Today’s Question: Can you provide some guidance for the Smart Sharpen settings in Photoshop when preparing an image for printing?
Tim’s Quick Answer: The first thing I recommend when using the Smart Sharpen filter is to set the Remove option to “Lens Blur”. The Reduce Noise setting will depend, of course, on the degree of noise in the image, but generally a low setting can be used because you will have presumably applied noise reduction to the image already. Then, for high detail images set the Radius to a value somewhere around 1.0 pixels (generally a little lower, except for very large prints). For images with lower levels of detail and smoother transitions of that detail, use a higher setting for Radius, generally around 2.0 to 3.0 pixels. Then set the Amount to a value of around 150% or so (ranging between around 100% and 200%) for high detail images, and around 75% for lower detail images. The specific settings will, of course, vary a bit based on the print size and the degree of detail in the image.
More Detail: When printing, the key thing to keep in mind is that you’ll generally need to over-sharpen the image. For glossy paper you don’t need to over-sharpen too much, but for matte papers (especially uncoated matte papers) you may have to apply sharpening that seems slightly extreme in order to produce a good result in the print.
It can take a bit of practice to get accustomed to what an image should look like on your computer display to ensure a print with optimal sharpening. Practice can be very helpful in this regard.
For high-detail images you want the sharpening effect to be applied to relatively small areas in relation to the size of the transitions among detail in the image. For lower-detail images you need to compensate by using a higher setting for Radius, so the sharpening effect will spread out a bit more.
When using a relatively low setting for Radius, you need to use a relatively high setting for Amount. And when you are using a relatively high setting for Radius you need to use a relatively low setting for Amount.
It is worth noting that you can also mitigate the sharpening effect in the dark shadow or bright highlight areas of a photo by expending the Shadows/Highlights section. This will provide independent controls for the Shadows and Highlights. You can then use the Fade Amount slider to reduce the application of sharpening in the shadows or highlights. You can also expand the range of tonal values being affected by this mitigation using the Tonal Width slider. Finally, you can use the Radius setting for Shadows and Highlights to determine how large an area around each pixel will be evaluated for purposes of determining whether that area represents a highlight or shadow area.