This will be a quick and short tutorial today, to show you the benefits of a sharpening mask within Lightroom.
I have had a couple of people ask me about noise in high ISO images and how to maintain details while removing the background noise, so I thought this may interest you. The image above was shot at ISO 1600 and seems relatively noise free until we look a little closer.
As you can see the image above shows a fair amount of noise with the default LR settings. if you notice that sharpening has been applied (as default) to the entire image. This sharpening is wanted around the details such as the eye and the glasses but less so with the background. In this case, the sharpening is actually making our noise problem worse!
We could turn down the sharpening, but doing so would leave the details looking a little soft.
The solution is to apply a mask to the current level of sharpening, but how do we know how much to apply. The answer is simple, although a little hidden.. Holding down the ALT key while dragging the Masking slider displays the mask. As in Photoshop masks, White reveals, Black conceals.
Moving the masking slider so that there is very little white in the background of the image, and plenty of white over the eyes and glasses.
As you can see the noise levels in the background has been reduced as we are no longer sharpening it, yet the eyes are not softened. At this stage we have not applied any luminance noise reduction, so we apply a small(er) amount of noise reduction
The noise levels are now minimal and well within an acceptable range.
Some people will no doubt say why not just apply the noise reduction and not bother with the sharpening mask.. That would leave an image like this below..
As you can see, the original noise levels have been sharpened meaning a higher noise reduction would have to be applied leading to a softening of the whole image.
At screen resolutions, it is not possible to see the difference in the levels of noise, but try this technique out for yourselves when you have high ISO images that need a more intelligent noise reduction.
NB! the ALT key trick also works on the other sliders in the sharpening panel.. so have a play and see what a difference it makes.
I hope you have found this useful and as always, feel free to comment below