Gelbach Designs Inc.

Let there be no confusion: All digital pictures, and many renderings or designs, benefit from sharpening as part of the work flow. The few exceptions are when low contrast or softness is desired for an artistic effect.

There are many ways to sharpen an image in Adobe Photoshop. Most Photoshop users use the simple sharpen commands in the Filters–>Sharpen menu, such as Smart Sharpen or Unsharp Mask. However, most professionals tend to use less intuitive processes ending with better results. This is a description of one of the simpler methods, High Pass Sharpening.

For this quick tutorial, I have chosen an old scan from a developed disposable camera. This is an image of some work we did years ago that will provide a great example for the potential client that just called about turning his pool and carriage house into a pirate scene (you would do it too, if you had the cash, don’t lie). This small rough looking image is the only proof that remains of our participation in this attraction.

So, that’s what we have to work with. It’s not great, and we will be applying more techniques to clean it up. However, the focus of this tutorial is sharpening in Photoshop, so clearly we should just stick to defining those steps.

Step 1 • Open Image, Duplicate Layer

After you have opened the image in Photoshop, in the layers window, right click on the background layer and select duplicate. You should now see two layers. Most likely labeled ‘background’ and ‘background copy’. The latter being the topmost layer.

Step 2 • High Pass Filter

Now we will use the Highpass filter on the duplicated layer. On the menu at the top of Photoshop’s window, click on ‘Filter’, then click on ‘Other’ at the bottom of the list, and finally click ‘Highpass’. Selecting what value to use for the High Pass radius is a matter of taste and what blending mode you plan to use later. This is a value that you will be more accustomed to as you utilize this sharpening technique.

Some of the best results I’ve seen were attained by using a very small value in high pass, so that you can just see the lines in the high contrast areas. However, this really depends on which blending mode you are planning on using. Small values are great for using linear light, but a larger high pass radius value would be better if you plan to use the blending mode soft light. Let’s talk about the blending modes now.

Step 3 • Blending Mode

The blending modes in Photoshop are fantastically powerful. I’ve seen so many examples of amateur designers trying to (for example) make a Photoshop brush look like existing graffiti on a picture of a brick wall. If only they knew how to change blending modes, it would look real and be done in a small fraction of the time. If you are unfamiliar with them, I highly recommend playing with them after you are done with this tutorial.

What we are using the blending modes for, in this image, is to combine our highpassed grey-looking layer with the original layer. In short, the parts of our high passed layer that are medium grey will not affect the image. the parts that are slightly lighter will lighten, and (you guessed it!) the parts that are slightly darker will darken.

The blending modes can be found at the drop down list in the top of the layers window.

Near the middle of the drop down list are the blending modes soft light, overlay, and linear light. These are the ones most commonly used for high pass sharpening. For this example, lets use linear light, which is the strongest (too strong, if your highpass radius was large) of the blending modes. If you find it over sharpens your image, try something more subtle, like soft light.

Step 4 • Compare

Now it’s time to see what you have accomplished. In the layers window, beside the ‘Background copy’ layer, is an eye icon. Position your mouse pointer over that icon and click it on and off as you look at your image. You will see that the image that you thought was just fine before, is now better and sharper. Is it too sharp? If so, try using soft light as the blending mode. Worst case, you can just delete the layer and start over now that you have a better grasp on what you are doing.

Step 5 • You’re done

I have included a before and after image along side each other so that you can see the results for this particular image. Check out the definition in the brick. Now you can see how blurry the original image looks in comparison.

Now you can save your image and go on about your business. If you learned something from this tutorial, don’t be afraid to share the link with others. Your friends might be able to learn something from this as well. You can copy this link: http://gelbachdesigns.com/2010/06/sharpening-in-photoshop/

Thanks for reading, I hope it helped

Tags: blending modes, images, photos, photoshop tutorial, sharpen in photoshop, sharpening