Technical - Digital - Sharpening

1 Every digital image needs sharpening. If this is not done by the digital camera or the film scanner, you must do it in your chosen software, e.g. Photoshop. Never use Filter - Sharpen - Sharpen, Sharpen Edges or Sharpen More.

2 Simple sharpening

2.1 Use Filter - Sharpen - Unsharp Mask.

2.2 Start with: Threshold = 0, Radius = 1.0, and with Preview ticked

2.3 Watch your image as you move the Amount slider. The larger your image file and; resolution, the higher the figure required. Never over-sharpen, it looks awful.

3 A much better method is to use High Pass.

3.1 Here is an image to start work on:

Right-click the picture and choose Save As if you want to save this image to your own folder and try the exercise yourself in Photoshop.

3.2 In your Layers Palette, drag the Background on to the New Layer icon:

to get a Background Copy layer:

3.3 With Background copy still highlighted, use Filter - Other - High Pass: Start with a radius of 5.0 pixels, and click OK.

3.4 Now, in your Layers Palette, choose a Blend Mode of Hard Light:

3.5 The image is sharpened, and the shadows lightened: If the effect is a little overdone, go back to the Layers Palette and change the Blending Mode to Soft Light.

3.6 You can also alter the degree of sharpening by changing the radius no. in the High Pass filter - lower for a softer effect, higher for more edge-sharpening.

3.7 When you're happy with the result, use Layer - Flatten Image to finalise it.

3.8 If you're using one of your own images, and it has more than one layer, you must either flatten all the layers before you do the copy, or you must do a Merge Visible to a new layer, before you start.Merge Visible to a new layer is another tip on this page.