Often it’s necessary to add a degree of electronic sharpening to your pictures, and the Unsharp Mask filter in Photoshop offers the ideal solution. This tool allows you to alter the amount and location of sharpening applied to suit the image you’re working on. Below we’ll offer our top suggestions for how to use unsharp mask subtly and effectively.
But before we get to our tips, we thought we would take a quick look at how to use Unsharp Mask at a glance.
Photoshop’s Unsharp Mask filter provides you with three sliders, each of which affects sharpness. Below we’ve explained each of the three sliders and typical settings you might use with them.
This is like a volume adjustment – the higher the percentage, the stronger the sharpening effect. Whether you use a low or high percentage will depend on the position of the other two sliders.
Typical setting: 50-200%
Good starting point: 100%
Sharpening works on the edges of a subject by increasing the contrast at these points, making these outlines stand out more prominently. The higher the Radius amount, the stronger the sharpening effect. It’s measured in pixels, as this is the width of the sharpening effect.
Typical setting: 1-8 pixels
Good starting point: 1 pixel
Confusingly, with this slider, the higher the amount set, the lower the sharpening effect. This control defines what counts as an edge for the sharpening applied by the other two sliders. At ‘0 levels’ every pixel in the picture counts as an edge, so is sharpened. At high values (25 levels and above, for example) only high-contrast edges are sharpened.
Typical setting: 1-15 levels
Good starting point: 5 levels
Even apparently clear, high-contrast shots need digital sharpening
View at 100% and check the edges as you drag the sliders
9 tips for how to use Unsharp Mask
Sharpening should be your final editing task. Only attempt it after all other corrections.
The USM filter’s sliders work in unison, so the effect of one can be cancelled out by another.
The USM filter offers two types of sharpening. One works overall, the other strengthens edges.
With a landscape, lots of detail will need a little sharpening. Keep Radius and Threshold low.
For simpler compositions, just sharpen the edges. Use a higher Radius and high Threshold to make sure any even areas of tone don’t look grainy.
The amount of Radius needed will vary depending on the number of pixels in the picture.
You’ll need to do more sharpening for shots that are going to be printed.
How much sharpening you do is a matter of taste – it can also reveal things you may want to hide!
Bright or dark outlines around subject edges are a sign of over-sharpening. Also look out for grain and noise in areas you didn’t want to be sharpened.