Sử dụng photoshop cs5 part 11 pps

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.. A Use the Workflow Options dialog to choose color

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.

Via the Workflow 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 file 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 The

Workflow Options dialog opens A

2 From the Space menu, choose a color profile

to be used for converting the raw file 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

(The 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 This value affects 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 predefined 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: The 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 The new workflow settings will be listed below the preview They 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 Workflow Options dialog (see page 86) Turn this feature

on only if it suits your normal workflow

A Use the Workflow 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

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).

AClick a tab icon to access the specialized options it has to offer.

Basic Detail Split Toning Effects

Tone Curve

Camera Calibration

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

When you open a photo into Camera Raw, by

default, it’s adjusted according to the built-in

pro-file for your camera model To assign a different

collection of settings to your file 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 file from either the initial

photo shoot or a prior Camera Raw session

When you first 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 specific 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 first 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

file into Camera Raw, the sliders are set to the

default settings for your camera model The first

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

first round of adjustments, we recommend using

the sliders in the order in which they’re listed The

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 The white areas

indicate where the three colors overlap

B The Camera Raw histogram charts the number of pixels

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.

B When a photo is opened into Camera Raw for the first 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 fit the photo in the preview

2. The white balance (color temperature) should

be adjusted first, because this setting affects 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 file

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 fine-tune the

tem-perature correction, move the Tint slider slightly

to the left to add green or to the right to add

magenta The listing on the White Balance menu

will change to Custom

A These are the As Shot settings for the photo

shown in B.

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 The histogram reflects 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 Workflow 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 The 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 affect 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 off the Clipping Warnings by pressing U,

then O

➤ To adjust the saturation of specific colors, see pages 74–75

A Activate the Clipping Warning buttons above the histogram (when a warning is on, it has a white border) This is the histogram for the original photo, which is shown in Aon 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

CORRECTING AN UNDEREXPOSED PHOTO

A The original photo is underexposed, as you can see by

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 effect 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) The 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!

* The 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.