Sử dụng photoshop cs5 part 11 pps

7 289 0
Sử dụng photoshop cs5 part 11 pps

Đang tải... (xem toàn văn)

Thông tin tài liệu

ptg Camera Raw 65 You can also straighten a photo before opening it into Photoshop. To straighten a crooked photo: 1. Choose the Straighten tool (A). 2. In the preview, drag along an edge in the photo that you want to align to the horizontal or ver- tical axis. B A crop marquee will display, aligned to the angle you drew. C When you open the image into Photoshop, that edge will be aligned with the document window. D ➤ To preview the crop results, press Enter/Return or click another tool. ➤ To redisplay a crop (or straighten) marquee after using another tool, choose the Crop (or Straighten) tool again. To remove it, press Esc. Cropping and straightening photos With the Crop tool, you can control which portion of a photo opens in Photoshop. You can readjust the crop marquee at any time, and it will remain available even after you click Save, Done, or Open. All the raw pixels are preserved. To crop a photo: 1. Open a photo into Camera Raw (see page 63). Choose the Crop tool (C). 2. Drag a marquee on the preview image. A To move the marquee, drag inside it; to resize it, drag a handle. Only the area within the marquee will import into Photoshop. 3. To preview the crop results, press Enter/Return or click another tool. D We opened the straightened image into Photoshop. C A marquee displays in Camera Raw. B With the Straighten tool, we are dragging along an edge that we want to align to the vertical or horizontal axis. A With the Crop tool, drag a marquee in the preview window. ptg 66 Chapter 4 Via the Workow Options dialog, you can change the color space, dimensions, bit depth, and resolu- tion of a photo before opening it into Photoshop — without altering the original digital le. Your choices will become the new default settings. To choose default workflow settings: 1. Open a photo into Camera Raw, then at the bottom of the dialog, click the underlined link that lists the color space, bit depth, etc. e Workflow Options dialog opens. A 2. From the Space menu, choose a color prole to be used for converting the raw le to RGB: Adobe RGB (1998), ColorMatch RGB, ProPhoto RGB, or sRGB IEC61966-2.1 (or “sRGB,” for short). In Chapter 1, you assigned Adobe RGB as the default color space for color manage- ment, so we suggest choosing it here, too. 3. From the Depth menu, choose a color depth of 8 Bits/Channel or 16 Bits/Channel (see page 19). If you have a large hard drive and a fast system with a lot of RAM, choose 16 Bits/ Channel. With the extra pixels, more of the original tonal levels in your photo will be preserved when it’s edited in Photoshop. 4. If you need to resize the image, from the Size menu, choose a preset size (in megapixels) that matches the proportions of the raw image. (e default size is the one without a minus sign – or plus sign +.) Resampling will occur if you choose a larger size than the original. Avoid choosing the largest size, to help prevent pixelization. (Experts disagree on whether it’s better to resample an image in Camera Raw or in Photoshop. Until a consensus is reached, you can decide for yourself.) Note: If a crop mar- quee is present, the Size menu will be labeled Crop Size, and it will list the current crop size. 5. Enter a Resolution. is value aects only the print output size. (For instance, a resolution of 240–300 ppi would be appropriate for an image that is 2000 x 3000 pixels or larger, for output to an inkjet printer or a commercial press.) 6. Optional: From the Sharpen For menu, choose None, Screen, Glossy Paper, or Matte Paper to apply predened output sharpening to your photo for the chosen medium. Also choose the desired amount of sharpening from the Amount menu (Standard is usually a good choice). Note: e sharpening values that are applied via this dialog aren’t listed anywhere. For greater control over capture sharpening, choose None from the Sharpen For menu here and use the sliders in the Detail tab instead (see page 76). 7. Click OK. e new workow settings will be listed below the preview. ey will be applied to the current photo and to photos that you sub- sequently open into Camera Raw. ➤ To have future photos open from Camera Raw into Photoshop as a Smart Object layer when you click Open Object, check Open in Photoshop as Smart Objects in the Workow Options dialog (see page 86). Turn this feature on only if it suits your normal workow. A Use the Workow Options dialog to choose color space, bit depth, size (dimensions), and resolution settings for the current photo, and to establish the default settings for future photos. Choosing default workflow settings ptg Camera Raw 67 Detail tab: Apply capture sharpening and reduce noise (see pages 76–77). HSL/Grayscale tab: Adjust individual colors (see pages 74–75). B In Camera Raw, we perform most of our correction work in the four tabs that are shown above. exposure (see pages 72–73). Tone Curve tab: Fine-tune the Basic tab: Adjust the white balance and exposure (see pages 68–71). A Click a tab icon to access the specialized options it has to oer. Basic Detail Split Toning Eects Tone Curve Camera Calibration HSL/Grayscale Presets Snapshots Lens Corrections Using the Camera Raw tabs To restore the default settings to sliders in the Camera Raw tabs: Double-click a slider to restore the default value to just that slider. Shift-double-click a slider to restore the Auto setting to just that slider. Click Default in the Basic or HSL/Grayscale tab to reset the sliders in just the current tab to their default values (that is, to remove any custom settings). Choose Camera Raw Defaults from the Camera Raw Settings menu to reset all the sliders in all the tabs to the default settings for the camera model that was used to take the photo. Learn about the Camera Raw Settings menu on the next page. Hold down Alt/Option and click Reset (Cancel becomes Reset) to restore the dialog settings that were in place when the dialog was opened. TOGGLING THE PREVIEW Check Preview (P) at the top of the Camera Raw dialog to preview changes made in all the tabs; or uncheck Preview to view the result of changes made in all the tabs except the current one, so you will be able to evaluate the most recent changes. ptg 68 Chapter 4 When you open a photo into Camera Raw, by default, it’s adjusted according to the built-in pro- le for your camera model. To assign a dierent collection of settings to your le or to restore the original settings, see the choices listed below. To restore settings via the Camera Raw Settings menu: Choose one of these settings from the Camera Raw Settings menu: A Image Settings to restore the settings that were attached to the le from either the initial photo shoot or a prior Camera Raw session. When you rst open a photo, these settings will match the Camera Raw Defaults settings. Camera Raw Defaults to remove any custom settings and reapply the default settings for your camera model, your specic camera, or the ISO setting that was used to take the photo. Previous Conversion to apply the settings from the prior image that was adjusted in Camera Raw. Custom Settings to reapply any custom set- tings that were chosen since the Camera Raw dialog was opened. If a user-saved preset is currently applied to the photo, that preset will be listed (see page 83). Using the Basic tab When you rst open a JPEG photo into Camera Raw, all the sliders in the Basic tab are reset to zero automatically, whereas when you open a raw le into Camera Raw, the sliders are set to the default settings for your camera model. e rst step is to use the Basic tab to make any needed corrections to the white balance (see the sidebar at right), exposure, contrast, and saturation. For this rst round of adjustments, we recommend using the sliders in the order in which they’re listed. e good news is that they cause far less destruction than the adjustment controls in Photoshop do. As you perform adjustments in the Basic tab, keep your eye on the histogram (in the dialog) so you can monitor how tonal values are being redis- tributed in the photo. B Red, green, and blue pixels are superimposed upon one another at each tonal level in the graph, with shadow pixels on the left and highlight pixels on the right. e white areas indicate where the three colors overlap. B  e C a m e r a R a w h i s t o g r a m c h a r t s t h e n u m b e r o f p i x e l s at each tonal level in your photo. WHITE BALANCE, IN PHOTOGRAPHY The color temperature of the lighting in which a photo is shot, whether that lighting is natural or artifi cial, affects the relative amounts of red, green, and blue that a digital camera records. The camera attempts to balance those three colors to produce an accurate white, and then uses the balanced white to make other colors in the photo more accurate. You can refi ne the white balance of a photo in Camera Raw. Note: In the Camera Raw dialog, you could adjust the white balance that was produced by your camera with the White Balance tool (you click a gray- ish white area in a photo that contains some detail, to be used by the tool as a sample area). However, deciding which area to click can be tricky, so we recommend using the Temperature and Tint sliders instead, as described on the next page. A Use the Camera Raw Settings menu to reapply the default settings or the previous settings. ptg Camera Raw 69 B When a photo is opened into Camera Raw for the rst time, the setting on the White Balance menu in the Basic tab is As Shot. C A lower Temperature value makes the photo cooler. Now there is a noticeable blue cast in the metal and grass. D A higher Temperature value makes the photo warmer (note the metal and grass again). To apply white balance adjustments using the Basic tab: 1. Click the Basic tab, A–B and double-click the Hand tool to t the photo in the preview. 2. e white balance (color temperature) should be adjusted rst, because this setting aects the overall photo. Do either of the following: From the White Balance menu, choose a preset that best describes the lighting conditions in which the photo was taken (this is for a raw le only). Choose As Shot at any time to restore the original camera settings. To correct the color temperature manually, lower the Temperature value to add blue and make the image cooler, C or raise it to add yellow and make the image warmer. D To ne-tune the tem- perature correction, move the Tint slider slightly to the left to add green or to the right to add magenta. e listing on the White Balance menu will change to Custom. A  e s e a r e t h e A s S h o t s e t t i n g s f o r t h e p h o t o shown in B . ptg 70 Chapter 4 To apply tonal adjustments using the Basic tab: 1. When the Camera Raw dialog opens, the tonal sliders in the Basic tab — Exposure, Recovery, Fill Light, Blacks, Brightness, and Contrast — are set to their default values, and the word “Default” is dimmed. For the heck of it, click Auto to see which settings Camera Raw deems appropriate for your photo. Next, for better results, click Default to restore the default values, and follow the remaining steps. 2. e histogram reects the current Camera Raw settings and redraws as you change them. Study the graph to see if any highlight or shadow pixels are being pushed to the edge (are being clipped). Clipping occurs if the tonal range of a scene is wider than the range the camera can capture. Your goal will be to bring the pixels into the range of your chosen RGB color space, in order to minimize clipping. (In our setup, we have chosen the Adobe RGB color space for our camera; we have also chosen it for Camera Raw via the Workow Options dialog.) 3. To minimize the clipping of highlight and shadow pixels, do the following: In the top left corner of the histogram, click the Shadow Clipping Warning button (U) to display a representation of shadow clipping as blue in the preview. In the top right corner, click the Highlight Clipping Warning button (O) to display highlight clipping as red A (and A , next page). Monitor this display of clipping as you apply corrections to your photo. To bring out details in the highlights, use the Exposure and Recovery sliders as a duo. For an overexposed photo, move the Exposure slider to the left and the Recovery slider far to the right until only a trace remains of the red highlight warning color (you can use either the sliders or the scrubby sliders) ( B , next page). To bring out shadow details, use the Blacks and Fill Light sliders as a duo. For an underexposed photo, move the Fill Light slider slightly to the right. For a raw photo, also move the Blacks slider to the left until only a trace remains of the blue shadow warning color ( C , next page). To minimize clipping another way, Alt-drag/ Option-drag the Exposure and/or Recovery sliders and release the mouse when small amounts of white (representing all three color channels) display in the black preview. Alt- drag/ Option-drag the Blacks slider and release the mouse when small amounts of color or black display in the white preview. e color areas represent clipping in those channels. 4. Optional: Adjust the Brightness to enhance details in the midtones, and the Contrast to increase or decrease contrast ( D , next page). Note: For an even better way to adjust the midtones in a photo, see page 72. Finally, you can use the Clarity slider in the Basic tab to adjust the edge contrast and the Vibrance slider to adjust the color saturation. Note: Although both the Vibrance and Saturation sliders aect color saturation, the latter can cause oversatura- tion and highlight clipping, whereas the former is much less likely to (move the Saturation slider to the far right, and you’ll see what we mean). Even at a moderately high setting, Vibrance doesn’t cause oversaturation of skin tones. To adjust edge contrast and color saturation using the Basic tab: 1. To add depth by adjusting the edge contrast in the midtones, increase the Clarity value, or reduce this value if you want to deliberately soften a photo, such as a portrait or landscape. 2. Adjust the Vibrance value to increase or reduce the color saturation ( E , next page). 3. Turn o the Clipping Warnings by pressing U, then O. ➤ To adjust the saturation of specic colors, see pages 74–75. A Activate the Clipping Warning buttons above the histogram (when a warning is on, it has a white border). is is the histogram for the original photo, which is shown in A on the next page. Most of the pixels are clustered at the left edge of the graph, which indicates that the image is underexposed. Shadow Clipping Warning button Highlight Clipping Warning button ptg Camera Raw 71 CORRECTING AN UNDEREXPOSED PHOTO A  e o r i g i n a l p h o t o i s u n d e r e x p o s e d , a s y o u c a n s e e b y the blue and red clipping warning colors in the preview. B We raised the Exposure value in the Basic tab to lighten and recover details in the highlights and midtones.* We also raised the Recovery value to recover some details in the bright, metallic highlights, but left some clipping because we want some of those highlights to remain pure white, with no details. D We increased the Brightness value to recover more details in the midtones; we also increased the Contrast value, which had the eect of intensifying the shadows. C We used the Fill Light and Blacks sliders to recover details in the shadows (the lower front area of the car and in the grass). e blue and red clipping warning areas have now been minimized. E Finally, we increased the Clarity value to enhance the edge contrast and increased the Vibrance value to boost the color saturation. Now this classic MG really shines! * e settings on this page were applied to a raw photo. If you downloaded and are working on the JPEG version of this photo, choose a Recovery value of 90, a Fill Light value of 20, a Blacks value of 0, and a Brightness value of +28. . within the marquee will import into Photoshop. 3. To preview the crop results, press Enter/Return or click another tool. D We opened the straightened image into Photoshop. C A marquee displays. Raw. ➤ To have future photos open from Camera Raw into Photoshop as a Smart Object layer when you click Open Object, check Open in Photoshop as Smart Objects in the Workow Options dialog. and straightening photos With the Crop tool, you can control which portion of a photo opens in Photoshop. You can readjust the crop marquee at any time, and it will remain available even after

Ngày đăng: 02/07/2014, 06:20

Tài liệu cùng người dùng

Tài liệu liên quan