High pass filter: my newest favorite tool

[Justan]

I bought a book recently and in the book they made an illustration of using Photoshop’s High Pass filter. I didn’t quite get what the book was describing, so I started poking around on the web to find other examples. Low and behold, the 3rd reference Mr. Google brought me originated from this very site, and the article linked here:  http://www.luminous-landscape.com/tutorial...harpening.shtml

Like any tool it can be over done, but it can make for a very nice, even remarkable improvement in the end results.

Enjoy and thanks to the management for the excellent tutorial!

[sniper]

I bought a book recently and in the book they made an illustration of using Photoshop’s High Pass filter. I didn’t quite get what the book was describing, so I started poking around on the web to find other examples. Low and behold, the 3rd reference Mr. Google brought me originated from this very site, and the article linked here:  http://www.luminous-landscape.com/tutorial...harpening.shtml

Like any tool it can be over done, but it can make for a very nice, even remarkable improvement in the end results.

Enjoy and thanks to the management for the excellent tutorial!

This methods been around for some time, it's often mentioned as high pass sharpening in publications, but not often discribed in detail.

[stamper]

Some people recommend setting the radius at 10. It works but what I find "best" is 3 and duplicating the layer. Try it?

[kers]

Some people recommend setting the radius at 10. It works but what I find "best" is 3 and duplicating the layer. Try it?

hello Stamper- Your method does not seem to work well with grainy pictures..?  ( gets more grainy)

or am i doing something wrong?

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PS i did somthing wrong-  intens light   vs hard light

PK

[bill t.]

Also on the "Blending Options" panel the "Blend if Gray" sliders act something like the highlight and shadow controls in Smart Sharpen.  I sometimes use the high pass trick not so much for sharpening as to brighten up textured areas, reducing the white "This Layer" slider controls the amount of brightening and sharpness.

[stamper]

[quote name='kers' date='Oct 21 2009, 12:58 PM' post='318992']
hello Stamper- Your method does not seem to work well with grainy pictures..?  ( gets more grainy)

or am i doing something wrong?

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You seem to have answered your own question? Not all methods work with all images. It is all a matter of judgement? The high pass method is very flexible but one of the easiest to apply? Duplicating does give an "extra bite" which can work on some images. When I do it I sometimes think it is too strong and delete the duplicated layer. I also apply it via a mask to some parts of the image thus avoiding smooth areas. High pass is essentially an edge action which tries to avoid smooth areas. If you look at my Flickr gallery and look at the Waverley image you will see that the water is sharp and the rest of the image is smoother. This was achieved with the duplication method and  IMO has sharpened the water nicely but the rest of the image is softer? A matter of opinion?

[stamper]

Also on the "Blending Options" panel the "Blend if Gray" sliders act something like the highlight and shadow controls in Smart Sharpen.  I sometimes use the high pass trick not so much for sharpening as to brighten up textured areas, reducing the white "This Layer" slider controls the amount of brightening and sharpness.

Blending Options - Blend if

A little understood tool that is worth learning and should be in every ones armoury?

[Brad Proctor]

I've experimented quit a bit with the High Pass filter and Rather than setting the radius to 10 and lowering the opacity, I prefer to set the radius to between .5 and 2 with 100% opacity, a little lower if necessary.

Also, I often use multiple layers at it seems like the lower the radius the more fine details are sharpened.  So I might add a layer with .5 radius, another at 1, and another and 2 with 75% opacity.  All depends on the image.

Size of the image is important too.  When sharpening an image for the web I often use a radius like .3