Sharpening

•Every image needs sharpening.
•You cannot sharpen an out of focus image.
Start with a sharp image and sharpen from there.
You will be amazed...

The name “Unsharp Mask” comes from an old-school analog technique where you created a duplicate negative that was slightly out of focus (unsharp) and then sandwiched it together (mask) with your original negative to make your print. The magical result was increased contrast around edges, creating the illusion of greater visual sharpness.

Objective:
•To explore the many sharpening techniques and to see firsthand what technique works best with
different types of images
•To analyze and draw conclusions from the examples created.

Overview:
PART 1 -Techniques for Sharpening
•Choose ONE image to sharpen
•The image should be color corrected and cleaned up before sharpening.
•Save As, flatten the file, size the file
     (2160px on the longest size 240ppi, 8bit)
•For each sharpening technique create a duplicate file of that one image and apply the technique
•Save files as a .psd, do not flatten the layers. I want to see the sharpened layer over the unsharp layer.

TitleFile: Bold.psd (ex: original.psd, lum.psd)
1) Unsharp mask   (Name Last_ first initial_ Unsharp.PSD)
2) Lab Sharpening    (Name Last_ first initial_ Lab.PSD)
3) Luminosity sharpening
4) Layer sharpening
5) High Pass Sharpening

PART 2 -Creative Sharpening -You will be using your layer masks here.
•Choose 5 different images that you want to explore creative sharpening on (sharpening a portion of the image not the whole, using a layer mask)
•The image should be color corrected and cleaned up before sharpening.
•Save As, flatten the file, size the file
     (2160px on the longest size 240ppi, 8bit)
•For each creative sharpening file create a Background copy layer to sharpen and add the layer mask to.
TitleFile:
Name Last_ first initial_ creative1.PSD
Name Last_ first initial_ creative2.PSD
Name Last_ first initial_ creative3.PSD   ETC.

Turn in
•10 images through Canvas
•Each image should have 2 layers. A background unsharpened layer and a duplicate background sharpened layer. No layer mask for part 1 - with layer masks for part 2.
•Email me in the body of an email (no word files or PDF's)  hhprotz@cox.net
-Conclusions as to what you see in the sharpened files, do you see any differences between the techniques? Do you like one over the other? Include your thoughts on the creative sharpening as well.

An Exercise before sharpening a real Image:

•Open Photoshop and create two adjacent gray blocks
(it doesn’t matter what size).
•The lefthand block should have the RGB value of 86, 86, 86 (in Photoshop, double click on the foreground color in the tool palette, then enter those values directly into the RGB section of the Color Picker that appears).
•The righthand block should have the RGB value of 43, 43, 43. Be sure that these blocks touch one another, and that you’ve turned off any anti-aliasing options in the tools you used to create them.
•Zoom way in on your image (500-1000%). You want to see the transition line between the two blocks clearly, so place it in the middle of your window.

•Photoshop: Filter->Sharpen->Unsharp Mask).
Select Unsharp Mask from the Filters menu and set starting values of 100 for Amount, 2 for Radius, and 0 for Threshold.

Amount: determines the aggressiveness of the "sharpening" action. With your simple two-gray image, try amounts of 100, 200, and 400 (make sure the Preview box is checked in the Unsharp Mask dialog so that you see the changes as you make them; you should also be viewing at Actual Pixels size). What you should see is that as the amount is increased, the colors of the new edges get more exaggerated. In other words, the light line that gets added on one side of the boundary gets lighter with each increase, the dark line on the other gets darker (though that’s often more difficult to see).

Radius: determines how wide an area at the transition is affected. Try increasing the Radius to 4 and 8, and you’ll see that area that is modified at the transition widens. Note, too, that the further away from the actual transition point you get, the less the Amount is applied.

Threshold: determines how much difference there must be between two adjacent pixels before any change is made. In our simple example, you’ll have to enter very high numbers before you see how this works (try 25, 50, and 100). Note that threshold and radius interact a bit. With a Threshold of 100 and a Radius of 1 or less, almost nothing changes, but if you increase the Radius, you’ll start to see the effect again.

If you found this exercise helpful, go check out the rest of the article.
http://www.bythom.com/sharpening.htm


•Sharpening is the last step before printing.
•Make a duplicate file.
•Size the file for printing.
•Then apply the desired sharpening technique.
•Sharpening will affect the contrast, making the image more contrasty
•How will sharpening affect the noise or grain in the image?

The Sharpening starts here:
Always Duplicate your Background Layer.
If you over-sharpen you can reduce the opacity of your sharpen layer.

•••When Sharpening, Bring your image to 100% magnification on screen (Double click the zoom tool) use the move tool (hand) to scroll around to an area you can see the sharpening effect•••

•Unsharp Mask
1) Filter - Sharpen - Unsharp Mask

With your image at 100% magnification experiment with the numbers and see the effects. All Images will have different settings. For my images I usually use an Amount setting between 50-100, the Radius 1-4 and the Threshold 0-3. Some people push this up to 5.
You will find that different types of images have different sharpening parameters. I have seen others who swear by a totally different
approach. Whatever works... this is our starting point.

••Lab Sharpening
1) Image - Mode - Lab Color
2) Channels Panel - click the lightness channel
It will then be highlighted
3) Filter - Sharpen - Unsharp Mask
At this point you will only be sharpening the black and white lightness channel avoiding the problem color
halos that pop up in the RGB sharpening approach.
4) Image - Mode - RGB Color

•••Luminosity Sharpening
1) Filter - Sharpen - Unsharp Mask
2) Edit - Fade Unsharp Mask
3) In the dialogue box change MODE to Luminosity
4) Click OK
The sharpening is now only applied to the luminosity not to the color data

••••Layer Sharpening
This avoids noise and color shifts
1) Image - Duplicate
2) Click OK
3) Duplicate Background Layer  (Command - J)
4) Change the Blend Mode of the duplicated Layer to Luminosity
5) Filter - Sharpen - Unsharp Mask
6) Duplicate the Sharpened Luminosity Layer (Command - J)
7) Filter - Blur - Gaussian Blur
-Enter a pixel setting of “3”
-Click OK
The blur takes care of exaggerated noise and halos from sharpening.
8) Change the Blend Mode from Luminosity to Color, this gets rid of the blur.
9) For this exercise leave layers,  If you were when printing flatten the file

•••••High Pass Sharpening
1) In the Layer Panel select your Background Layer and create a duplicate. (Command “J”)
2) With this new layer highlighted go to the menu and select Filter - Other - High Pass.
Set the Radius to 10 and click OK. Zoom into your image to 50% or 100% so you can better see what you’re going to do next.
3) Go back to the Layer Panel and select Hard Light, Soft Light or Overlay from the
Blend Modes drop down menu. Which do you like, I generally choose soft light
4) In the Layers Panel go to the Opacity Slider and select a level of sharpening that
seems best to you.

-Some believe you should move the radius slider to the first point you see color information, try this, experiment.

Applying Creative Sharpening to the image
1) Make a duplicate layer of the background
2) Sharpen the background copy
3) Click the layer mask icon
4) Depending on what you want to sharpen? (less of the image you can command “I” to hide the sharpened layer and paint with white in the area you want sharpened) or do not inverse and paint away with black where you do not want sharpening
Remember when painting on a layer:
    •Black conceals
    •White reveals

Scott Kelby generic Unsharp Mask #’s
LOW
amount - 100
radius - 1
threshold - 10
edit - fade unsharp mask - mode - luminosity

MEDIUM
amount - 85
radius - 1
threshold - 4
edit - fade unsharp mask - mode - luminosity

High
amount - 120
radius - 1
threshold - 3
edit - fade unsharp mask - mode - luminosity

I have these set up as actions to quickly sharpen for the internet, etc.

More Scott Kelby suggested #'s using Unsharp Mask (USM) in Photoshop.

Subject Amount Radius Threshold
Soft subjects 150 1 10
Portraits 75 2 3
Moderate sharpening 225 0.5 0
Maximum sharpening 65 4 3
All-purpose sharpening/medium sharpening 85 1 4
preparing for Web 400 0.3 0

I like to set the radius to be about 1/2 visually from the amount and threshold
ex:(these are just sample numbers)
amount 60%
radius about 3.0
threshold 0

•There are many theorys out there for sharpening, explore and have fun!