Understanding the basics of Sharpening in Photoshop

Sharpening is one of those everyday tasks that most photos can benefit from. In this post I’ll explain what sharpening is, when you should perform it and how to do it. The information here, although it is explained using Photoshop, is relevant to all photo editing programs.

Sharpening does as its name suggests and sharpens the image making it look crisper and making the edges in the image more distinct.

In the darkroom the process is achieved by taking one negative and a slightly blurred positive image, sandwiching these together and making a very quick exposure of this sandwich. Then the exposure is completed using the negative. The resulting image has sharper and crisper edges than it would have had if the blurry (unsharp) mask image had not been used. The typical sharpening tool used in Photoshop and other graphics programs is named after this traditional darkroom process and is called the Unsharp mask.

In a graphics editor the Unsharp mask works by creating small halos along the edges in the photo. These halos enhance the contrast between the edges and the surrounding pixels making the edges look more obvious and giving the image a crisper and sharper look.

Written by Helen Bradley – Pro Photoshop and Photography: Understanding the basics of Sharpening in Photoshop.