Tài liệu Photoshop cs5 by Dayley part 28 ppt

n XMP When you change a supported file format using Camera Raw, those changes are saved as metadata so your settings are permanent unless you want to change them.. The caveat is that eve

Camera Raw File Types

I’ve already explained that there are as many or more camera raw file types as there are camera brands that capture them Some of the more notable ones are Canon’s formats (CR2, CRW), Nikon’s formats (NEF, NRW), and Sony’s formats (ARW, SRF, SR2), just to name a few Your cam-era has its own format, and you should get to know the ins and outs of that particular format because no two are exactly alike If you have a newer or less common format, you may want to be sure you can open your files in Camera Raw You could look for supported formats, but the easiest way is just to try to open a photo in Camera Raw If it works, you’re good to go

Note

Adobe is constantly updating the supported raw formats If your files don’t open on the first try in Camera

Raw, make sure you’ve installed the latest updates n

XMP

When you change a supported file format using Camera Raw, those changes are saved as metadata

so your settings are permanent unless you want to change them The caveat is that even though Adobe can access many camera raw file formats, they are still proprietary, so Adobe can’t change

those files Adobe gets around this by creating a second sidecar file that contains the new metadata

This sidecar file has the extension XMP When you start to see these files floating around in your photograph folders, you’ll know what they are Don’t worry about them too much; they are called sidecar files for a reason They are connected to the camera raw file they interpret and move right along with it if you save it in a different location

DNG

No matter what raw format your camera supports, if Adobe supports it, you can convert your files

to DNG files

The DNG file extension stands for Digital Negative, and it is Adobe’s own camera raw format

Many proponents are fighting for it to become an industry standard This would alleviate the fear

of losing your valuable image data in the future as camera raw formats are dropped and no support

is available for them in new software applications

You can convert your camera raw files into DNG files by downloading the DNG converter from Adobe’s Web site (www.Adobe.com) It’s free and simple to use It takes a bit of time to run, so plan on walking away from your computer while it processes your files

Tip

Bridge also converts your raw files to DNG files while they are being imported from your camera or card

reader Choose Bridge as the method of importing these files and check Convert to DNG in the dialog n

There are two excellent reasons to convert your camera raw files into DNGs and one drawback

DNG is becoming a popular and accepted file format A few cameras out there even capture in DNG, including Leica, Samsung, Casio, and Hasselblad You can easily convert your camera raw files into DNG files using the converter and open it in several applications that support it The chance of it becoming obsolete is small, and its popularity precludes it from doing so without plenty of warning

No XMP files

Because DNG is Adobe’s native camera raw format, Camera Raw has the power to save the meta-data straight to the file, eliminating the need to add the XMP sidecar file This means less clutter and less chance of your settings getting lost in the shuffle

Those pesky proprietary vendors

The downside of DNG is the unwillingness of certain vendors to work and play well with others

Sony, Canon, and Nikon have been known to encrypt their camera raw formats so that some of the information is accessible only using their proprietary raw processing applications This means that you may not have access to all the possible information just by processing your files in Camera Raw If you were to convert an encrypted file into a DNG, it stands to reason that you would lose any encrypted information

Opening Images in Camera Raw

Opening camera raw files isn’t any different from opening any other type of file Find your file or files in Bridge and double-click them to open them Photoshop launches if it’s not already open, but Camera Raw also launches, allowing you to process your image before opening it in Photoshop for the more “traditional” editing process If you are just cleaning up an image, Camera Raw can do all the editing required for most photos

Note

Although you can open several files in Camera Raw at once, you need to do this all at the same time If you try

to open an additional file while Camera Raw is already launched with a file open, your new file won’t open

until you’ve exited the current instance of Camera Raw n

You also can open JPEG and TIFF files in Camera Raw This gives you a quick editor for adjusting color and light in these file types To open these files in Camera Raw, right-click the thumbnail in Bridge and select Open in Camera Raw You also can set the preferences in Camera Raw to auto-matically open when these files are opened in Photoshop You can learn more about how to do this

in the discussion of preferences later in this chapter

Note

When you use the Open in the Camera Raw option after right-clicking an image, Camera Raw opens in Bridge

The Camera Raw dialog box opens every time you open a camera raw file, even if it’s a file that you’ve already processed Don’t worry; the settings are just as you left them You can either read-just them or click Open Image to access Photoshop

Tip

You really don’t need to open Camera Raw every time you want to work with a raw image in Photoshop If

you’ve already processed your photo and like your settings, or you’re just satisfied with the way the photo

looks, press the Shift key as you double-click to open it, and it opens directly into Photoshop, bypassing

Camera Raw n

The Camera Raw Workspace and Workflow Options

Now that you understand the basics of how camera raw files work, it’s time to start editing them I start by introducing you to the Camera Raw workspace These are the main features of the Camera Raw workspace, as labeled in Figure 7.3

l Document Window: The Document window displays the document that is currently

selected in the filmstrip At the bottom, you see the Zoom Level drop-down menu From this menu, you can select a zoom percentage or the fit-to-screen option Next to the Zoom Level, the document name is displayed On the bottom right of the document window are arrows that let you toggle through the documents in the filmstrip

l Filmstrip: The filmstrip shows all the documents that are currently open in Camera Raw

You can select more than one by pressing the Shift or Ctrl (Ô) keys while you select, or by clicking the Select All option Select more than one file to make the same changes to all of them at once, such as setting the white balance on several photographs taken at the same time You probably want to select all the files you want opened in Photoshop before you close Camera Raw

l Camera Raw tools: These are the tools that help you make adjustments in Camera Raw

These tools do everything from setting the White Balance to correcting red eye

l Histogram: The Histogram is a very important feature of correctly setting the levels of

color and brightness values in your image Understanding the histogram helps you make better adjustments If you are unsure what the histogram represents and how to use it, please review Chapter 4

l Document Window: The Document window displays the document that is currently

selected in the filmstrip At the bottom, you see the Zoom Level drop-down menu From this menu, you can select a zoom percentage or the fit-to-screen option Next to the Zoom Level, the document name is displayed On the bottom right of the document window are arrows that let you toggle through the documents in the filmstrip

FIGURE 7.3

The workspace

Filmstrip Camera raw tools Histogram

Image adjustment tabs

Document window Image adjustment panel

l Filmstrip: The filmstrip shows all the documents that are currently open in Camera Raw

You can select more than one by pressing the Shift or Ctrl (Ô) keys while you select, or by clicking the Select All option Select more than one file to make the same changes to all of them at once, such as setting the white balance on several photographs taken at the same time You probably want to select all the files you want opened in Photoshop before you close Camera Raw

l Camera Raw tools: These are the tools that help you make adjustments in Camera Raw

These tools do everything from setting the White Balance to correcting red eye

l Histogram: The Histogram is a very important feature of correctly setting the levels of

color and brightness values in your image Understanding the histogram helps you make better adjustments If you are unsure what the histogram represents and how to use it,

l Image adjustment tabs: You can adjust a camera raw image in several ways, from color

settings to lens adjustments These are all represented in these tabs, which you learn more about in this and the next chapter

l Image adjustment panel: The Image adjustment panel changes based on the Image

adjustment tab that’s selected Each panel has several different adjustment settings that modify the way your image is interpreted

Workflow options

At the bottom of the Camera Raw workspace is a blue readout that is seemingly a modest bit of information On the contrary, it is really anything but unassuming Not only is it very important information, but it deals with important settings as well Clicking it, as shown in Figure 7.4, brings

up the Workflow Options dialog box, as shown in Figure 7.5

FIGURE 7.4

This is not only important information, but a link to the Workflow Options dialog box

Click to adjust Workflow options

Space

The first setting in the Workflow options is labeled Space, and it allows you to set the color space you want to work in You can choose from four color profiles and two grayscale profiles (if you have changed your raw file to grayscale), as shown in Figure 7.6 If you don’t see the profile you want, choose ProPhoto RGB and convert to your desired color space after opening your image in Photoshop

FIGURE 7.5

The Workflow Options dialog box

FIGURE 7.6

You can choose from four color profiles and two grayscale profiles in the Space drop-down menu

Choose a bit depth

The Depth setting allows you to choose to work with either 8 bits per channel or 16 bits per chan-nel Remember that the bits-per-channel setting determines how many tones your color channels can contain At 8 bits per channel, you have access to over 16 million colors, but 16 bits per chan-nel gives you trillions of colors The more colors you have access to, the easier and better your cor-rections in Camera Raw are It stands to reason that you want to work at 16 bits per channel as often as possible

So why is it that when you open Camera Raw for the first time, it is set at 8 bits per channel? Well, although technology is getting better all the time, there are still a limited number of file types and applications that can support 16-bit/channel images When you change the setting in Camera Raw

to 16 bits per channel and open your image in Photoshop, for instance, a few options—such as the Filter Gallery—are grayed out because they doesn’t support 16 bits per channel

The bottom line? You probably want to work with images that are set at 16 bits per channel to make any adjustments necessary in Camera Raw If you want to make changes to your image that

I’m pretty sure that Adobe sets your images to 8 bits per channel in the Camera Raw workspace as a default

because they don’t want you to pull your hair out over not having access to the Filter Gallery in Photoshop

later on When you set your images to 16 bits per channel, that setting stays set until you change it, so the next

photo you open in Camera Raw also is set to 16 bits per channel Remember this small detail so you won’t pull

your hair out over options you think you should have in the Photoshop workspace Take a deep breath, and

remember to convert your image back to 8 bits per channel n

Size

You can adjust the size of your image in Camera Raw by resampling it, just as you would in Photoshop This is one change in Camera Raw that is destructive Whenever you resample an image, you trust an algorithm to selectively add or destroy pixels to make your image larger or smaller Although resizing is often necessary, resizing an image over and over is unwise

You can make your image smaller by choosing a megapixel size with a minus sign next to it or make it larger by choosing a megapixel size with a plus sign next to it, as shown in Figure 7.7 You can return to the original size by choosing the megapixel size in the middle The one benefit of a camera raw file here is that returning to this original size restores your original settings (If you did this in Photoshop with a JPEG, it would just resample to the original size.)

Notice that these sizes don’t show your image dimensions The dimensions of your image are based not only on the number of pixels, but also on the resolution Changing the resolution does not change the number of pixels used in your image, however

FIGURE 7.7

Make your image smaller by selecting a megapixel setting with a minus sign or larger by selecting one with

a plus sign

Resolution

Setting the resolution of your photo changes the print size and quality It takes the available pixels and determines how many of them to pack into a linear inch Your computer screen displays at 72–96 ppi (pixels per inch) and many digital cameras shoot at that resolution, leaving you with a photo with huge dimensions When you take your photo in to be printed, the photo processor resizes your photos to the appropriate size and resolution, starting with the resolution A photo

printed at 72 dpi looks extremely pixilated, giving it a jagged look Increasing the resolution to at least 200 dpi gives you a much better result

Increasing the resolution automatically reduces the size of your image without resampling it

Instead of spreading 72 pixels per inch over 30 inches of photo, you can use the same pixels to pack 300 pixels per 7 inches of photo, giving you not only a better print resolution, but a more reasonable print size

Sharpen For/Amount

This allows you to apply output sharpening for Screen, Glossy paper, or Matte paper This option

is best used when you are planning to use your image straight from Camera Raw without opening

in Photoshop Sharpening an image is usually the last step you take before output because sharp-ening not only loses its effectiveness as other adjustments and filters are placed over it, but it is also one of the more destructive edits, making visible changes to the pixelization of your photo

After you have chosen an output to Sharpen for, you can choose to sharpen a high, standard, or low amount

Open in Photoshop as Smart Objects

Opening your raw image as a Smart Object makes it a little more complicated to work with in Photoshop, but it protects it from the Photoshop edits and allows you to open it back up in Camera Raw and make additional changes to it Smart Objects operate very differently from image files You can’t make adjustments directly to them—limiting changes to the layer adjustments The filters added

to a Smart Object also are added as separate sublayers After you’ve learned more about Smart Objects and how they work, the benefits and drawbacks of this option will be clearer to you

Cross-Ref

You learn more about Smart Object layers in Chapter 10 n

Now that you’ve seen the Workflow options, the blue readout at the bottom of Camera Raw should make sense to you You can glance down at any time to check your Workflow option settings and click to make changes if they are not set correctly for the image you are working on

Note

The Workflow Options settings stay the same as the last time you set them even if you are working on a new

image in Camera Raw Even if you resize an image, the next image is set to the same resize option This is

con-venient if you want your color workspace to always be set to ColorMatch RGB, but it’s something to be aware

of when working with different sizes of documents that you may or may not want sharpened n

Setting Preferences

The Camera Raw preferences can be accessed by clicking the Open Preferences icon in the tool