For many years the Unsharp Mask tool has been the mainstay of sharpening in Photoshop, and while it is not as sophisticated a tool as Smart Sharpen it is still useful and especially as a global sharpening tool.
1. From the internet, search and make a copy of the Lavender Flower. Lets say his image is has no critical highlight or shadow areas to worry about blowing out or plugging in, so this is image is a good candidate for using the Unsharp Mask tool without fear.
2. Set the view of this image to 100% (Cmd+Option+0/Ctrl+Alt+0). Even if you zoom in to view edges and details while trying various sharpening values, always view your image at 100% when making final sharpening judgments because other percentage views will not provide an accurate view of the impact of the sharpening.
3. Duplicate the background layer and name it USM. As always, I suggest keeping and placing the original image on screen in the upper left corner to use as an unaltered reference image. I still like to create a sharpening layer(s) so I can try options and easily turn their views off and on.
4. Position the image within its window so you can see an entire petal, some of the yellow stamens, and some background as well so you can monitor the impact of the sharpening on all the various image elements.
5. Choose Filter ➢Sharpening ➢Unsharp Mask to activate its dialog.
6. You will want now decide how much Amount Radius and Threshold to apply to this image. Astandard starting place for good quality image would be Amount 100%, Radius 1, and Threshold 0.
- The Amount will control (in %) how much increase in contrast will occur between lighter and darker pixels. Higher values will create greater sharpening effects. Values range from 75% for low quality web images to 300% for high quality print images.
- The Radius controls the width (in pixels) of what will be evaluated and adjusted during sharpening. Higher values create thicker sharpened edges. Values are usually resolution dependent and range from 0.5 for low resolution web images to 2.0–2.5 for high resolution print images. Starting values can be determined by this formula: image resolution divided by sharpening amount, such as 300ppi ÷ 200 = 1.5.
- Threshold specifies (in grayscale values) the difference in grayscale value that must exist between two pixels before sharpening (contrast increase) will be applied to those pixels. You can use this Threshold value to protect smoother/lower contrast areas of your image from sharpening. Higher values equate to more protected areas. I may use Threshold to prevent smooth image areas, like skin tone areas, from acquiring graininess during sharpening, and particularly when I apply large Amount and Radius values. Values range from 1 to 5 depending upon how much of the image you want to protect from sharpening. Note: This is typically not an effective tool for preventing highlight blowing out and shadow plugging because this is not a tonal range–based sharpening control. This is a high quality image with lots of image data, so if you choose to you can apply a significant amount of sharpening without the image showing any ill effects such as halos or pattern creation. Besides the standard starting values mentioned above, there is not one “right” answer to these three values. Here I apply an Amount = 200, Radius = 2, and Threshold = 0. I chose a larger than standard amount because I wanted the details of the leaves to really pop out. With images like this you can go as high as 300%. Amount values above 300% often create halos and graininess especially if you apply no Threshold. If I wanted to protect the smoothness of the interior of the petals and/or I saw some graininess developing in the out of focus background, I might apply a Threshold value of about 1–3 to accomplish this; I chose not to here.
7. Now rename this sharpened layer “USM 200_2_0” to indicate the type and values for the sharpening you applied. Create several different labeled sharpened layers with various values and compare your results to see the impact of changing the three variables. And don’t be afraid to zoom in to watch the results at the pixel level (I learn all sorts of stuff doing that!), but always return to the 100% view to make your final evaluation. Note: I tend to oversharpen a bit for print, as some of the sharpening inevitably is lost during the RIPping and screen process, and undersharpen a bit for the Web, because compression tends to raise Cain with high contrast sharpened edges.
8. When you finish with your image, make a copy of the image, activate the layer you like best (turn off the rest) and flatten the image to remove its layers. This type of image—with lots of data but no critical highlights and shadows that may or may not have low contrast areas you want to protect—will respond well and produce good sharpening results from the use of the Unsharp Mask tool. For images like these Unsharp Mask is an easy and fast dialog box to control to produce good results. In the next exercise we will look at an image that is made better by using Smart Sharpen.
1. From the internet, search and make a copy of the Lavender Flower. Lets say his image is has no critical highlight or shadow areas to worry about blowing out or plugging in, so this is image is a good candidate for using the Unsharp Mask tool without fear.
2. Set the view of this image to 100% (Cmd+Option+0/Ctrl+Alt+0). Even if you zoom in to view edges and details while trying various sharpening values, always view your image at 100% when making final sharpening judgments because other percentage views will not provide an accurate view of the impact of the sharpening.
3. Duplicate the background layer and name it USM. As always, I suggest keeping and placing the original image on screen in the upper left corner to use as an unaltered reference image. I still like to create a sharpening layer(s) so I can try options and easily turn their views off and on.
4. Position the image within its window so you can see an entire petal, some of the yellow stamens, and some background as well so you can monitor the impact of the sharpening on all the various image elements.
5. Choose Filter ➢Sharpening ➢Unsharp Mask to activate its dialog.
6. You will want now decide how much Amount Radius and Threshold to apply to this image. Astandard starting place for good quality image would be Amount 100%, Radius 1, and Threshold 0.
- The Amount will control (in %) how much increase in contrast will occur between lighter and darker pixels. Higher values will create greater sharpening effects. Values range from 75% for low quality web images to 300% for high quality print images.
- The Radius controls the width (in pixels) of what will be evaluated and adjusted during sharpening. Higher values create thicker sharpened edges. Values are usually resolution dependent and range from 0.5 for low resolution web images to 2.0–2.5 for high resolution print images. Starting values can be determined by this formula: image resolution divided by sharpening amount, such as 300ppi ÷ 200 = 1.5.
- Threshold specifies (in grayscale values) the difference in grayscale value that must exist between two pixels before sharpening (contrast increase) will be applied to those pixels. You can use this Threshold value to protect smoother/lower contrast areas of your image from sharpening. Higher values equate to more protected areas. I may use Threshold to prevent smooth image areas, like skin tone areas, from acquiring graininess during sharpening, and particularly when I apply large Amount and Radius values. Values range from 1 to 5 depending upon how much of the image you want to protect from sharpening. Note: This is typically not an effective tool for preventing highlight blowing out and shadow plugging because this is not a tonal range–based sharpening control. This is a high quality image with lots of image data, so if you choose to you can apply a significant amount of sharpening without the image showing any ill effects such as halos or pattern creation. Besides the standard starting values mentioned above, there is not one “right” answer to these three values. Here I apply an Amount = 200, Radius = 2, and Threshold = 0. I chose a larger than standard amount because I wanted the details of the leaves to really pop out. With images like this you can go as high as 300%. Amount values above 300% often create halos and graininess especially if you apply no Threshold. If I wanted to protect the smoothness of the interior of the petals and/or I saw some graininess developing in the out of focus background, I might apply a Threshold value of about 1–3 to accomplish this; I chose not to here.
7. Now rename this sharpened layer “USM 200_2_0” to indicate the type and values for the sharpening you applied. Create several different labeled sharpened layers with various values and compare your results to see the impact of changing the three variables. And don’t be afraid to zoom in to watch the results at the pixel level (I learn all sorts of stuff doing that!), but always return to the 100% view to make your final evaluation. Note: I tend to oversharpen a bit for print, as some of the sharpening inevitably is lost during the RIPping and screen process, and undersharpen a bit for the Web, because compression tends to raise Cain with high contrast sharpened edges.
8. When you finish with your image, make a copy of the image, activate the layer you like best (turn off the rest) and flatten the image to remove its layers. This type of image—with lots of data but no critical highlights and shadows that may or may not have low contrast areas you want to protect—will respond well and produce good sharpening results from the use of the Unsharp Mask tool. For images like these Unsharp Mask is an easy and fast dialog box to control to produce good results. In the next exercise we will look at an image that is made better by using Smart Sharpen.
Unsharp Mask
![Unsharp Mask]()
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