sharpening methods - which one when?

[hankalive]

What is the difference between using 'unsharp mask' and 'sharpen' or 'sharpen edges' or 'sharpen more' in the filter options of PE? Also, why would you use these instead of adding a hard light layer and high pass filter as lesson 19 of the layers class teaches?

I have read over the 'helps' definitions of each one, but I do not understand where each would be best applied.

Thanks!

[kayser]

Hi!

I've always leaned towards unsharp, and I just checked Scott Kelby's book, and he says, "Unsharp mask is the undisputed first choice because it offers the most control over the sharpening process." And Barbara Brundage (author of Missing Manual) says that it's the most versatile and most capable of the sharpening tools.

When I first started using Elements, I couldn't figure out why anyone would use unsharp, but it's named after a darkroom technique, in case you didn't know.

I'm sure Butch or someone will be along to give you more details. And I've put something in your other thread, so there aren't duplicates threads going on the same subject.

[Grant]

Unsharp mask is the grand daddy of sharpening. It gets its name from an old photographic trick. it really doesn't sharpen but increases the contrast between boundaries that are set with the three sliding scales. This tool gives the most latitude but requires a bit of studding to get it correct.

Sharpen is the same as if you use Unsharp mask and select Amount 50, Radius 1, and Threshold 0

Sharpen More is the same as if you use Unsharp mask and select Amount 100, Radius 1, and Threshold 0

Sharpen edge is a rather complex form of sharpening that uses a set of algorithms to just sharpen specific boundaries and not the whole image.

Grant

[Daviskw]

Hi there

Complicated stuff huh.. bet like me you could care less that using unsharp mask is really making a grayscale copy of your picture, applying a Gaussian blur...thus unsharp.... Then subtracting the original picture pixel by pixel from the blurred picture and the lighter found values mean an edge is near...lol

Let me say most people will use one of two methods to sharpen. Unsharp mask and Highpass Filter... forget the rest... old technologies mostly. There are many other methods... sharpening masks using find edges and so forth... forget that too for now. Once you gain experience then by all means experiment you can get wonderful results.

I often try both methods above and see which works best… they are simple to apply so why not.

Sharpening is usually applied once all other editing is done but that is not set in concrete. I tend to follow that procedure.

How about if I give you some general settings for both procedures. They will be general but will work most of the time even though I am sure others would give you different values but these are a good starting point. Just pay attention to what is happening to your picture and you will soon come up with your own values.

Unsharp Mask setting;

Amount… 80 to 150 Use the higher amount if the picture will be printed.
Radius….. 0.5 for screen images, 1 to 2 pixels for print images.
Threshold.. 0 most of the time.

Not for sharpening but to increase contrast in a hazed picture for example try;

Amount….30
Radius…...60
Threshold..0

Highpass Sharpening settings.

Highpass Filter…Radius 1 to 4 pixels
Layer mode setting…Try any of the following they will provide different amounts of sharpening.

Overlay
Soft light
Hard light
Vivid light
Linear Light

These settings should give you a good start.

I tend to over sharpen some because I sharpen on a separate layer and I can always reduce the layer opacity.

Unsharpmask and Highpass filter sharpening can be used at any time and are interchangeable. Just see which you like best.

You will know when you apply too much sharpening, you will see halos along the edges. Go ahead and boost the amount just to see... The idea is to increase contrast along edges without producing halos. This will give the illusion of focus human eyes like edges and contrast.

Butch

[Robyn]

Thank you Grant and Butch. I've printed your replies out for future reference.

Butch......I'm too quick.....I've printed it out before your edit!

[Daviskw]

Sorry Robyn I never seem to get it right the first time or the second or third..:p

[kayser]

Butch- I knew you'd come along with a great explanation. Now if I just need to absorb it! And thanks, Grant, I should have expected you to answer this one too. It's nice to have you guys around! :)

[hankalive]

thanks much for your replies everyone. I'll play around a bit and become a practitioner - I like the idea of sharpening in a layer to avoid touching the original - I see it can be done with the high pass filter; forgive me for perhaps an obvious question, but can one use the unsharp mask in a layer or must it be on the background?

Thanks again!

[Grant]

Yes you can use Unsharp Mask on layers and on selections as well. Then by picking the appropriate blend you can heighten the sharpening effect.

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