HOW TO USE Adobe® Photoshop® CS2 [Electronic resources] نسخه متنی

Task 7 How to Work with Camera Raw Images

Camera raw images are 16-bit image files saved from professional and semiprofessional digital cameras. When you open one of these raw images, Photoshop launches a separate window that applies tone and sharpness corrections to the raw data as the file is opened, allowing you to save the result as a separate file. This capability enables you to explore and push the limits of the extended 16-bit file depth while preserving the original data values. Note that the controls for raw images are extensive. I won't attempt to explain all of them, but the steps that follow cover the majority of standard imaging corrections.

1. Open File

Click the Go to Bridge icon in the Options bar to launch Bridge. Navigate to the desired file and double-click its thumbnail to open it. If the file is a camera raw file, Photoshop automatically launches the Camera Raw window.

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2. Adjust Exposure

Adjust the Exposure slider to lighten or darken the primary tonal range. At the top of the Raw Plug-in dialog box are check box options for Shadows and Highlights that you can toggle on or off to highlight clipping in these areas. Avoid clipping tonal areas in most cases because doing so results in a loss of detail.

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3. Adjust the Shadows

Increase the Shadows slider to deepen the shadows in the image (note that too much darkening can cause a loss of shadow detail). Enable the Shadows clipping option at the top of the dialog box to highlight tonal areas within each channel that would be lost.

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4. Adjust the Remaining Exposure Controls

Modify the Brightness, Contrast, and Saturation sliders to complete the tonal modifications. If enabled, the Shadow and Highlights check box options highlight any clipped areas.

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5. Adjust Sharpness

Click the Detail tab and adjust the Sharpness slider as needed. Be sure to select 100% from the Zoom Level menu at the bottom of the window to see the actual sharpening results.

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6. Adjust for Chromatic Aberration

Chromatic aberration is a misalignment of color channels that is sometimes visible at the edges of digital images. It appears as colored fringing that corresponds to either a red/cyan or blue/yellow polarity (that is, the fringe will be red on one side of the image and cyan on the other). Click the Lens tab and adjust the Chromatic Aberration R/C or Chromatic Aberration B/Y slider as needed.

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