sharpness in a portrait

When I use the sharpness on a portrait with the deconvolution (between 0.90 and 1.20) it appears a kind of grain, it is necessary to reduce the strength of the adjustment to make it disappear. So it lacks a bit of sharpness. As for the unsharp mask, it seems to me to be less efficient.

What do you use on a portrait to sharpen?

Quand j’utilise la netteté sur un portrait avec la déconvolution (entre 0.90 et 1.20) il apparaît une sorte de grain, il faut réduire la force du réglage pour le faire disparaître. Alors il manque un peu de netteté. Quand au masque flou il me semble moins performant.

Qu’utilisez-vous sur un portrait pour faire la netteté ?

I usually sharpen just the important parts, like eyes, using a mask, and leave skin unaltered. Or possibly blur skin areas slightly with e.g. Contrast Equalizer (again, with a mask).
The demosaic-sharpen option within Diffuse Or Sharpen seems to sharpen nicely.

can you share an example and describe a bit more the intended usage of the output? I.e. are you downsizing or using the full resolution image? If the latter, at what size are you printing (or showing the picture) and what is the viewing distance? All these factors matter quite a bit IMHO in determining what is a “good” strategy for sharpening.
That said, you can also use the texture boost tool to increase the perceived sharpness. As a starting point, you can try using a strength of about 0.15 and detail scale of about 0.10 and tune from there.


@Valmy , was it tagged “Art” from the start?, if so I missed that, sorry, I was quoting darktable functions.

My approach for portraits is similar to Andrew’s:

  1. apply basic sharpening (RL deconvolution by default), and adjust the Contrast threshold if the image is noisier than average (image shot with high ISO for example);
  2. in the Local editing tab, apply some Local contrast (actually I decrease the local contrast by lowering the contrast curve) on a Color similarity mask that is targeting the skin tones;
  3. Occasionally I apply some Smoothing (still in Local editing) using the Guided mode and play with the 3 sliders.
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it does not matter

I rarely print an image in the photo club exhibition format, namely 30cmX40cm or 30cmX45cm (4/3 or 3/2).

I often make photo books at Blurb. The images are a maximum of 18cmX24cm printed.

I pay attention to the quality of the images that I send to the printer because the print returns are not always at the top.


J’imprime rarement une image au format d’exposition en club photo à savoir 30cmX40cm ou 30cmX45cm (4/3 ou 3/2).

Je réalise souvent des livres photos chez Blurb. Les images font au maximum 18cmX24cm imprimées.

Je fais attention à la qualité des images que j’envoie chez l’imprimeur car les retours d’impression ne sont pas toujours au top.

Thanks for the context. The “grain” you see is the symptom that the deconvolution radius is too large. If you are not happy with the sharpness after reducing it, you can try using texture boost as outlined above. If you decide to try, let me know how it works.