reduction settings you’ve applied cause the noise to be mitigated adequately, the effect of those other adjustments on any noise that remains will generally be relatively minor.