I recently had a wedding photographer ask me to try and help explain to them what sharpening is and how to use it. So... I wrote up the following to try and help explain things to him. Let me know if it helps you.

An extremely overly simplified explanation of what sharpening is:

Sharpening in Photoshop basically takes place by PS numerically finding differences in gray levels in an image. Where the gray levels show differences (edges of objects/subjects) PS will sharpen by darkening and lightening on opposing sides of an edge. The light side of an edge will be darkened while the dark side will be lightened. (This is the same basic principal that is utilized in painting in order to give a painting the appearance of being “sharp” or “in focus”)

So, basically sharpening in a digital file is simply tricking the eye into seeing a greater amount of contrast at an edge than in other areas of a photograph. It should be understood that in digital images, sharpness is simply create by the illusion of contrast, this is what allows us to control the sharpening.

Alright, I could go on for days trying to explain more about sharpness in a digital file and what not, but that wouldn’t really simplify sharpening now, would it… (So yes, someone could come along and say I am wrong/incomplete here, but the understanding is, I can’t be perfectly “right” unless I make things complicated.)

So, here is how you can break down sharpening for yourself:

To start out, create a new file in Photoshop at 600x400 pixels.

Make the canvas background white.

Fill half of the file with a middle gray tone.

You will now have a file, one side white, the other side some form of gray.

Zoom in on the file until you are viewing it at somewhere between 400% and 800%

Go to “Filter” “Sharpen” “Unsharp Mask”

Set your “Amount” to anywhere above 100% (This will control the intensity of the sharpening)

Set your “Radius” to 1. (This controls the width of the darkening and lightening affect created by the sharpening in increments of pixels. A radius of 1 = 1 pixel wide sharpening)

Set your “Threshold” to 0. (This controls where the sharpening in a picture will take place. This is done by gray levels. Photoshop determines the difference in gray levels between one spot and another. If you set the “Threshold” to 10, then there must be 10 levels of gray difference between one edge and another in order for sharpening to take affect at any point in that particular file.)

Now that you have everything set up like this you can start by playing with the “amount.” You’ll see this controls the intensity of how strong/bold the sharpening is. Play with the “radius” and you will see how spread-out the sharpening goes.

Playing with the “threshold” is not as obvious on such a file. To see the affect of the “threshold,” you would be better off in an actual photograph. In the file I had you make, the “threshold” will almost appear to affect the file similarly to the “amount,” but in reality, it is a very different control.

In an actual photograph, go in and make adjustments with the radius and the amount, usually the radius will be set between .80 and 1.4ish… there is no perfect number, depends on the image and the output device. Make sure you view your images at 100 percent when sharpening. The amount can be set anywhere, just depends on how much you want to sharpen. I’ve done as little as 100 and as much as 500.

Now is your chance to play with the “threshold.” If you are sharpening someone’s face, but their skin is sharpening too much, and you just want the eyes sharp, raise the threshold up slowly until you see it only affecting the areas you want it to. This is a finicky control, but it works well.

Definitely let me know if any of you find this useful. One problem with sharpening in this way is that it is not easily applied to the Workflow.

Tim,

Me no English good. Please make instruction to Chinese.

Sank you.



Just kidding Tim. I wouldn't expect you to translate this particular email. It's a bit technical. Otherwise I am sure you'll have no problem. Thanks for the breakdown on Sharpening.

Oh my heavens...Tim, do you actually find that fun to do?????? I'd rather shoot than fiddle with that stuff! UGH. I'm so depressed and blue from just thinking about how to sharpen in PS CS now.



KK

Tim does that on every picture we shoot! Just kidding...

As with anything there are many ways to sharpen, some better than others, but use this as a guideline and we'll see if we can get a version of this applied into the next action set from Nitorix so it can be easy and automated!

Don't feel overwhelmed!

Here ya go Regis! Provided by FreeTranslation.com

David, that translation is great. I have to be careful about asking for things on this forum.

The phrase "Ask and you shall receive" is well and alive on this forum.

LOL! I do what I can!

Is that mandarin or cantonese DJ? Your talents just don't end do they ...

ne ho ma

Hahaha!!!

That's freakin hilarious DJ!

-- Gregg

Yikes, looks even more complicated in Chinese.

Lol, yeah, I'll have to post up a more simple way of sharpening here shortly, I'm just waiting for more replies first.

Hi Tim,

What is your opinion on the Nik Sharpener Pro software?

Thanks