High pass an Old Man

The high pass filter is often overlooked as a method of sharpening in Photoshop perhaps because it is not grouped with the other sharpen filters hidden away as it is in the “other”  section of the filter menu.  Of course sharpening really is increasing the contrast of neighbouring light and dark pixels. The typical implementation of the filter is to duplicate the background layer apply a low pixel radius high pass filter and change the blending mode of the layer to overlay and adjust the opacity of the layer to taste.  The soft light blending mode has a less harsh sharpening effect and hard light and linear light have harsher effects.  I find the filter useful for sharpening images that have well defined edges already such as architectural images and less so for portraits as it can be quite unflattering, incidentally an inverted high pass filter is useful for portraits for a quick smoothing of skin (used with layer mask and low opacity layer).  In the example here I used the filter to exaggerate the lines on the old mans face, I duplicated the high pass layer a few times and also used a number of other blending mode techniques to desaturate and tone the image.  As with all blending modes a little experimentation can yield pleasing results……

Before

 

After

Cheers Colin