As mentioned in a previous article, Unsharp Mask is your starting point in learning how to sharpen in Photoshop, but it’s fairly limited. We’ll be looking at Smart Sharpen next, and tailored towards Adobe’s latest Photoshop CC. Older versions of Photoshop are slightly different but the overall function of the filter is the same.
Just as it sounds, Smart Sharpen is a much smarter way to sharpen, when compared to Unsharp Mask. As with Unsharp Mask, this should be one of the final steps in your workflow and completed only after your image is resized to its final output size and resolution (be it for print, web, or digital display). You should also be making these corrections to a duplicate layer only so that it does not permanently alter your image.
The biggest improvement of Smart Sharpen over Unsharp Mask is the ability to control the amount of sharpening in the highlights and shadows. Let’s take a look at the controls.
Amount. This slider controls the amount of contrast added to the edges, as in Unsharp Mask.
Radius. Similar to Unsharp Mask, this control sets the radius that the filter is applied around the edges. The larger the radius, the further away from the edges contrast is added, and the more pronounced the sharpening will be.
Reduce Noise. An addition to Photoshop CC over older versions. This control will reduce noise while preserving sharpening around the edges. Remember the Threshold control in Unsharp Mask? Where a threshold of zero would actually sharpen noise? This new control finds that noise and reduces it.
Remove. This control sets the algorithm that is used to sharpen around the edges, and there are three options.
- Gaussian Blur – this is the same method used in Unsharp Mask. It is much more broad and indiscriminate.
- Lens Blur – this is a much more precise way of sharpening detail in an image. It detects the edges in a much finer manner and reduces the halos that otherwise appear using Gaussian Blur, as you may have noticed in Unsharp Mask.
- Motion Blur – I’ve had limited success with this function. Motion Blur attempts to correct any motion that may have occurred during capture. You need to set the direction that the camera was moving for it to be effective. But as proud photographers we should always live by the mantra “get it right during capture”.
Advanced Controls – this is where Smart Sharpen really takes a departure from Unsharp Mask. The Shadows and Highlights tabs allow you to control the amount of sharpening done in these tonal areas. Think of these controls as setting how much the sharpening is reduced in these areas, not how much is applied.
- Fade Amount – sets how much to mask in the shadows and highlights. A high value will reduce, or “fade”, sharpening in the shadows or highlights. A low value will not reduce any sharpening in the shadows or highlights.
- Tonal Width – this controls the range of tones in the highlights or shadows that are masked from sharpening. A low value, say 10%, is telling Photoshop to only reduce sharpening in the brightest ten percent of highlights or the darkest ten percent of shadows. A higher number will reduce the sharpening in a wider tonal width of shadows or highlights, resulting in a more gradual transition.
- Radius – the radius value is set to determine how many pixels are compared to determine if areas fall within the specified shadows or highlights.
The order in which I Smart Sharpen is to start with the general sharpening settings. As with Unsharp Mask, I start with the Amount, set the Radius, and then with Smart Sharpen adjust the Noise setting. I keep this low to avoid an image that’s too soft.
I then move down to the Shadows next. This requires a lot of practice, changing sliders, turning preview off/on, and interpreting your image. Where are the eyes supposed to be drawn? To the shadows? If so, you’ll probably want to reduce the masking taking place in the shadows, so your Fade & Tonal Width settings should be low. Don’t care about the shadows? Then set those adjustments higher so that sharpening is reduced in those areas – this will also limit the amount of grainy noise introduced into these areas. The same concept applies with your highlights.
There is no one cookie-cutter approach to using Smart Sharpen. Have an understanding of what the controls do, and then adjust the settings until you get an image that works for you!