Photoshop cs5 cho nhiếp ảnh gia part 22 pptx

125 ■ SETTING ACR WORKFLOW OPTIONS AND SAVING FILES of these colors. Further, if you have some clipping—that is, pixels that are at the extremes of the tonal values—in one or more channels, you may want to see whether changing to the ProPhoto RGB space allows you to capture more detail in those chan- nels. The disadvantage is that if you are converting back to an 8-bit image, you may have more colors that need to be converted than if you had limited yourself to Adobe RGB 1998. This may lead to some posterization or banding. Occasionally, some people may want to use sRGB IEC61966-1. This is a nar- rower color space, but it’s useful if your intended output is limited to projection, email, and/or web usage. If you think that there’s any chance you may want to print the file, we recommend you use either Adobe RGB or ProPhoto RGB and convert to sRGB for the specific use. (See Chapter 4, “Foundations,” for a more complete discus- sion of color spaces.) ColorMatch RGB is a space that is wider than sRGB and narrower than Adobe RGB. This means it may have more colors than you can utilize for web use or projec- tion but fewer than your inkjet printer is capable of printing. Therefore, one of the other spaces is usually a better choice. Choosing the Depth You have the choice of converting your image into a file with 256 possible tonal val- ues (8 bits per channel) or a file with 32,768 possible values (16 bits per channel). The clear advantage to 16-bit is accurate and smooth reproduction of tonal variations. The workflow is as easy for a 16-bit file as for an 8-bit file. The only slight disadvantages are that since the 16-bit file is larger, your computer may process adjustments a little more slowly, you may need more RAM to process the files, and the files will take up more space in memory. Choosing the File Size and Resolution ACR provides a drop-down menu, found under the Size option, listing various file sizes specific to the camera used to take the image. Some of the sizes are marked with a plus sign (+) and some by a minus sign (–). One size has neither; it refers to the native resolu- tion of the image with no interpolation. Most of the time this is the choice you’ll want. If you are optimizing images for a slide show, you may prefer to use a smaller size. Some people prefer to use a larger size if they know they will be creating huge files, believing that the interpolation done by ACR is better than the interpolation done later in Photoshop. We have not found any significant benefit to enlarging the file in ACR, and the drawback is that you are dealing with a larger file size that requires more memory space and longer processing times. If you have cropped the image, the sizes available will reflect the crop. In that case you may prefer to use one of the sizes with a +, depending on the magnitude of the crop and the size of your intended output. As we discuss in Chapter 4, the resolution, expressed in ppi (pixels per inch), merely refers to how tightly or loosely packed the pixels are; it doesn’t change any- thing about the total number of pixels. The actual number of pixels is controlled by the file size that you choose. The resolution you set determines whether pixels are 607343c03.indd 125 4/12/10 11:48:38 PM 126 c h a p t e r 3: ADOBE CAMERA RAW ■ distributed 72 to an inch, 300 to an inch, and so on. Since one of the most common outputs is for print, we recommend setting your resolution to your print resolution (usually 300 ppi). That way, when your image opens in Photoshop it is sized accord- ing to an output resolution of 300 ppi. We’ll cover resizing images for print further in Chapter 10, “Output.” “Sharpen For” Options ACR contains several output Sharpening Options, including None and options to sharpen for the screen, or for glossy or matte paper. Then you can specify to use a standard amount, low, or high. We recommend leaving this type of sharpening set to None because we find these options to be rather vague. In addition, this sharpening is applied to the image at full size, whereas your actual output size may vary. In most cases output sharpening is most accurately performed on the image at its intended size. We cover sharpening in detail in Chapter 10. If, however, you want to output directly from Bridge using the Image Processor, then you may wish to take advantage of these options. Opening an Image as a Smart Object If you opt to follow our flexible workflow (see Chapter 5) we recommend checking the option to open the file as a Smart Object. If you prefer to use the traditional workflow, then leave this option unchecked. The Open Image button in the lower corner of the ACR interface will say Open Object if this option is checked or Open Image if it is not. When you’re done with the Workflow Options dialog box, click OK. Most of the time you’ll leave the workflow options set without changing them. The settings are sticky. Finishing Up in ACR After optimizing your image in ACR using as many of the features as necessary to make the file the best it can be, you have four choices: Done The Done button applies the changes but does not open the image. The image is still a raw file, and the changes are still tags. The thumbnail preview in Bridge will reflect the settings you chose in ACR, and those settings will reappear when you reopen the image in ACR. Note: If you are working with a JPEG or TIFF file in ACR, Done applies the changes, but you can see them only when you view the file in ACR. This is because the file itself remains untouched and the changes you made are stored as instructions to that file. To see the changes in Bridge, you will need to use Save. Open Image/Object The Open button applies the changes to the selected image and opens that image in Photoshop. The image is now converted, and the changes are a perma- nent part of the file. To toggle between Open Image and Open Object, hold down the Shift key. 607343c03.indd 126 4/12/10 11:48:38 PM 127 ■ SETTING ACR WORKFLOW OPTIONS AND SAVING FILES Note: In JPEG and TIFF files, the changes you made in ACR are applied to the image when you open it in Photoshop, but you will need to save the file to have the changes remain if you previously checked only Done. Save Image The Save button converts the image and saves it; another dialog box appears, prompting you to choose a location, name, and format (such as DNG, JPEG, TIFF, or PSD) for your converted image. (If you don’t want this dialog box to appear, hold down the Alt/Option key when you click Save.) Cancel The Cancel button closes ACR, and the settings you chose are not retained. Note: Digital negative (DNG) is a universal raw file format developed by Adobe to allow users to archive their raw images in a format that hopefully will continue to be accessible for years to come as converters become more sophisticated. DNG was developed as a response to the ever-increasing num- ber of different raw formats and concerns that files archived in the camera manufacturer’s proprietary raw format may one day be unable to be opened as camera manufacturers abandon older raw formats. The downside to the DNG format is that it’s unable to store some information that exists within the original raw file but is proprietary to the camera manufacturer. Try It! Now that we’ve covered the basics of using ACR, it’s time for you to try it. Open the raw file ConvertRaw on the accompanying website, or open an image of your own. Take the following steps: 1. Begin by dragging the Exposure slider and then the other sliders. Don’t forget to hold down the Alt/Option key while setting the Exposure and Blacks sliders to avoid clipping any pixels. Move the other sliders as needed. Experiment with each of them to become familiar with them. 2. Next, adjust the white balance. Try clicking the eyedropper in various areas to see how it affects the image. Fine-tune your results with the Temperature and Tint sliders. 3. Click the Detail tab, perform any noise reduction that you need, and then experi- ment with the Lens Correction sliders. 4. Use the HSL/Grayscale tab, and create a black-and-white as well as a color version of the image. 5. Select the Brush tool and make several localized adjustments. Be certain to keep an eye on the histogram as you make your adjustments to ensure you don’t accidentally clip any pixels! 607343c03.indd 127 4/12/10 11:48:38 PM 128 c h a p t e r 3: ADOBE CAMERA RAW ■ Batch-Converting Multiple Images If you have a series of images that you want to convert, you can select them all in Bridge and then open them in ACR by double-clicking on one of the selected thumb- nails. Pressing Ctrl+R/F+R will open the ACR dialog box while remaining in Bridge, and pressing Ctrl+O/F+O will open the ACR dialog box hosted by Photoshop. (You can set an option within Preferences in Bridge to indicate whether double-clicking opens the Camera Raw dialog box in Bridge or in Photoshop.) Note: Hosting ACR by Bridge can be a time-saver so that ACR can convert images in the back- ground while you continue to optimize other images in Photoshop. When ACR opens, it opens in Filmstrip mode, as shown in Figure 3.28. The images to be converted appear in a vertical column on the left. Mark images to delete by pressing the Delete key. Those thumbnails will have a large red X on them. Figure 3.28 When selecting multiple images to convert, ACR opens in Filmstrip mode. Selecting a number of images that you want to convert and having them open within a single ACR dialog box can save time. You can choose settings for them indi- vidually, or in Photoshop you can select a group to share some of the same settings. Although you are most likely to want to customize the ACR settings for each image, if you have a series of images that were shot under similar conditions and that need 607343c03.indd 128 4/12/10 11:48:39 PM 129 ■ BATC H- CON V ERT ING M ULT IPL E I MAG ES some of the same settings, batch-converting can be a huge time-saver. To batch- convert a group of images in ACR, take these steps: 1. Click one of the images to select it, and then make all the adjustments you want to perform in ACR. 2. In the left pane, click the image(s) to which you want to apply these same set- tings. To assign the settings to more than one image at a time, Ctrl+click/F+click all the desired files or click Select All. Alternatively, select all the images first and adjust the image that’s visible. ACR will automatically update each image with the same adjustments. 3. Next, click the Synchronize button. A dialog box appears where you choose the parameters you want to copy from the file you just optimized to the other selected files (see Figure 3.29). Sometimes you may want to copy all the changes you made; other times you may want to select only a few, such as white balance or the dust removal. (Yes, you can even copy the retouching!) Figure 3.29 You can choose which parameters to apply to all the highlighted images in ACR in Photoshop by checking them in the Synchronize dialog box. 4. When you have finished, click one of the buttons at the bottom: Save Image, Open Image, Cancel, or Done. For Photoshop Elements Users: Batch Processing Elements enables you to open multiple images into Camera Raw, but it does not have a Synchro- nize button. To adjust multiple images at once, follow the Photoshop instructions but skip Step 3. For Photoshop Elements Users: Batch Processing Elements enables you to open multiple images into Camera Raw, but it does not have a Synchro - nize button. To adjust multiple images at once, follow the Photoshop instructions but skip Step 3. 607343c03.indd 129 4/12/10 11:48:39 PM 4 Ph oto b y Ell E n An on 607343c04.indd 130 4/11/10 11:04:11 PM 131 ■ Foundations 4 Foundations We know that you want to continue work- ing on your images as soon as possible, but there’s some groundwork to be laid. Much of the work you’ll do in Photoshop, and in fact most of the advanced work, involves using the various tools in the Tools panel. In this chapter we’ll introduce you to some of these tools to help you build a strong foundation for the adjustments we’ll cover in later chapters. But before we do that, we’ll help you set up Photoshop so that you can be as efficient as possible. In later chapters, you’ll put these choices and tools to good use, in some cases extensively. Chapter Contents Customizing Settings Views and Zoom Selection Tools Brush Tools Building Tool Knowledge 607343c04.indd 131 4/11/10 11:04:11 PM . capable of printing. Therefore, one of the other spaces is usually a better choice. Choosing the Depth You have the choice of converting your image into a file with 256 possible tonal val- ues. the changes to the selected image and opens that image in Photoshop. The image is now converted, and the changes are a perma- nent part of the file. To toggle between Open Image and Open Object,. dialog box hosted by Photoshop. (You can set an option within Preferences in Bridge to indicate whether double-clicking opens the Camera Raw dialog box in Bridge or in Photoshop. ) Note: Hosting