see also:

• Affinity Photo image editor
• OnOne (On1) portraiture retouching workflow
• Tutorial fixing teeth and eye color
• create realistic lipstick

• Affinity Photo requires you to “Develop” your Raw files first - set WB, etc here.
• NOTE if you wish to do your “capture” initial sharpening step within the Develop persona:
  • go to the Details Refinement section under the Details tab
  • according to AP, this is just an Unsharp Mask Filter affect and the % value of the radius equates to how many pixels so 100% = 100pixels radius
  • you may wish to add a small amount of sharpening here, perhaps radius 5% and amount 40%, or even less for portraits

• this is a subtle degree of sharpening to address softening introduced by the anti-aliasing filter if there is one on the camera
• you should be able to see a difference when zoomed in at 100%, but not when viewing the whole image fitted to the screen
• apply an Unsharp Mask filter with a radius of around 0.3 and a factor of 0.3-0.5

• Affinity Photo tutorials -Frequency separation to remove blemishes and smooth skin
• Amy E Osborne's Headshot retouching

• https://youtu.be/UUAn9XBS7qQ
• YouTube tutorial:
  • create a duplicate layer of your background layer
  • select the duplicate layer to create the two frequency layers (high freq contains details while low freq contains the colour information) via Filters: Frequency Separation
  • decide on what radius to use - the smaller you choose, the smoother the skin will become, the larger the radius, the more natural it will be - aim for some texture to still be visible in the low frequency layer
  • click apply and the duplicate background layer will now be replaced by a high freq and a low freq layer
  • select the low frequency layer and add a Gaussian blur via Filters: Blur: Gaussian and have it reasonably blurry, perhaps a radius of 20px
    • but we want this blur only applied to skin, so with the low frequency layer selected, hold Alt key and click on the mask icon to add a black layer mask
    • now with the layer mask selected, paint in over the skin avoiding shadow edges, hair, nose edges, etc (press B for paintbrush and ensure white is selected and set hardness to 0%) to apply the low freq blur to the skin only - if you need to add black toggle black and white using X
    • adjust the degree of skin smoothing by clicking on the low frequency layer and altering its opacity
  • right click on the top layer and select Merge Visible to merge the layers and then select the new merged layer
• https://www.youtube.com/watch?v=n2IGUIrYY68
  • as above but uses the stamp tool to remove blemishes in the high frequency layer before touching the low freq layer
  • then select the low freq layer to correct areas of color or tonality variation
    • use L to select the Lasso tool with a Feather of around 50px and then select the area you wish to correct
    • then add a Gaussian blur to this selection, apply, then Cmd-D to de-select the selection
    • select other areas (such as shadow edges or highlights to soften them) and then you can apply the same Gaussian blur effect to that selection by Cmd-F
  • remove blemishes using the Inpainting Brush with Hardness set to 100%
• Affinity iPad version example
• Olivio Sarikas example of male face
• Removing lighting hot spots via frequency separation
  • Using the Mixer Brush on the copy of the Low layer to bring in the missing tone and color
  • Working on the copy of the High layer to add in the missing skin texture

• color correct skin

• this is sharpening to focus the viewers attention eg. the eyes and perhaps mouth and eyebrows

• YouTube tutorial
  • select Live Filters:High Pass Filter
  • increase radius setting until the parts you want to sharpen become visible eg. eyes, eyebrows, mouth
  • set Blend mode to Overlay
  • close the dialog box
  • select the High Band filter layer and invert it by using Ctrl-I
  • press B to select the paint brush and ensure color is set to white so you can now paint white onto the areas of the face that you want sharpened with the high pass filter (press X to change to black so you can paint out areas you didn't want sharpened but accidentally included)
  • if you need a strong effect, duplicate the high pass filter layer using Ctrl-J then adjust intensity by using the opacity slider for the layer
  • apply more sharpening for web sites which apply compression to your images and less sharpening for printed images

• you need more sharpening if:
  • web sites which apply compression to your images
  • small prints
  • printing on matte paper
  • low printer resolution
  • viewing distance is further away from print
• consider using OnOne Resize or Nik Output Sharpener instead of Affinity Photo's Unsharp Mask which requires more trial and error and complexity

• save image with a new name to reflect the new size
• resize it via Document > Resize Document to a size 1.6x the final pixel size
• apply the sharpening to the resized image using the Live Unsharp Filter with perhaps 0.3 Radius and 0.5 in Factor
• merge the layers by selecting both layers and right-click and choose Merge Visible
• now resize to final image size via Document > Resize Document
• again apply the sharpening to the resized image using the Live Unsharp Filter with perhaps 0.2-0.3 Radius and 0.5 in Factor
• the image may end up brighter than the original so consider adding a Levels adjustment layer to address this + 1.05 brightness
• the image may end up less saturated than the original so consider adding a HSL adjustment layer to address this by adding +5 to +9 saturation
• see https://www.photography-raw.com/how-to-sharpen-your-photos-for-optimal-results/
• review the sharpening and adjust the opacity for the top most Unsharp Mask filter layer
• export to jpeg

• YouTube tutorial
  • on the menu select Document: Colour Format: LAB 16 bit
  • select Live Filter: Unsharp Mask
  • set the radius and factor to desired level of sharpness
  • return to sRGB by select Document: Colour Format: sRGB