Noise from high ISO can be a pain sometimes. Darktable has several tools to help you get rid of it or at least reducing it. In this week’s video I show you the different tools and how to work with them.
There are however a couple of things to remember that I did not mention in the video. Noise reduction is very processor intensive and has a tendency to slow down the editing quite a bit, since all the edits are recalculated every time you make an adjustment. Therefore it is important to think about when you apply noise reduction in your workflow.
If you do it early on you will have a cleaner image to work with. This will make it easier to set up good parametric masks, but Darktable will become slow. If you leave it to the end you may have not so perfect masks, but Darktable is quicker. So it is a balance you have to find for yourself, also taking into account the power of your computer. If you have a beast of a machine you may not notice much difference, so you can have noise reduction early on without problems.
I tend to do it this way: if it is an easy edit without much work, I just apply the noise reduction early in the workflow and leave it on. If the edit is more complicated, I like to do it quite early and then turn it off, only keeping it on when I set up critical parametric masks. Then I turn it on again before I do final sharpening. If I during the process send the image over to Gimp for some extra work there, then I do noise reduction before the export. In that case I don’t sharpen anything before export, I do that either in Gimp or when I get the image back into Darktable.