Photoshop CS4 Studio Techniques- P9 pdf

A grainy image will start to look unusual when you get an Amount setting anywhere near 100–150 Figure 6.39; you might even need to bring the Amount setting down to near 20 before the gr

The procedure we’ve just discussed is the usual approach

to sharpening most images, but sometimes you’ll need to

go a different route The Radius setting can have a cal effect on sharpening You’ll need to achieve a bal-ance between Amount and Radius High Amount settings (about 90–250) will require low Radius settings (.5–1.5), and low Amount settings (10–30) will require higher Radius settings (5–20) High Amount settings work for most images, and that’s why we took the initial approach just mentioned

radi-If you have a grainy image and you want to maintain but

not exaggerate the grain (Figure 6.38), you’ll need to take

a slightly different approach A grainy image will start to look unusual when you get an Amount setting anywhere

near 100–150 (Figure 6.39); you might even need to bring

the Amount setting down to near 20 before the grain stops being exaggerated too much At that point, you’ll barely

be able to tell that the image has been sharpened (Figure

6.40); to compensate, you’ll need to get the Radius setting

up until the image starts to look sharp (Figure 6.41) On

most images, you’ll be able to use much higher Amount settings without causing grain problems In that case, you might end up with an Amount setting around 120, and then you’ll need to experiment with the Radius setting to see what looks best (probably between 5 and 1.5)

Figure 6.37 Adjust the Amount

set-ting until the image looks realistically

sharp.

II: Production Essentials

Figure 6.40 With the Amount setting at 20,

the grain is less, but the image doesn’t look

sharp.

Figure 6.39 With the Amount setting at 150, the grain is becoming too obvious (Look very closely to see the difference between this figure and Figure 6.38.)

Figure 6.41 With the Amount setting at 20

or so and the Radius up to 1.5, the image becomes sharp.

Figure 6.38 An old grainy image (©2008

Dan Ablan.)

Using Smart Sharpen

The Smart Sharpen fi lter (Figure 6.42) expands on the

concepts of the Unsharp Mask fi lter to deliver a more sophisticated method for sharpening images However, there are many instances where you might prefer the Unsharp Mask fi lter, for reasons explained in a moment

The Amount and Radius settings in the Smart Sharpen

fi lter work just like the ones in the Unsharp Mask fi lter

In fact, the results are identical when the Remove pop-up

menu is set to Gaussian Blur (Figure 6.43) Setting the

Remove menu to Lens Blur causes the halos that come along with sharpening to be less pronounced, which allows you to get away with higher Amount and Radius settingsbefore the sharpening halos become overly obvious

(Figure 6.44) You can use this setting whenever quality

is more important than speed (which is often the case in normal workfl ow) You can also set the Remove pop-up menu to Motion Blur and then experiment with the Angle setting to reduce the blurring effect of lens shake It’s not

a miracle worker, though, so it will only be effective when the camera shake was almost unnoticeable

Turning on the More Accurate check box causes the image to be sharpened in two passes (just like applying the Unsharp Mask fi lter twice) This can make edges much

more prominent (Figure 6.45), but you have to be very

Figure 6.42 The Smart Sharpen

dialog, with the Remove option set to

Gaussian Blur (©2008 Dan Ablan.)

Figure 6.43 Gaussian Blur setting.

Figure 6.44 Lens Blur setting.

Figure 6.45 Lens Blur setting with

More Accurate check box turned on.

II: Production Essentials

careful because it also has a tendency to over-exaggerate

grain and noise in images

You might fi nd that you’ll use the Unsharp Mask fi lter for

images that contain fi ne texture, such as skin or brick,

because the Smart Sharpen fi lter does not offer the

Threshold setting that allows you to limit the sharpening

effect to areas of more pronounced detail

Advanced Mode

The Smart Sharpen fi lter also offers an Advanced mode,

which allows you to control the strength of the sharpening

that will be applied to the shadows and highlights of the

image (Figure 6.46) This feature can be useful in instances

when a considerable amount of noise is present in the dark

portion of an image The Fade Amount setting determines

the strength of the sharpening effect; the Tonal Width

set-ting determines the brightness range that will be affected

by the sharpening, and the Radius setting determines how

the sharpening effect will blend into the surrounding

image A good way to work is to start with Fade Amount

at 100% and Radius at 3 so that you can see the full

effect of the sharpening Then adjust Tonal Width until

the sharpening no longer affects any overly noisy areas

Finally, adjust the Fade Amount slider to see just how much

sharpening you can use without exaggerating the noise in

the image

Figure 6.46 Advanced options.

More Art Than Science

The process of sharpening takes a good bit of practice before you start feeling confi dent Everyone has a different idea of how sharp an image should look, and most output devices aren’t capable of reproducing the amount of detail you see onscreen Even if you sharpen the image so that it looks great onscreen, when you print the image it might still look rather soft Following are some general thoughts

on how to approach sharpening for different types of output:

Web/multimedia: When the fi nal image will be displayed onscreen, you can completely trust your screen when sharpening the image Most of the time you’ll end up with Radius settings between 5 and 1 and Amount settings below 100% Just be aware that sharpening increases the fi le size of JPEG fi le format

images (Figures 6.47 to 6.49) If you’re planning to save

the image as a JPEG fi le, use the absolute minimum amount of sharpening that makes the image look crisp

Figure 6.47 The original unsharpened

image (©2008 Dan Ablan.)

Figure 6.48 The image from Figure 6.47, sharpened with settings of Amount 70, Tonal Width 5, and Radius 4.

Figure 6.49 The image from Figure 6.47, sharpened with settings of Amount 175, Tonal Width 7, and Radius 4.

Photographic output devices: These devices include

fi lm recorders, LightJets, and other gadgets that use

II: Production Essentials

photographic fi lm or paper to reproduce an image

They can reproduce the majority of the detail you see

onscreen With these devices you have to be very

care-ful to make sure that the Radius setting is quite low (.25

to 7 for most images), so that the halos that come from

sharpening aren’t obvious on the end result

Desktop printer: This includes inkjet and laser printers

Experiment with an image that’s representative of the

type of image you use the most

Commercial printing press: Start by sharpening images

until they look very sharp onscreen, and then analyze

the printed result when you get a job back from the

printing company If the printed result doesn’t look

too sharp, slowly ratchet up the Amount and Radius

settings on subsequent images until the printed images

look very sharp, but still natural Compare the printed

result to the original digital fi le each time, viewing the

image at 100% magnifi cation As you work on more

and more jobs, you’ll start to get a feeling for how

much you need to overdo the sharpening onscreen to

get a nice sharp end result Different types of

print-ing produce differprint-ing amounts of detail (Newspaper

images need to be sharpened much more than images

that will be printed in a glossy brochure.)

If thinking about all the different settings needed for

different output devices drives you crazy, consider adding

a commercial plug-in fi lter to Photoshop Nik Software

(www.niksoftware.com) makes a set of plug-in fi lters known

as Sharpener Pro (Figure 6.50), which takes a lot of the

guesswork out of sharpening images The package comes

with separate fi lters for different types of output

(includ-ing inkjet, color laser, offset print(includ-ing, and Internet) and

compensates for different viewing distances and image

sizes, all without having to think about Amount, Radius,

and Threshold settings The results might just be a little bit

too aggressive; if so, choose Edit > Fade immediately after

applying the fi lter, and lower the Opacity setting a bit It

might be a personal preference as to what you consider to

be a naturally sharp result, so the fi nal Opacity setting will

be unique to you

Figure 6.50 Nik Sharpener Pro takes a lot of the guesswork out of sharpening.

Do you plan to use an image for more than one purpose? Ideally, you should create a unique version of the image for each use Choose Image > Duplicate to create an exact copy of an image Then choose Image > Image Size

(Figure 6.51) to set the proper size and resolution for the

output device for which this particular image is destined Finally, sharpen the image based on your experience with that particular device As you repeat the process for other devices, always go back to the full-sized master image before repeating the steps

If you simply can’t deal with one image for each device, work with a single image and do the following: Set the

resolution to what’s needed for your most demanding

output device (the one that needs the highest-resolution

image), and sharpen for the device that looks closest to your

screen (the one that needs the least radical sharpening) Then use that one image for all output devices That’s kind of like buying one shoe size for an entire basketball team As long as it’s large enough for the biggest person, everyone should be able to fi t in it, but it won’t be ideal for everyone

Tricks of the Trade

Now that we’ve talked about the general process of ening an image, let’s start to explore some more advanced ideas that will allow you to get more control over your sharpening

sharp-Sharpen Luminosity

If you look closely at a color image after it’s sharpened, you might notice bright-colored halos around objects that were not all that colorful in the original photo (In

Figure 6.52, notice the green fringe around the blue shirt.) To prevent that type of unwanted sharpening artifact, choose Edit > Fade Unsharp Mask immediately after sharpening an image When the Fade dialog appears, set the Mode pop-up menu to Luminosity and then click

OK (Figure 6.53) That will force the sharpening you just

applied to affect only the brightness of the image and will prevent it from shifting or intensifying the colors in the

Figure 6.51 Use the Image Size dialog

to specify the size and resolution of

the image.

II: Production Essentials

image (Figure 6.54) If you read a lot of books and

maga-zine articles about Photoshop, you might discover that

many people attempt to get the same result by converting

their image to LAB mode and then sharpening the image

The only problem with that approach is that any time you

change the mode of an image, you lose a little quality So

try to switch modes only when you have a good reason to

do so Fading after applying the Unsharp Mask fi lter gives

you the same benefi ts as converting to LAB mode, so try to

leave the image in its original mode when sharpening

Figure 6.52 You can get colored halos around objects in an image when

sharpening.

Figure 6.53 Use Fade directly after using the Unsharp Mask filter to have the sharpening affect only the brightness in the image.

Figure 6.54 A closeup view of the sharpened image, now without fringing.

Sharpen the Black Channel

If an image is destined for CMYK mode, be sure to make

an extra sharpening pass on the black channel Just open

the Channels panel (Window > Channels), click the Black

channel, and sharpen away Because black ink is mainly

used in the darker areas of the image, you can get away

with some rather aggressive settings (Try these: Amount =

350, Radius = 1, Threshold = 2.) Perform this sharpening

pass after you’ve already sharpened the full-color image

(Figures 6.55 to 6.57).

Remember, in order to sharpen the black channel, the image needs to

be in CMYK mode Choose Image >

Mode > CMYK Color.

Figure 6.55 The original image, unsharpened (©2008 Dan Ablan.)

Figure 6.56 Unsharp Mask filter applied to the RGB channels.

Figure 6.57 Sharpening added to just the black channel.

II: Production Essentials

Sharpen Channels Separately

Certain images don’t look good after being sharpened For

instance, when you sharpen a face, it sometimes seems to

just fall apart, making the person look years older Another

example would be scanned images in which color noise is

exaggerated In those cases, consider clicking through the

channels that appear in the Channels panel and

sharpen-ing only the channels that would help the image For light

skin, that would be the channel that’s the lightest—red

in RGB mode or cyan in CMYK mode (Figures 6.58 to

6.60) For noisy images, avoid sharpening the channel that

contains the most noise—usually blue in RGB mode or

yellow in CMYK mode You shouldn’t use this technique

every time you want to sharpen images, but it’s something

to think about when sharpening a full-color image is doing

more harm than good

Figure 6.58 Red channel (©2008

Dan Ablan.)

Figure 6.59 Green channel. Figure 6.60 Blue channel.

Control Highlights and Shadows Separately

When you sharpen an image, Photoshop adds a dark halo

on one side of an edge and a bright halo on the opposite

side of the edge When you’re working with dark

back-grounds, such as a deep blue sky, the bright halos can

be rather easy to see (Figure 6.61) Try controlling the

bright and dark halos separately so that you can minimize

the bright halo while maintaining the dark one You can

accomplish that goal by making two duplicates of the layer you want to sharpen Click each of the duplicate layers and set the Blending Mode pop-up menu at the top of the Layers panel to Lighten for one and Darken for the

other (Figure 6.62) Now you can sharpen the two layers

separately The setting you apply to the layer that is set to Lighten will control the bright halos; the setting on the

layer set to Darken will control the dark halo (Figure 6.63).

Figure 6.61 The bright halos in this

image are getting obvious.

Figure 6.62 Duplicate the layer twice;

set one layer to Lighten mode and the other to Darken mode.

Figure 6.63 When you separate the dark and bright halos, you have more control over them.

The Next Step

If you felt like you were drowning in details in this chapter, try a few of the techniques; then come back and read it again, and things will start to gel It may take you a while

to become truly comfortable with sharpening images, but it’s well worth the time because you can transform fl at and lifeless images into ones that are lively and ready to pop off the page Now, here’s one more very important piece

of sharpening advice before we head to the next chapter: Oversharpened images never look good, so if you’re ever unsure of how much sharpening to apply, err on the side

of conservatism

Chapter 7: Setting Up Images for Final Output 237

Grayscale, Color, and Print

III

7 Setting Up Images for

Final Output

it’s blue Those of us who aren’t artists must color things the way they really are or people might think we’re stupid.

This chapter will guide you through understanding the color and grayscale values within your imagery You’ll see the difference between Levels and Curves, while also learning that grayscale is more than just a desaturation To begin, we’ll discuss some of the more obvious variables in the image-editing process: brightness and contrast

Brightness and Contrast

Years ago, Photoshop’s Brightness/Contrast dialog used

to adjust the entire tonal range of an image by equal amounts, which made it diffi cult to adjust one part of the image—say, the shadows—without destroying another part

of the image, such as the highlights However, Adobe has reengineered the Brightness/Contrast dialog with recent updates, and turned it into a very useful, very powerful tonal adjustment tool

To fi nd the Brightness/Contrast adjustment, choose Image > Adjustments > Brightness/Contrast The dialog

is very straightforward (Figure 7.1) By sliding the

Bright-ness slider back and forth, you can make the overall image brighter or darker In general, the Brightness slider protects

The techniques described in this

chapter are used by the high-paid

color maestros who are responsible

for all of those ever-so-perfect

glossy magazine ads It will take

you a while to really get the hang

of these techniques, but once you

do, it should take you just minutes

to correct most images.

Figure 7.1 The Brightness/Contrast

dialog.