Freelance Photographer
Seeing things differently
A taker of Photographs - A creator of images

Sharpening an Image...

When you sharpen an image using unsharp mask in Photoshop or any other digital imaging software for that matter the software lightens a pixel on one side and darkens a pixel on the other side of the selected pixel... This process increases the pixels contrast therefore giving it a sharper appearance, as you can’t actually sharpen a blurred image... A straight forward UnSharp Mask (USM) may be OK for the majority of images, but there are occasions when this gives an unnatural look, so I will describe a few other ways to give a sharpened appearance on a image...

Let’s take a crop of a steam train showing when and where it was built as our example of how to sharpen an image...

• Brightness & Contrast
• High Pass
• Lab Colour
• Layered Unsharp Mask

Brightness and Contrast method...

• A quick adjustment to improve the impression of shrpness can be achieved by using a Brightness and Contrast adjustment layer...

• Just click on the New Adjustment Layer icon in your tools palette
which will bring up a window like the one on the right...

• You merely use the sliders to adjust the image until it looks sharper...

The effect of the Brightness and contrast can be seen in the image below right...

Unsharp Version

High Pass method...

Creating a new layer and applying the High Pass filter can also give an appearance of sharpening to an image...

• Duplicate the original layer by opening the layers folder (F7) and dragging the background layer to the icon highlighted in green, as shown above right...

• From the menu bar choose... Filter... Other... High Pass as shown on the right...
Just use the Radius slider to adjust the amount of sharpness...



• You then change the blending mode of this layer to Overlay as shown bottom right...

The results of this method can be seen in the image below right...

Unsharp Version

Lab Colour method...

This method applies a subtle sharpness to an image...


• From the menu bar choose... Image... Mode... Lab Color as shown in the image on the right...

• If your channels tab is not showing... Click on windows from your menu bar... Click on Channels...

• From your Channels Palette choose the lightness channel...

• You then simply apply Unsharp Mask to this channel...

• You need to convert the image back to RGB Color by clicking on Image from the menu bar and chosing... Mode... RGB Color...


The results of this method can be seen Below right...

Layered Unsharp Mask method...

This is the method I primarily use, it´s extremely simple and gives you better control than just using the plain unsharp mask, which automatically sets the opacity of both light and dark pixels equally...

• Duplicate the original layer by opening the layers folder (F7) and dragging the background layer to the icon highlighted in green , or holding down the Ctrl key and pressing the J key...
• From the Menu bar click on Filter... Select Sharpen... Click on Unsharp Mask... Select an amount to suit the image and click OK......
• Now duplicate the background copy that you have just applied the Unsharp Mask to... You should now have three layers in your layers pallet... The original background layer, background copy and background copy 2...
• Select the background copy layer in the layers pallet... Go to the top and click on the blending mode option as shown in the image right and select Darken as the blending option...
• Select the background copy 2 layer in the layers pallet... Go to the top and click on the blending mode option as shown in the image right and select Lighten as the blending option...
• Now this is the clever part.... You can adjust the opacity of the individual copy layers to determine exactly how much lightness and/or darkness you wish to apply to the sharpening... The opacity box is just to the right of the blending mode option box, and can be seen in the image at 100%...
I set the opacity to 100% on the background copy layer that had the mode set to darken... I set the opacity to 61% on the background copy 2 layer that had the mode set to lighten...

The finished image should look like the sharpened one, bottom right (Sharpened version)... If I had just used unsharp mask the highlights would have become extreme because of the white paint... Subjects with a lot of light colours will benefit from more darken in the sharpening and subjects that are dark will benefit from more lightening in the sharpening...

It's common sense really to have two layers, one to control how much darkness is applied and one to control how much lightness is applied...

Unsharpened version