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Limiting Noise Reduction in Useful Ways
As with any other correction in the Color page, noise reduction can be limited using HSL Qualification or Power Windows. This means you can focus your efforts on reducing noise in the most problematic areas of an image (for example, in shadows and background regions), while sparing elements that you don’t want to affect (such as faces or better-lit areas of the image).
Furthermore, you can use Spatial NR in lieu of Blur operations to perform a subtler form of complexion smoothing, using the HSL qualifier or a window to isolate an actor’s skin tone for targeted noise reduction.
Controlling the Order of Operations for Noise Reduction
You can apply noise reduction at any point in your image processing tree using a dedicated node. If you have an image with noise that you think might be enhanced by whatever corrections you need to make (increasing the contrast of underexposed clips often increases whatever noise is within an image), there are two approaches to noise reduction:
— Apply noise reduction at the beginning of a node tree: This lets you pre-emptively eliminate any noise before it becomes a problem as a result of whatever adjustments you’re planning to make. The result can be smoother, but you may also notice that the edge detail within the image is a bit softer.
— Apply noise reduction at the end of a node tree: The alternative is to make your adjustments first, and then apply noise reduction in a separate node afterwards. In this case, you may find that the noise reduced regions of the image aren’t quite as smooth, however the edge detail within the image may be visibly sharper as a result.
— Apply noise reduction to only one color channel of an image: Using the Splitter/Combiner nodes, you can also apply noise reduction to only one color component of an image. If you’re grading a video clip with a noisy Blue channel, this can be a way to focus noise reduction where it’s needed. Isolating a single color channel for noise reduction is also possible using the
Channels selection when right-clicking a node. By selecting the specific channel numbers in this node corresponding to your color space (RGB, YUV, LAB, etc.), you can limit the noise reduction operation to the appropriate channels only.
NOTE: If you apply noise reduction and make color adjustments within the same node, noise reduction is processed first, followed by color adjustments.
NOTE: If you apply noise reduction and make color adjustments within the same node, noise reduction is processed first, followed by color adjustments.
NOTE: If you apply noise reduction and make color adjustments within the same node, noise reduction is processed first, followed by color adjustments.
Neither result is universally better or worse than the other. Which is preferable depends on the image you’re working on, and the type of result you’re looking for (you might prefer some shots to be a bit softer, while you’d like other shots to be a bit sharper). The real point is that the node-based image processing of DaVinci Resolve lets you choose which technique works best for you.
— All three Noise Reduction controls are available via knobs on the PRIMARIES, NOISE REDUCTION control group on the Center panel.