50 FAST PHOTOSHOP" CS TECHNIQUES- P5 pptx

While this technique isn't particularly exciting, it is an essential one to make your photos look as good as they can. For this reason, in this technique you learn three dierent approaches to sharpening images, and you get more information on the "hows" and " whys " than most techniques in this book. The three Wer- ent approaches covered are: rn Using Unsharp Mask on the entire image rn Sharpening one or more channels instead of the entire image rn Convert image to LAB mode and sharpen only the Lightness channel I should point out that the best way to get sharp images is to use a high - quality, high - resolution digital camera with a sharp lens - then you usually still need to sharpen the image digitally. Although it would be nice, I am sad to report you can not sharpen an out- of - focus digital photo. In fact, when using the follow - ing sharpening techniques, you'll quickly realize that we are not really sharpening them at all. Instead, we are creating the illusion that they are sharp by digitally emphasizing " edges " in the image by making one side of an edge lighter and the other side darker. As you soon discover, the illusion effect we use to make an image appear sharp is resohtion dependent. This means that you should not apply sharpening effects to an image until you know what your final output will be. A sharpened high - resolution image won't have the optimal amount of sharpening if it is down - sized to be used as a low - resolution image on a Web page or vice - versa. Consequently, sharpening ought to be one of the last steps in your worknow. One other reason to leave sharpening as one of the last steps in your workeow is that the " sharpening effect " will likely be removed or damaged, if you first sharpen your image and then use a variety of other commands and filters. USING UMSHARP MASK ON THE ENTIRE IMAGE STEP 1: OPEN FILE Choose File X- Open (Ctrl+O PC, Cmd+O Mac) to display the Open dialog box. Double- click the \ll folder to open it and then click the gat-before.TIF file to select it. Click Open to open the file. A few minor adjustments have already been made to this image using Curves and Hue/Saturation to enhance the image so that this technique can be devoted to sharpening - a most important topic for digital photographers. STEP 2: DUPLICATE LAYER Before taking any steps to sharpen an image, first duplicate the layer. Not only does this duplicate layer make it easy for you to switch between " before sharp - ening " and " after sharpening'' images so that you can view the differences, but it also allows you the option of " painting " back in some of the original image, or using a mask or selection to limit what is or isn't sharpened. Additionally, you can blend the Background layer with the sharpened layer by using one or more of the Blend modes to further improve the sharpness of the image. Choose Layer * Duplicate Layer to get the Duplicate Layer dialog box. Type Sharpened in the As box and then dick OK STEP 3: SET UP IMAGE VIEW Any time you use the Unsharp Mask, view your image at 10096 to get an accurate view of the effects. SharpeningDigital Photos rn Choose View % Actual Pixels (Alt+Ctrl+O PC, Option+Cmd+O Mac). rn Press the Spacebar to get the Hand tool and click and drag the image until you can see the goat's face where the image is most sharply focused. This is the key area to watch as you apply effects. STEP 4: APPLY UNSHARP MASK Now we get to this seemingly misnamed filter - the Unsharp Mask. If you have never used the Unsharp Mask because you always want to sharpen an image when you select the Sharpen menu - not un - sharpen your image - you are not the first to avoid using one of the most valuable tools for sharpening images! The name comes from a pre - digital darkroom technique where a blurry version of a contact negative was lay - ered with the original contact negative. The result of combining these two " layers " was a pronounced edge contrast, making the image appear to be sharper. As the Unsharp Mask works in the same way, it is appropriately named and it is the best tool for the job - period! rn Choose Filter * Sharpen * Unsharp Mask to get the Unsharp Mask dialog box shown in Tne unsnarp Mask has the following three settings: rn Amount: This control determines how much the contrast increases in percentage terms ranging from 0% to 500%. This setting might also be con - sidered as the intensity or efectstrength setting. rn Radius: Measured in pixels, Radius determines how wide the " sharpening effect " is.You can choose a setting between 0 pixels and 250 pixels and even in parts of a pixel, which is important when you are using values under 5 pixels, which you do most of the time. rn Threshold: This control lets you set the starting point for when sharpening occurs.You can choose from 0 to 255 levels difference between two touch - ing shades. When Threshold is set to 0, everything gets sharpened. When Threshold is set to 255, nothing gets sharpened Using the optimal Threshold setting, you can usually prevent grain, scanner noise, or important image texture from being sharpened. The Unsharp Mask is actually creating a halo effect around edges. It creates a lighter shade on one side of what it thinks is an edge, and a darker shade on the other side, thereby creating the illusion of a sharp edge. Amount determines how bright the halo is, Radius determines how wide the halo is, and Threshold is the minimum shade difference required before a halo is created. A good approach for getting optimal settings when working with high-resolution images is to set Amount to 175%, Radius to 2, and Threshold to 0. Most high-resolution images require an Amount set - ting in the range of 150% to 200%. Generally, Radius values are less than 2.0 and each tenth of a pixel can be significant. Setting Threshold to 0 means that every edge gets sharpened and for now that is okay as it is the easiest setting to adjust after the other two settings are determined. The tricky part is determin - ing the right combination of Amount and Radius. rn Set Amount to 175%, Radius to 2, and Threshold to 0. rn Depending on the image, it may be better to define the edges with a narrower, but brighter halo. Other images may look better with a wider, but less bright halo. See what you think looks best for this one by sliding the Amount from 100% to 200% and lower Radius to around .5 to 1.0. These settings can dramatically alter how realistic the bristly hair on the goat looks. Sadly, in spite of how good you think the sharpening effect looks, the best way to determine the success of your set - tings if you are going to be making a print is to make a print Once you get used to the settings that make good prints, you will be able to more accurately judge the settings you see on a com - puter screen. m As you change settings, click the Preview box in the Unsharp Mask dialog box to view the image with and without the sharpening effect Also, click inside the Preview box to get the Hand tool. Click and drag the image around to view areas where you want to make sure the settings work m As soon as you have a good combination of settings for Amount and Radius, look around the image for an area where there is other he texture. You can now slowly slide the Threshold slider toward the right until you remove the unwanted sharpening effect on the smoother areas. rn Por this image,I set Amount to 125%, Radius to .7, and Thrrshold to 0. Any larger values for Amount and Radius seemed to more than double the width of the sharply focused hairs on the goat's neck. A quick print confirmed that these were pretty good settings. rn Click OK to apply the settings. rn Because you did all the sharpening in the sharp - ened layer, you can now click the Layer Viibility icon (the eye icon) in the left column of the Layers palette to view the difference between the original image and the sharpened image. rn If you want to reduce the effects, choose Edit * Fade Unsharp Mask (Shift+Ctrl+F PC, Shift+Cmd+F Mac) to get the Fade dialog box shown in Figure 1 1.4. As you slide the Opacity slider toward the left, the sharpen effects fade. Besides using Normal, you should also try using the Luminosity blend mode. rn Click Cancel to cancel the Fade settings. At this point, our dear old goat friend looks much better than he did before the Unsharp Mask was applied. In this example, we have applied the Unsharp SharpeningDigital Photos Mask to the entire image. Occasionally, you may work on an image where you don't want the entire image to be sharpened. Using the Quick Mask, a Layer Mask, or a selection tool of your choice, you can easily select and remove or even change the Opacity of the sharpened layer, leaving the unsharp- ened layer below as part of the viewable image. Now that you have a good understanding of how to use the Urnharp Mask, here is one other approach to sharpening an image that is worth trying. SHARPENING INDIVIDUAL CHANNELS Some lower - end or older model digital cameras pro - duce enough digital noise that it becomes difficult to sharpen an image without also sharpening and accen - tuating the unwanted noise, too. There are also images where it is hard to differentiate between important image texture or detail and the " edges " that you want to sharpen. In these and other cases, you want to take a look at each of the color channels to see if you can find one that holds most of the edges that you want to sharpen, but not much of the unnecessary detail. Typically, the lightest channel is the one that you want to sharpen, as it is also the one with the least amount of noise. Some images have two channels that you may want to sharpen. If so, beware that applying different set - tings can cause some rather unusual things to hap - pen. My suggestion is to use the same settings if you are going to sharpen two channels. SHARPEN LIGHTUESS CHANNEL IN LAB MODE Another sometimes useful approach to sharpening an image is to first convert the image to Lab Color mode by selecting Image*Mode*Lab Color mode. To view the Channels palette if it is not already showing, select Window * Channels. The Lab Color mode allows you to separate the color information in an image from the black and white image informa - tion. When viewing an image that is in Lab Color mode, the Channels palette will show a Lightness channel, and an a and b channel, as you can see in Figure 11.5. As the Lightness channel only contains black and white image information it makes an excel - lent channel for applying the Unsharp Mask filter. Once you have applied the setting you want, you can change the mode back to RGB by selecting Image 9 Mode x- RGB Color. To learn more about image sharpening, read Technique 39. 1.1.1.11 Lightness This page left blank CORRECTING COLOR WHEN USING 12 A GRETAGMACBETH COLORCHECKER I ABOUT THE IMAGE ! Veritable Benedictine and Martel Cognac Canon EOS Id mounted on a tripod, 702wmrn f12.8 IS. ISO 200, fl9.0 @ 116, RAW setting, 2.160 x 1,440 pixels, edited and converted with Camera RAW to 266K 1,531 x 1,024 .jpg ' hen getting accurate color is essential and you know that requirement in advance, you should first take a photo that includes a GretagMacbeth ColorChecker Color Rendition Chart (see Figure 12.1) under simi - lar lighting conditions as your final shots. Then, using Adobe Photoshop CS you can easily determine what setting adjust - ments you need to make to " color correct " the entire set of digital photos. In this technique, you will learn how to use Adobe Photoshop CS's Levels command and the Info palette along with the GretagMacbeth ColorChecker to determine the Levels settings to be applied to the Benedictine and Cognac photo shown in Figure 12.3 to get excellent color, as shown in Figure 12.2. 97 Chapter2 Correa.ngand Enhancing DigifaIPhotos Y " STEP 1: OPEN FILE rn Select File * Open (Ctrl+O PC, Cmd+O Mac) to display the Opk dialog box. After locating the \12 folder, double - click it to open it. Press Shift while clicking the Macbeth-chart.tif and bottles-before.tif images to select them both. Click Open to open both 6les in Adobe Camera RAW. Click OK to open both images using the default values. GretagMacbeth ColorChecker 8 " x 11.4 " charts an available at most professional photo stores. One good online source is www. bhphotovideo . corn. The full - size chart costs around S7O.There is also a smaller version,tw. STEP 2: CHECK COLOR rn It now appears that both of these images suffer 4 from a blue color cast that needs to be removed. , To learn more about the color cast, didc the Eyedropper tool (I) in the Toolbox In the Options bar, select 5 by 5 Average as the Sample size to get a good average reading. a If the Info palette is not already visible select Window * Info (F8) to display the palette. To be able to easily read the tonal value in percentage grayscale, click the menu bunon in the Info palette and select Palette Options to get the Info Options dialog box Click in the Mode box beneath Second Color Readout and choose Grayscale. Click OK to apply the settings. The Info palette will now show RGB values and a K value for grayscale ranging fiom 0% as pure white and 100% as pure black. rn Click one on the Macbeth chertjpg image to make it the active image. Drag the Eyedropper tool over the white square, which is the bottom - left square in the chart. The Info palette will show you values similar to the ones shown in Figure 12.4. R (red) should be 246, G (green) should be 252, and B (blue) should be 255.You may get slightly differ - ent values depending on the placement of the cur - sor. This means that there is much more green and blue in the image than there is red; hence, the color Correch'hg Color When Usinga GretagMacbeth ColorChecker cast. The goal is to have the white square show equal values of red, green and blue. STEP 3: SET COLOR SAMPLER POINTS To be able to read " before " andUafter"values in both the white and black areas of the image when using the Levels command, we need to set a Color Sampler point in both the black and white squares To set a point in the white square, press Shift and click in the white square with the Eyedropper tool (I). To set a point in the black square, do the same - press Shift and click in the black square. Notice that you now have two Color Sampler points in the image: one in the white square and one in the black square. rn Your Info palette should now looklike the one shown in Figure 12.5. You now have two addi - tional points: #1 and#2. STEP 4: CORRECT COLOR USING LEVELS rn We are now going to use the Levels command to remove the color cast. Select Image * Adjustment X- Levels (Ctrl+L PC, Cmd+L Mac) to get the Levels dialog box. rn Our objective is to set each of the R, G, and B values to be equal to the highest value in the white zone, and the lowest value in the black zone. Looking in the Info palette in the #1 readings area, you will now find two values next to R, G, and B. These values are the before and after adjustment values. As these readings are for the white zone, we want to make adjustments with Levels to make the R value equal to 255, the highest value, and G to also be equal to 255. To make the R value equal to 255, click in the Channel box in the Levels dialog box and select Red (Ctrl+l PC, Cmd+l Mac). Click the high - light slider (the white slider; the white triangle slider just beneath the histogram on the far right. Drag the highlight slider toward the left until you see the second value following R in the Info palette reads 255. rn To make the G value equal to 255, click in the Channel box in the Levels dialog box and select Green (Ctrl+Z PC, Cmd+2 Mac). Click the high - light slider and drag it toward the left until you see the second value following G in the Info palette reads 247 or very close. That completes the wlor corrections in the white zone. rn We now need to do the same thing in the black zone, except this time we will be setting each value to be equal to the lowest value found in the black zone. Looking at the Info palette in the point #2 area, you will find that the lowest value is now 83 in the red channel, whereas green is 85 and blue 88. To make the G value equal to 83, click in the Channel box in the Levels dialog box and select Green (Ctrl+2 PC, Cmd+2 Mac). Click the Shadow Slider and drag it toward the right until you see that the second value following G in the Info palette reads 83 or very dose. To make the B value equal to 83, click in the Channel box in the Levels dialog box and select Blue (Ctrl+3 PC, Cmd+3 Mac). Click the Shadow Slider and drag it Using a GretagMacbeth ColorChecker Color Rendition Chart and Technique 12 is a quick and accurate way to remove color casts so that a photo accurately reflects the original colors. However, you may not always want to remove a color cast. If you intentionally shot a photo In early morning or lateevening lightor In candle - light or in other desirable lighting conditions - you will generally havea color can.In theseand other cases, such color casts may be desirable and you therefore will not want to correct the color as you will remove the colorcast while attempting to accurately reflect the original colors. toward the right until you see that the second value following Gin the Info palette reads 83 or very dose. That completes the color corrections in the black zone. rn Before closing the Levels dialog box, we will save these adjustment settings so that they can be easily applied to the photo with the two bottles to make a quick and accurate color correction. Click Save in the I dialog box to get the Save dia - log box. Type bottles in the File Name box and click Save. The image now accurately rdects the color of the original scene. Click in the Preview box to see the difference between the "beforenand " after " images. Click OK to apply the settings. STEP 5: APPLY COLOR CORRECTION SETTINGS TO OTHER IMAGES m Click once on the bottles-before.tifimage to make it the a& image. Select Image * Adjustments WLeveIs (Ctrl+L PC, Cmd+L Mac) to get the Levels dialog box. Click Load and select the bottlesdv levels correction settings file that we created in Step 4; dick OK to apply the set - tings. This image has now been color corrected. Figure 12.2 shows the results of making a few additional changes with Levels and bes to increase tonal range and to brighten the image. USING METADATA lLaq 13 Swift River in White Mountain National Forest Canon EOS 1 Ds mounted on a tripod.200mm f12.8 with 3- stop NDfilte~lSO 100.f122 @ 1 second, RAW setting.4.064 x 2,704 pixels.8.2MB .CRW 0 ne of the luxuries of working with digital files is that there is a growing list of ways in which the image itself can be enhanced by textual content that is written into the image file itself, or saved in a separate but matched file in the same folder. Whiie your initial reaction may be, " So what! " this technique will show you just a few ways in which you can read the shooting data and view, create, and edit metadata to make your dig - ital photos even more valuable. Finally, you will learn how to have Adobe Photoshop CS document your edit steps for you in a textual file format. STEP 1: LEARN HOW TO READ " SHOOTING " DATA One of the most valuable features of digital cameras is that they write " shooting " data about each camera setting into each image file. If you are used to shooting with a film camera, you'll appreciate just how valuable it is to be able to take lots of pictures without making any notes about your camera settings, and then sit down in the comfort of your home or office 101 [...]... a way for Adobe Photoshop CS to document each edit step that you take Sure, you can use the History palette to see what you've done as long as you have a document open; I but, you are in trouble if you need the edit histo once you dose a file Now, Adobe Photoshop CS has a feature to document your edit steps To use it, yon just have to t r it on un m To have Adobe Photoshop CS automatically document...and view each photo you've taken along with all the camera settings that were used for each of the photos! Adobe Photoshop CS provides you with three different ways to read the "shooting"data, which is technically called EXIF data The easy way is to open Adobe Photoshop CSs Pile Browser.To do so,you can either select Window*File Browser, or you can click the File Bmwser icon in the middle of the... and white images turn out when converting digitally with Adobe Photoshop CS that you may decide it is not worth shooting black and white film ever again Chapter3 Working in Black and Wkia There are at least seven basic approaches and many variations to convert a color image into a black and white image using Adobe Photoshop CS They are as follows: 1 Convert image to black and white by convert- ing... filters Plus, fantastic new monochrome ink sets and revolutionary new inkjet printers are becoming available that produce excellent black and white prints with archival qualities and print characteristics that rival or those of traditional chemical-based photo prints If you enjoy Mack and white photo &uIl enjoy ti chapter hs The first technique gives you a good several ways you can convert color images... pixel, 4.4MB grayscale tif I 1 52 0 ZOO2 Phil Bard n the darkroom, black and white printers alter contrast and dodge and burn (lighten and darken) to improve the looks of their prints Adobe Photoshop CSs Adjustment Layers and Layer Masks now make these techniques possible digitally with much more precision, control, and the flexibility to go back and make changes Rather than making a permanent change . Photoshop CS provides you with three differ - ent ways to read the " shooting " data, which is techni - cally called EXIF data. The easy way is to open Adobe Photoshop CSs. dose a file. Now, Adobe Photoshop CS has a feature to document your edit steps. To use it, yon just have to turn it on. I m To have Adobe Photoshop CS automatically document your edit. Threshold to 0. Most high-resolution images require an Amount set - ting in the range of 150% to 200%. Generally, Radius values are less than 2.0 and each tenth of a pixel can be