High Pass Sharpening

[Doug Nelson]

Sharpen with the High Pass filter for a non-destructive alternative to USM. [details]

[Leah]

Thanks, Doug -- that's a common technique very well explained.

[Gary Richardson]

I agree with Leah, very well explained. As an alternative to Overlay, try Soft Light and Hard Light blends for smoother/harsher sharpening actions. (My own preference is to use Soft Light.)

[JustChecking]

this technique just rulez, but one thing -

sorry if this question will be stoopid (i know it'll, so, sorry), but i kinda miss visual comparison - when i'm in the "high-pass" filter dialog, and switch off "preview", i see just the "oversaturated" version, which (at least for me) doesn't have give much reference w/ regards to sharpness of the original ; also (at least in my PS7) i can't switch of the layer while in filter dialog to compare the filtered result to original...

any ideas how this can be solved? only possibility so far i could think of was opening the pic in another window, or open it in irfanview and set the window to "always on top"...

[Doug Nelson]

You can click on the little icon at the bottom of the history palette that makes a new document from the current history state. That won't let you see them superimposed, but at least it's something. Once you've done a few you won't even need the preview option checked, the highpass preview will provide all the info you need.

[byRo]

Originally Posted by JustChecking

when i'm in the "high-pass" filter dialog...

When you are in the high-pass filter dialog, the only thing that you are adjusting is the radius. All the rest opacity / blending etc.. you will do after you run the filter.
The grey high-pass layer itself is showing what is going to be affected but it's pretty impossible to distinguish the light/dark greys. To get an idea of what is going to get sharpened, before running the high-pass filter I put in a threshold layer (at 130) above the target layer.
Now the dialog box may just show some greys but the image will be black and white - as you change the radius you see the effects.

Rô

[JustChecking]

thanks both of you, i guess i'll use both methods

the threshold idea is great... only thing i lack is the "power" of effect, but that can be kinda guessed from the spread and look of the pic...

thanks again!

[durob44]

This is the first tut i read here on this forum an i must admit as non-english speaking: i am impressed by the clarity.

[Paris]

Thanks, Doug, for an easy to follow, informative tutorial.

A question...

In step 3 you say " Here, her face looks appropriately sharpened, but her hat has been oversharpened."

Forgive the silly question, as this may be more to do with my eyesight than anything, but how do you tell?

I clicked the layers on/off and I can clearly see that sharpening effect, but how do I determine the hat has oversharpened. Is it a matter of choice or am I missing something very fundamental, that I should know, but don't?

Paris

[Doug Nelson]

It's purely a judgement call, based on personal taste (and perhaps some experience with a particular printer, but that's not the case here).

[Rob S.]

Very, very good. I hadn't known about this technique. I've always used the USM tool. I just tried this on a shot one of my clients had given me of two men working beside a truck. I compared the high pass technique to the file I had been working on that used the USM and was pleasantly surprised to see that the high pass looked measurably better.