How to sharpen in Photoshop
Sharpening your photos is one of the least exciting things you can do in Photoshop but also one of the most important things too. It’s also right at the top of the frequently asked questions I get whilst teaching photo post processing.
Let’s start by clearing up a few misconceptions. You don’t need to sharpen every photo and you don’t need to sharpen a whole photo the same amount. For example if you’ve taken a dreamy soft portrait you may want to sharpen just the eyes or you may want to sharpen nothing at all… It’s ultimately your choice.
When to sharpen
In this post I’m only looking at sharpening in Photoshop and I’m assuming you’re starting with a photo that’s basically in focus where it should be. Many people will make the fundamental mistake of sharpening just after they’ve applied their Photoshop effect, whatever that may be. WRONG!
For me sharpening is the very last thing you do moments before the image leaves your computer and goes to your printer, blog, Facebook page etc. In other words don’t sharpen your image and then resize it, always resize it first and then sharpen.
Unsharp Mask vs Smart Sharpen
For years I’ve used Unsharp Mask as my “go to” sharpen tool but no more. Photoshop has a raft of sharpening options but the Smart Sharpen filter has a couple of features that make it the best sharpening filter in Photoshop.
The Smart Sharpen Filter has three type options. “Gaussian Blur”" is in effect the same sharpening as Unsharp Mask. “Lens Blur” is my usual setting and “Motion Blur” try’s (and usually fails) to reduce blur from moving subjects.
To get the best from Smart Sharpen set the amount to 500% and the radius to around 20 and you’ll notice a bunch of halos around edges in the photo. Slowly reduce the radius until the halos are all but gone. That’s the radius set for that image. Finally, reduce the amount slider to get the sharpen effect you desire.
Obviously there’s no magic number that works for all images so be prepared to experiment a little.
Good as Smart Sharpening is you do have to remember that it’s a global effect which effects all the pixels in the image and whilst that’s usually exactly what you want there are times when it’s not. For example perhaps you have a shallow depth of field image, you don’t always want to sharpen the out of focus areas.
One way to do this is to make a duplicate layer of the image, sharpen the duplicate layer and use a layer mask to limit the sharpened layer to just the bits you wanted to sharpen.
However for users of Photoshop CS5 and CS6 the best way to do this is with the Sharpen Brush which had a radical overhaul in CS5 onwards and is the best sharpening tool in any part of Photoshop as long as “Protect Detail” is turned on in the tool option bar. It’s as simple to use as any brush in Photoshop, all you do is paint where you want to sharpen and the more you paint the sharper thing become. Gone to far? CTRL+Z will undo the last click and CTRL+ALT+Z will keep going back one histrory step at at time.
- Only sharpen AFTER you resize your photo
- Use Smart Sharpen for Global Sharpening
- Paint with The Sharpen Brush for local sharpening