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

Home > Articles > Design > Adobe Photoshop

The Photoshop CS5 Pocket Guide: Making Corrections

Even carefully planned and posed photographs can have flaws. Photos you snap on the spur of the moment are even more likely to include distracting background objects or to have less-than-ideal lighting. The good news is that you can improve—and sometimes even perfect—exposure and lighting. You can also often remove unwanted objects, such as phone lines or even people, in Photoshop.
This chapter is from the book

This chapter is from the book

Unless you're working with an adjustment layer, most image corrections involve changing the actual pixels. So, once again, it's a good idea to be working in a copy of the image, leaving your original intact for future use.

Tonal Changes

The tonality of an image includes qualities of lightness, darkness, and contrast. Photoshop includes a full range of tools to correct or enhance the tonality of an image. Some of the tools are fairly straightforward, while others are a bit more complex. They all work essentially the same way, however: they map the original pixel values to a new range of values.

If you're working on an image that you expect to print professionally or for some other reason the image tone is absolutely critical, make sure you've calibrated your monitor and you're using the appropriate color management profile. (For help calibrating your monitor, see Photoshop Help.) Additionally, make changes in the color mode you'll be using for the final output. If the image is intended for the Web, work in RGB mode. If you plan to print the image professionally, either work in CMYK mode or convert to CMYK just before you print. But don't move back and forth between the modes if you can avoid it.

Generally, the following workflow will get you to good results most efficiently:

  1. Remove flaws such as dust spots or scratches before making color and tonal adjustments.
  2. View the histogram for the image to see its quality and tonal range.
  3. Start by adjusting the color balance to remove any color casts or correct saturation.
  4. Adjust the tonal range using either a Levels or Curves adjustment layer. There, you'll set the white point (defining highlights) and black point (defining shadows), and make any necessary adjustments to the midtones.
  5. Finally, make any other color adjustments, such as hue, saturation, or vibrance.

To open the Histogram panel, choose Window > Histogram. The Levels dialog box also displays a histogram.

A histogram shows you how pixels are distributed in an image, so you can see how much detail appears in the shadows (on the left), the highlights (on the right), and the midtones (in the middle). Much of the time, you'll want an even distribution—an image that is neither too dark nor too light. However, in some cases, it's appropriate for the detail to be concentrated in the shadows or the highlights, depending on the mood you want to convey.

Figure 4.1

Figure 4.1 The histogram shows how pixels are distributed. In the first image, there's more detail in the highlights and midtones. The second image has more detail in the shadows, with some in the highlights.

You can perform a generalized color correction using a Color Balance adjustment layer, or you can let Photoshop take a stab at it by using the Auto Color option in the Levels or Curves dialog box. Balancing color removes any color cast, such as a blue or red cast, that may appear in your image.

To add a Color Balance adjustment layer:

  1. Click the Color Balance icon in the Adjustments panel.
  2. Select Shadows, Midtones, or Highlights as an area where you want to focus the changes.
  3. Drag the sliders toward the colors you want to increase and away from the colors you want to decrease. For example, if the image has a red cast, drag the slider away from Red and toward Cyan. Be careful not to overcorrect—you can easily add a color cast using the Color Balance adjustment!

To remove a color cast using the Auto Color option:

  1. Click the Levels or Curves icon in the Adjustments panel.
  2. Click Auto.

The Auto option neutralizes midtones and clips shadows and highlight pixels.

Figure 4.2

Figure 4.2 Use a Color Balance adjustment layer to remove color casts or otherwise adjust color.

Levels

The Levels panel affects the levels of intensity of shadows, midtones, and highlights. It's not all that hard to make the adjustments. The histogram helps you see where the detail is in the image, and there are some rules of thumb for improving it.

In the Levels histogram, the left side represents the shadows, the right side represents the highlights, and the center shows the midtones. The input and output sliders are related, but here's what you need to know to use this adjustment: The left input slider, at the bottom of the histogram, sets the image's black point—the point beyond which all data is seen as pure black. The right input slider sets the white point—the point beyond which everything is treated as pure white. Generally, you'll get better results if you move the left slider to the point where significant shadow data occurs, and the right slider to the point where significant highlight data begins.

The middle slider adjusts the gamma, which changes the intensity of the middle range of gray tones without making large changes to highlights and shadows.

You'll hear photo-editing pros talk about clipping shadows or highlights, something you typically want to avoid. When shadows or highlights are clipped, the pixels are a solid white or black and provide no detail.

Figure 4.3

Figure 4.3 Adjusting levels can be a quick way to punch up the intensity of the color in your image, and to ensure you're seeing the appropriate detail.

To apply a Levels adjustment:

  1. Click the Levels icon in the Adjustments panel.
  2. Drag the black and white input levels sliders to the edge of the first group of pixels at either end of the histogram. Photoshop sets the black and white points at the new position—everything to the left of the black point is solid black; everything to the right of the white point is solid white.
  3. Adjust the middle slider to tweak the midtones. Moving it to the left lightens the image; moving it to the right darkens the image.

To neutralize a color cast using the Levels adjustment:

  1. Click the Levels icon in the Adjustments panel.
  2. Click the Set Gray Point Eyedropper tool.
  3. Click in a part of the image that should be neutral gray.

Curves

The Curves adjustment has nothing to do with the bodaciousness of your subject. You use the Curves adjustment to make more gradual changes throughout the tonal range than you can through the Levels adjustment (which has only three points of adjustment: black, white, and gamma). Why curves? Because the adjustments appear on a graph, and as you adjust the tonal range, you're adjusting the curve of the line.

The horizontal axis of the graph represents the input values; the vertical axis represents the output values. Initially, the tonal range is represented as a straight diagonal baseline because the input and output values are identical. By default, the Curves graph shows the amount of light, so moving the curve upward lightens the image and moving it downward darkens the image. The steeper sections of the curve represent areas of higher contrast, and flatter sections represent lower contrast. Moving a point in the top portion of the curve adjusts the highlights; moving a point in the center adjusts the midtones; and moving a point in the bottom section adjusts the shadows. You generally need to make only small curve adjustments to correct the tone and color in an image.

Figure 4.4

Figure 4.4 Adjust the curves to make more gradual changes through the tonal range.

To adjust curves:

  1. Click the Curves icon in the Adjustments panel.
  2. Add a point on the curve by clicking directly on it. You can add up to 14 points to a curve.
  3. Use the black point and white point sliders to set the black and white points. Typically, you want the black point to be at the point that the shadow data appears, and the white point to be at the point that the highlight data appears.
  4. Click a point, and drag the curve until you're satisfied with the tone and color of the image. Or, enter new values for the point in the Output and Input boxes.

You can also select the On-image adjustment tool, and then click the area in the image you want to adjust. Drag the point up or down to lighten or darken the values for all similar tones in the image.

Vibrance

The Vibrance adjustment saturates the colors that need it while leaving the colors that are already saturated alone. It's particularly useful if you're working with an image that contains skin tones, as it keeps them from becoming oversaturated.

  1. Click the Vibrance icon in the Adjustments panel.
  2. Drag the Vibrance slider to increase or decrease color saturation.
  3. To apply the same amount of saturation adjustment to all colors (even those that are already saturated), move the Saturation slider.
Figure 4.5

Figure 4.5 Adjust the Vibrance slider to intensify some colors without oversaturating others.

Correcting shadows and highlights

If an image was taken with strong backlighting, resulting in silhouettes—or if the subject of the image was too close to the flash and ended up kind of washed out, the Shadows/Highlights command may be your best bet for correction. The Shadows/Highlights command doesn't just lighten or darken an image; instead, it lightens or darkens each pixel based on nearby pixels in shadows or highlights. You can make adjustments to shadows and highlights separately. The defaults are set to fix images with backlighting problems.

To adjust image shadows and highlights:

  1. Choose Image > Adjustments > Shadows/Highlights.
  2. Move the Amount slider or enter a percentage in the Shadows or Highlights box. Larger values lighten shadows more or darken highlights more.
  3. Click OK when you're happy with the adjustment, or select Show More Options and make fine-tuned adjustments.

Selecting a variation

If you're overwhelmed by tone correction options, or if you're not sure what might make a particular image look better, try the Variations command. The Variations dialog box shows you alternatives that present different color balance, contrast, and saturation settings, so you can select the one that achieves the look you want.

Figure 4.6

Figure 4.6 Correct lighting issues using the Shadows/Highlights adjustment; select Show More Options to tweak the settings further.

  1. Choose Image > Adjustments > Variations.

    The Variations dialog box shows two thumbnails at the top of the dialog box: the original settings and the current selection. The current selection thumbnail changes as you make choices.

  2. Select what to adjust in the image. You can adjust shadows, midtones, or highlights, as well as saturation.
  3. Drag the Fine/Coarse slider to change the amount of each adjustment. (Each tick doubles the adjustment amount.)
  4. Adjust the color and brightness:
    • To add a color, click the appropriate thumbnail.
    • To subtract a color, click the thumbnail for its opposite color.
    • To adjust brightness, click a thumbnail on the right side of the dialog box.
Figure 4.7

Figure 4.7 Visual types, take heart. You can see the effects of different color and contrast options in the Variations dialog box.

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.

Overview


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.

Surveys

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.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email ask@peachpit.com.

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.

Security


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

Children


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

Marketing


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 customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


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: www.peachpit.com/u.aspx.

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 NevadaDesignatedRequest@pearson.com.

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.

Links


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