Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Adobe Photoshop > Technique

  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

The Unsharp Mask Filter

Step 17: If you are going to resample your image by either adding pixels to make it bigger or removing pixels to make it smaller, you should do that first before sharpening your file. In the Image/Image Size dialog, if you are just changing the Pixels/Inch with the Resample Image option turned off, this should not affect the sharpening of an already sharpened file as you are not adding or removing pixels.

Choose Image/Duplicate (F5) to make a copy of this master layers file called KansasVersion1, turning on the Duplicate Merged Layers Only option and then choosing OK in the Duplicate dialog. Type an F to put this single layer copy in Full Screen mode. Now you will use Filter/Sharpen/Unsharp Mask to sharpen your image for final output. The Unsharp Mask filter has three different settings (Amount, Radius, and Threshold) that affect different parts of the sharpening process. You will have to run some tests to determine what value to use in each of these settings. It is often useful to compare tests on a small section of the image. Photoshop does have a Preview button in the Unsharp Mask filter that allows you to see the effect on a selected area of the image, but it doesn't allow you to compare one group of settings to another. Once you get familiar with the amount of sharpening you like on your various types of prints, you can turn the Preview button in the Unsharp Mask dialog off and on while trying different settings to decide the amount of sharpening you want. Turning the Preview button off and on will change the part of the image that is visible on your computer screen from not sharpened to sharpened. The small window inside the Unsharp Mask filter will always show part of the image as sharpened, but if you click down and hold inside that little window, that part of the image will toggle to unsharpened. Click anywhere in your image to reset what actually shows within this window inside the Unsharp Mask filter.

Figure 20.32Figure 20.32 Step 17: The Unsharp Mask filter dialog box with the settings I used to sharpen my KansasVersion1 file.


Another technique for sharpening very saturated files is using Image/Mode/Lab Color to convert the file to Lab Color mode and then sharpening the L channel. This method prevents your saturated colors from popping too much during the sharpening. You can actually print to an Epson printer directly from Lab color so you don't need to convert back to RGB. Another sharpening option is to just sharpen one of the RGB channels.

A good way to compare different sharpening settings is to use the Marquee (M) to select a section of the image that can represent the entire image, and whose sharpness is most important, and make a copy of it using Edit/Copy. (See the images on the next page to see what I selected from this photograph.) Now choose File/New (Command-N) to create a new file. Because you just made a copy, the new file will be the size of the copied section. Click OK in the New dialog box and then do Edit/Paste (Command-V). Repeat this action several times, until you have five or six small files that you can place next to each other on the screen for comparison. Now run different tests on each file to see what each of the three parameters of Unsharp Mask do. Speaking of those three parameters, here is what they do:

Amount: This setting controls the overall amount of sharpening. When you compare sharpening effects, you want to zoom in on the image (to 100% and occasionally to 200%) to see all the detail. Compare different copies of the same image area using different settings for Amount. You sharpen an image by looking for edges in the photograph and enhancing those edges by making one side of them darker and the other side of them lighter. Edges are sharp color or contrast changes in an image.

Radius: This setting controls the number of pixels along an edge that you modify when you sharpen the image. Again, try running the filter with different settings and compare several copies of the same image side by side.

Threshold: When you set Threshold to 0, everything in the image becomes a candidate for being an edge and getting sharpened. If you set the Threshold to, say 10, then an edge will only be found and sharpened if there is a difference of at least 10 points (in the range from 0 to 255) in the pixel values along that edge. The larger the value you give to the Threshold setting, the more contrasty an edge needs to be before it is sharpened.

When you find the Unsharp Mask values that look best, use those to sharpen the entire file. If the original image is very grainy, I might increase Threshold, which lessens the sharpening of the grain. If the image is very fine grained, I might decrease Threshold, which allows me to sharpen the file a bit more, without getting more than the normal grain appearance in the final image. You have to be careful not to over-sharpen. If your final output is a halftone, you can get away with more sharpening than you can for a transparency film recorder, or even a digital print output, because the screen angles and dots in a halftone tend to lessen some sharpening artifacts. All artifacts show up if you output to a color transparency film recorder, however. We usually use the Unsharp Mask filter instead of the other Photoshop sharpening filters because Unsharp Mask provides much finer control over the many different types of images.

Another way to sharpen your image and avoid sky grain, which I usually use, is the Sharpen Only Edges BH action script. This is explained in Chapter 11: "Automating with Actions," and also at the end of Chapter 26. You should check it out, as it produces very sharp files without the grain!

Figure 20.33Figure 20.33 Step 17: If you name the layer in your document with the sharpening value you used, that information will help later if you decide the sharpening amount wasn't correct.

Figure 20.34Figure 20.34 Step 17: Image with no sharpening. We need some!

Figure 20.35Figure 20.35 Step 17: Unsharp Mask 150, 1.5, 0. Too much grain!

Figure 20.36Figure 20.36 Step 17: Unsharp Mask 450, 1.5, 0. Too much sharpening and grain!

Figure 20.37Figure 20.37 Step 17: Unsharp Mask 150, 4.5, 0. Too large a Radius for a real look.

Figure 20.38Figure 20.38 Step 17: Unsharp Mask 150, 1.5, 8. I used to use this a lot but now I experiment more on each image.

Figure 20.39Figure 20.39 Step 17: Unsharp Mask 300, .5, 4. Compare this to the ones on either side.

Figure 20.40Figure 20.40 Step 17: Unsharp Mask 500, .5, 8. Let's see how this prints.

  • + Share This
  • 🔖 Save To Your Account

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Peachpit products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive:

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020