


Today’s Question: I have been using Photoshop for over 20 years and early on decided to avoid using the denoise functionality because of potential loss of detail. However, recently I have been experimenting with this function and have been pleased with the results in many challenging situations, so I assume this functionality has been upgraded over time. However, I still am concerned about what the process does to the source file, as it seems to apply destructive edits. Am I correct?
Tim’s Quick Answer: No, none of the adjustments (including Denoise) in Camera Raw, Lightroom Classic, and Lightroom, will alter the original raw capture. And it is true that Denoise has gotten significantly better with recent updates.
More Detail: I suspect any concern about Denoise altering the original raw capture is the result that a recent change from Adobe enables Denoise to be applied without having to create a DNG file as part of the process. In effect, Denoise is now simply another of the many adjustments available in Camera Raw, Lightroom Classic, and Lightroom.
One of the key features of raw processing software is that it does not alter the original raw capture. Rather, the raw data is processed with the adjustment settings you’ve specified, to generate new pixels that would typically then result in a new image file. The raw capture remains unaltered. The adjustment settings are preserved in an XMP “sidecar” file. This can contribute to making it appear that the raw capture was modified, because if you open the raw capture again, you’ll see that all prior adjustments (including Denoise) are already in effect.
Rest assured that your raw capture remains unmodified. You could, for example, simply reset all adjustments to revert to the original image, or make a second copy of the raw capture (without the XMP file) and open that to start from the default settings.