We all want our images to look the best. For most of us, it is our job to make everything, including our images, look good. Good color, contrast, and balance are important, but none of that matters if your image is blurry or out of focus. For some photos it can make the image that much more powerful to sharpen the image. For example, if you have a geological image, and it looks good, you can make it look great and more defined by sharpening it.
There are different methods to sharpening, each one will give you better results, depending on the image. Some are simple settings, and some are meant for specific purposes. If you go to Filter> Sharpen> you will find a set of sharpening filters that can help your images to look much more crisp, and can even solve common problems, such as motion blur.
The image below is of a sea turtle in a holding tank. The image is slightly blurry, and lacks detail. The edges are not defined well, lowering the quality of the image. The turtle and his skin have a lot of interesting texture, but the details are blurry.
Start off by duplicating your background image. This way, if you make a mistake, you always have a spare image to go back to. For this image, I chose Filter> Sharpen> Unsharp Mask. Unsharp mask basically uses an optical trick, overlaying a blurred copy of the image, but masked, to increase contrast between edges, giving the illusion that your image is sharper than before.
A dialog box will open that gives you 3 options: Amount, Radius, and Threshold. Each one of these settings has an affect on the other one. The amount is the amount, or strength of how much contrast you want in the sharpened edges. I chose 108, but depending on your image, your values could be anything. Radius is the amount of blur that you want to apply to your image copy, which I set to 12.
Threshold tells Photoshop how much pixel information is the minimum before the unsharp mask is applied. This keeps from sharpening fine details and increasing noise, but still sharpens the larger items in the image. I set this to 45 for my image, but depending on what you are sharpening, and the resolution of your image, your settings may or may not be close to mine. The result is shown below:
The next image is very blurry, and really has no focal point in the whole scene. With a simple trick inside Photoshop, we can add instant contrast, that we can make changes to over and over again. The High Pass filter is a common way to sharpen images, but it isn’t as straightforward as selecting the Sharpen filter menu.
Duplicate your original layer, like you did before. Simply go to Filter> Other> High Pass. A dialog box will come up, and all you do is select the radius. You will get an unwanted graying effect, but that is okay, because we can fix that easily. Go to your Layers panel, click the drop down menu for blend mode and choose Hard Light. This will get rid of the gray effect, while adding edge contrast to your image, giving it a sharper look.
Here is the result. You will notice that the branches up front are much sharper and more defined than before. This adds dimension to the image, without adding too much noise in the rest of the image. You can also see that the ridgeline is more defined, without the main bulk of the image, the forest, becoming grainy.
Smart Sharpening is another feature that can fix unique problems that you will encounter when images aren’t as sharp as they should be. In the example below, we have a coiled chain with a hook on each end. The image is good, but if we want to increase contrast and really sharpen the image, smart sharpen can do that. It also has a couple of unique settings that you won’t find anywhere else.
Go to Filter> Sharpen> Smart Sharpen. When the dialog box appears, you will notice that this interface has more settings than others. This feature is really interesting, because you have the normal settings of Amount and Radius, but Threshold is missing. In its place is the Remove setting, where you can choose between Gaussian Blur, Lens Blur and Motion Blur. Each one is intended to correct a different problem.
Gaussian Blur and Lens Blur are close in their results, but Gaussian blur is intended to sharpen the image with a small amount of blur or fuzziness. Lens blur is supposed to be used to correct a lens blur that can sometimes occur with a camera malfunction or when the photographer has taken the picture slightly out of focus.
Motion blur is supposed to help remove the blur that happens when the photographer or subject is moving while the picture was taken. When you choose motion blur, you are able to adjust the angle, so that the motion blur can be corrected, depending on the angle of the motion. This provides a lot of flexibility when correcting motion blur, because images aren’t always taken at a straight angle.
If you click the button from basic to advanced, the Smart Sharpen dialog box adds 2 more tabs at the top. One is to sharpen shadows, and the other one is for sharpening highlights. This gives you control over sharpening specific aspects of your images, without sharpening others. The settings are just like the standard sharpen filter, with Amount, Radius and Threshold settings for each one.
It is important to know what tools are available to sharpen your images. Choosing the right filter can really make your images look great, or they can save an image that is blurry or just isn’t sharp enough.