Before continuing, let’s set some specific rules down for dealing with standard sharpening:
Perform all other changes (color correction, saturation changes, distortion corrections, etc.) before sharpening.
Save a copy of the corrected, but unsharpened version. (And you’ve already saved a copy of the original, right?)
Use the Unsharp Mask for basic sharpening, as it provides more control than the other related filters.
If submitting to a professional designer, send the unsharpened version, as you don’t know how dot gain may change the amount of sharpening necessary.
If printing on an inkjet printer, error on the side of slight oversharpening.
Try to use a Threshold of 0 and Radius of .5, if possible.
Lab Color Sharpening – Using the Luminosity Data
Some books and seminars recommend converting your document to the Lab Color space (Image->Mode->Lab Color), and then applying an Unsharp Mask to the Lightness channel (Click on the Channels tab in the Layers window and make sure that Lightness is the only channel selected before applying the filter). After you’ve sharpened your image this way, you convert it back to RGB Color (Image->Mode->RGB Color).
The reason for using a technique like this is that sharpening colored edges means that the Unsharp Mask uses the color data to determine how to modify the edge. This sometimes results in minor shifts in color in the sharpened areas. But the changes are small. For example, the small blue area between the pole and the building front in the image below shifts ever so slightly bluer when using the Unsharp Mask on the original RGB (a value of 90, 132, 187 shifts to 107, 153, 210 using Lab Color sharpening, but to 109, 155, 213 using RGB Color sharpening). If you aren’t using color profiles for all of your equipment and attempting to maintain color matching between acquisition and print, sharpening using only the luminosity data is probably overkill, though, as any miscalibration between your monitor and printer likely produces a bigger shift.
If you are minding every last little bit of color change, be aware that changing color space introduces rounding errors in color values (and the error is more severe in 8-bit images than in 16-bit images). That same pixel value I noted before changes from 90, 132, 187 to 90, 133, 188 after converting to Lab Color and back to RGB Color, without making any other changes to the document.
While I’ve never seen a color changed in ways that I found destructive or problematic by rounding or shifting, I have noted very subtle changes in areas of gradated color patterns. At 1000% view I sometimes see a few random pixels shift in sky tones when making these changes. (Best way to see for yourself: make the adjustment from RGB Color to Lab Color and back to RGB Color. Then zoom way in to an area that has a subtle gradation, then use the History palette to click back and forth between the original RGB and the reconverted RGB. If you’re satisfied you’re not seeing any color shifts worth worrying about, then go ahead and use the Lab Color sharpening method.) If you do decide to use the Lab Color method for sharpening, convert to Lab Color and back only once. Rounding is cumulative, so bouncing back and forth between RGB and Lab Color is a no-no!
A better way to sharpen just the luminosity channel without changing to Lab Color is to perform sharpening as you usually would (e.g., using Unsharp Mask), then choose Fade Unsharp Mask from the Edit menu. In the dialog that appears, change the Mode from Normal to Luminosity and click on the Okay button.
Portrait and nature photographers have one thing in common: we hate seeing sharpening artifacts on large blocks of color. Any underlying noise in the image tends to bubble up to visible, and skies or skin tones with too much detail in them don't look as good as gently gradated ones. And if you know what bokeh is (the character of out-of-focus areas) and care about it, you'll be particularly bothered by what happens to noise in out-of-focus areas. Indeed, the first thing I look at in an image to see if sharpening is detectable is the non-detailed, out-of-focus areas. I've seen all kinds of techniques that attempt to deal with the problem of pulling up sharpening artifacts (deselecting the continuous tone areas before sharpening, using history brushes to paint out sharpening in certain areas, etc.). But the following technique is my favorite. Essentially, you build a mask of just the edges in your image, then apply sharpening to the areas under the mask. Here's one set of steps you can use in Photoshop:
Open your image, as usual. Perform all your other corrections on it before sharpening, as usual.
When you're ready to sharpen, click on the Channels palette and create a new channel. This new channel will eventually be your mask. Change it's name to "Sharpening Mask."
Click on the RGB channel for your image.
Select the entire image (Select->Select All).
Copy the entire image (Edit->Copy).
Click on the Sharpening Mask channel you created in Step #2. Paste the image in (Edit->Paste). It'll appear in black and white, but that's what we want, so don't worry.
Use the Find Edges filter (Filter->Stylize->Find Edges) on the Sharpening Mask channel. It'll turn into something that looks a bit like a line drawing. Our next steps will be to tweak this mask.
We want the black to be really black and the white to be really white in our mask, so use Levels to make the adjustment (Image->Adjust->Levels). Move the black point in from the left, and the white point in from the right (the triangles under the histogram). How much you do this is one of the critical choices you'll be making, so take your time, and remember that the black areas are what are going to be sharpened (the white areas won't be sharpened).
We want to hide the actual sharpening of the edges, so we need to make sure there's a smooth transition from white to black in our mask. To accomplish this, use a small Gaussian blur on the image (say 2-4 pixels) (Filter->Blur->Gaussian Blur).
Now we need to tell Photoshop that our Sharpening Mask is just that, a mask. To do that, we need to select the black bits only. Use Select->Load Selection. In the dialog that comes up, make sure that Sharpening Mask appears as the Channel and that the Invert box is checked.
Click on the Layers tab and make the image visible again. You should see the selection created in Step #10 superimposed over the image.
Get the image ready for sharpening. Choose View->Show->Hide Edges (Cmd/Ctrl-H) to make the selection invisible, then choose View->Actual Pixels and scroll the image to an area with which you want to evaluate the sharpening.
Finally, we're ready to sharpen. Select Filter->Sharpen->Unsharp Mask and play with the values. Note that you can use much higher amounts than usual, as the halos tend to fall outside the selected areas. Radius should be a low value (.5 to 1.0), and Threshold should be 0. If you find that the sharpened area is too restrictive, go back to Step 8 and change your mask.
Yes, that's a lot of steps, but you can easily make them into a Photoshop Action (make sure to click on the icon to make Steps 8 and 13 editable during playback). This, by the way, isn't the only way to perform an edge sharpening technique. I've seen at least a half dozen variants on the idea of making a mask for the details, then sharpen only at the mask.
Using Sharpening to Change Contrast
Here's something I hadn't noticed before. Then one day I made accidentally entered some "stupid" values into the Unsharp Mask filter and noticed a change to the image that was interesting. So I did some research. It seems that a number of digital cogniscenti have been using the Unsharp Mask to make slight bumps in image contrast. It's really quite simple to do: just select a low value for Amount (10-25%), a very high value for Radius (200-300 pixels), and a 0 Threshold. This technique actually produces a more likeable contrast boost, in my opinion, than does the Contrast command. Just be sure to save a version of your image before using this technique (it's not undoable at a later date). You also perform this action prior to doing a "real" sharpening.
/From Thom Hogan’s website
Softening Technique for Portraiture and Glamour
Tutorial by William Zavala Introduction
There are many different retouching techniques to achieve similar results, the characteristics of each technique are different in the sense that some are fast and some require many more layers, masks, and more detail/time. I believe there is no bad technique, your choice will be determined by the characteristics of the particular picture and what effect you are going after. Some techniques are very straight forward and ideal if you are looking to process a bunch of pictures, other methods require more attention to detail and would be a problem if you need to process lots of frames of a particular session, but would be perfect for a very special photograph that for example is going to be enlarged, framed and displayed in a special way. In this case a more precise method will give much better results and will allow you to fine tune the processing to the exact requirements. The method I present here has a little bit of both ends, it is not that slow if several images need to be processed but it also allows fine tuning the final result. Since the principles are the same for most retouching techniques whatever you learn and assimilate from this tutorial will be a very good start for other processes you learn in the future. This technique is suitable for general portraiture and glamour, but specifically for subjects with good skin tone that do not require extreme retouching, and where you have a decent scan with good density all over the skin areas.
General procedure and comments
I am aware that people with varied knowledge on Photoshop will read this tutorial, so for the sake of simplicity for advanced PS users I will enumerate the steps first without detailed description, after this I will go step by step and with images explaining most of the process.
The key for a successful retouching and softening in portraiture and glamour is to work based on selections, this means that you have to work a selection for all the skin areas and sometimes also make more selections for the background, hair, eyes, lips, etc, depending on how much time and detail you are planning to put on a particular picture, so the first advice is to ALWAYS save your selections, especially if it took you more than 30 seconds to make the selection, time is valuable and you do not want to spend more time than needed repeating selections that were not saved, it is very rare to have a perfect selection on the first attempt, normally they need fine tuning, this is the reason PS offers more than a dozen selection tools. Working through selections will give your work a more professional look and save you time on the long run.
How many times we have seen pictures where blur was applied to all the image and it just looks out of focus, this is because not all areas of a portrait need the same amount of softening, evidently not two photographers will agree on how much is too much, but at least selections will allow you to achieve the results YOU think are the best for your pictures. The procedure should work the same for color or b&w pictures, personally I find that b&w needs a little more effect than color pictures, but we will fine tune this at the end. Some people like the softening effect over the hair too, if you are one of those be sure to include the hair in your working selection.
It is very important to work the retouching/softening after you have resized to the final print size or monitor resolution/size, sometimes you can have unpleasant surprises if you process and then resize, same as with sharpening, by the way, leave sharpening as the last step if you are planning to do so. This technique is a subtractive method, you will be decreasing the softening by stages, and creating different densities of blur with each pass, which is exactly what we need in a portrait. The original layer (background) will never be altered by this method, this is a good thing if you don't like your results you can just throw away the new layer and start again. Its always better to work with high resolution, for this example I will be working with a file that is 1552 x 1248 (21.5 by 17 inches aprox.) at 72 pixels. Keep this in mind if you plan to use similar parameters in your own pictures, or modify accordingly.
If your picture needs luminosity correction, go ahead and work on that first, you will need adequate luminosity to evaluate the best results.
Make a selection that includes all skin areas, and save it as a new channel.
Load the selection and apply feathering according to the resolution and size.
Create a new layer from the selection you just made. (Ctrl+J)
Apply a good dose of Gaussian blur to the new layer, even if you think it is too much, we will be talking about this in the detailed steps.
Select the eraser from the tool box and set opacity to 50%
Select a large brush that covers most of the selected area in one pass and apply the eraser to selection, remember, just one pass over the image selection.
Select a smaller brush a little smaller than the size of the eyes and erase again now in the areas of the eyes, lips, jewelry, and any other important feature.
Now reduce the opacity of the new layer to 50% and evaluate the softening, sometimes it is needed to erase more of the softening in some areas, only you can evaluate this. Depending on your taste you can fine tune increasing or lowering the general effect by changing the layer opacity.
Use your favorite sharpening method, it is better if you apply sharpening after the process is done.
When finished just flatten and save as jpg or any other format that you require.
Note: You can click on any image to open a window with a larger version
The picture needs to have correct luminosity before you start, this is like when we use soft filters or soft lenses in real photography, the more light the more pronounced the softening will look, so it is better to use levels, curves, or whatever method you prefer to make any corrections to the image before starting the softening.
We have to make a selection for all the skin areas first, these are the areas of the portrait that 80% of the time will need to have a soft effect to help reduce the detail, like open pores, wrinkles, acne scars, etc. My favorite tool to work on this main selection is the lasso tool, you can use any other PS tool for this, the quick mask is good too because of its simplicity, but the lasso tool allows you to have a very precise outline to start with, you can use the shift key to add to the selected area or the alt key to subtract from the selection for more precision, once you have a good selection save it as a new channel.
We have now a good selection of the area we want to process, so now we need to apply some feathering to the outline so that we have a diffused transition between the processed area and the non processed areas, the amount of feathering in pixels is something you will have to experiment a little if you are not familiar with this. The feathering needed will depend on the size of your picture in pixels and the resolution you are working with, as a guide I would say that a vertical image 500 pixels high at 72 resolution would need 3 pixels feathering, if the same picture was 2240 pixels high at 72 resolution you would probably need 8 to 10 pixels of feathering. What you are looking for is that the feathering applied does not interfere with adjacent areas of the selection.
Now make a new layer from the selection we just defined, we will be working on a new layer and not touch the original layer (background) at all, this is a good habit no matter what technique you are using, always create a new layer and leave the original untouched. If you are applying a process over the entire image do the same thing, duplicate the original layer to a new layer. In our case since we already have a selection, we will create a new layer with the content of our selection, to do this, go to Menu>Layer>New>Layer via copy or (Ctrl+J) this will create the new layer on top of the original.
It is time to apply a good dose of Gaussian blur on our new layer. The amount of Gaussian blur will also be determined by the size and resolution of your picture, so I'll use the same examples mentioned on Step#3 to explain how much Gaussian blur to apply; Example #1 image 500 pixels high at 72 would need Gaussian blur of 10 pixels more or less, Example #2 image 2240 pixels at 72 would need 20 to 25 pixels of Gaussian blur approximately. As you become familiar with this process you will find the best values for your particular style and needs, I give these numbers just as a starting point. Your first impression or thought when you apply the filter will be that it is too much blur to look good, but be patient and remember this is a subtractive method so we will be toning down gradually, avoid making judgements at this point.
Select the eraser from the toolbox and set the opacity to 50% and mode airbrush. What we are going to do now is subtract or erase blur of our selection, this has to be done in one pass, since we will have the opacity of the eraser at 50% this means that every time you pass over a specific area you will be reducing the blur by 50% the first time, if you pass a second time over the same area you will be subtracting again. If there is some area that you can't cover with the first pass don't worry, that is the nice thing about this method since you will be creating different densities and because of this, the final result will look more natural.
Choosing an adequate soft edged brush size to be sure that you make only one pass over the selection is a very important first step, so choose the brush size wisely, if you don't have the correct size on the palette you can create the size you need, or you can use the [ or ] keys to change the size of the brush. Using the selected brush, erase in one pass over the selection, be sure you can actually see all the selected area in your screen, change your navigator % accordingly.
Now select a soft edged brush, smaller in diameter than the size of the eyes, leave the opacity of the eraser tool at 50% and start erasing the blur over the eyes, lips, teeth, jewelry, and in some cases important features on the clothes, like lace, embroidery, buttons, etc. You can make as many passes over these areas as you need because you are subtracting, remember that the areas I just mentioned are the areas that need to be absolutely in focus, you don't really want any blur over those areas, except on very specific cases when you want to give the image a more ethereal look or for special effects. Some people leave blur over the eyebrows, but I think it doesn't help to the eye expression so I normally erase the blur over the eyebrows using a smaller brush. Note: for the very technical guys, don't think that because you set the opacity to 50% you will erase the blur in two passes assuming 50%+50%=100% this works in a different way, it is more like the first time you erase 50% but the next pass you are erasing 50% of 25%. Notice on the picture below right, how the image changes so dramatically just by erasing the blur from the eyes and lips, always keep this in mind, the viewer can be fooled just by giving some elements in focus against blurred elements.
Here comes the crucial step and this is when everything will make sense. Lower the opacity of the layer you have been working on to 50%, Once you do this everything should fall in place and you will see the real effect, you can fine tune lowering or increasing this opacity depending on your personal taste but the technique is designed for 50% ±10%. Now some of you may be asking, why did we change the layer opacity until the end, if this is the way we can visualize how the final picture will look? The reason is because if you lowered the opacity from the start the Gaussian blur you introduced originally wouldn't be very visible and you would have less control in the erasing process, by leaving the opacity at 100% while erasing and amplifying the navigator you can have better visual clues of what you are doing. As you become familiar with all the process then you can modify the layer opacity from the start if you prefer but it is not the best thing while you learn it.
Time to sharpen the image, before sharpening you will have to flatten the image, I normally save the file under a different name to be able to access the layers in the future, in case you change your mind about how much was too much. Your taste for blur will evolve greatly same as your photography skills with time, a lot of people go "whacko" at first with the selective blur, be careful. Sometimes it looks good on screen and it was too much for printing, and sometimes you think it is perfect and your client thinks you are nuts. To be on the safe side always save your processed file. There are many methods for sharpening, use whatever method you prefer, just be sure you sharpen after you apply this process first, never the opposite, it just works better that way. One method I find very practical is to flatten, then duplicate the background layer and apply the sharpening to the top layer, then you can play with the opacity slider to fine tune how much sharpening your image really needs, this is one more of those "situations" where the size/resolution/taste will determine how much is ok, photographers always differ on how much is good enough.
After sharpening, you can fine tune the sharpening by adjusting the opacity of the sharpened layer, in this case I decided to set the opacity to 80%.
Now we can see the result of the process, the left picture shows the original picture unprocessed, the picture to the right is processed and sharpened.
Click here for a larger version of the original picture
Click here for a larger version of the processed picture