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High Pass Sharpening

I was so impressed with the quality of sharpening that Chris Upton had used on his images in his exhibition (Masters of Vision, now finished) I decided I needed to re-evaluate my sharpening workflow.

I do not sharpen the psd file I create from my RAW file. I hold that psd file as an unsharpened master. You need to sharpen images to different extents depending on how it will be used. You would sharpen an image differently to be printed on canvas than you would if it was going to be printed on gloss paper. If you were then going to show it on a website it would need a different amount of sharpening also. So I hold my psd as a master and create jpegs from it, sharpen them according to use and then once the jpeg has been used I delete it – there is no need to keep it taking up disk space as I can recreate another from the master psd at any time.

Chris Upton reminded me about ‘High Pass Sharpening’. I had used this in the past but had somehow drifted back to the usual Unsharp Mask (USM) sharpening that most people use. The difficulty with USM is it increases any noise in the image as it works on adding contrast to edges in the image.

High Pass sharpening has the advantage that it is performed on a separate layer so it can be masked out of some areas and it can be strengthened or reduced in effect by using the opacity slider. If you don’t like it, it can be deleted and you can turn the layer on and off to check the effect.

So how do you do it. It is very easy

1. Duplicate your image (press ctrl-J)

2. Select Filter>>Other>>High Pass

3. Set the radius to 10

4. Click OK

5. Change the blending mode of the layer to Hard Light

6. Zoom in to 100% to be able to judge the next step

7. Experiment with setting the opacity slider on the layer anywhere from about 20% to 70% to get the amount of sharpening you are after.

8. If some areas do not need sharpening or need to be softer then use a mask and set the opacity of the brush to remove the level of sharpening to the extent you want.

This sharpening process could improve your images a great deal.

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