Photoshop-Viz: Adjustment Layers in photoshop

Adjustment Layers

“Insanity—a perfectly rational adjustment to
an insane world.”
—R.D. Laing

Adjustment Layers

Imagine being able to adjust the look of an original
image without damaging or otherwise altering it. You can
go back at any time and reﬁne the adjustment—or remove
it altogether and start over with another adjustment.
Photoshop’s adjustment layers make all of this possible.
Combine adjustment layers with layer masks and blending
modes, and you’ve got an unbeatable mixture that pro-
vides the cornerstone for working nondestructively. CS4
has made adjustment layers even easier to set up than in
previous versions, thanks to the new Adjustments panel.
Adjustment layers can be used on the majority of images
you’ll handle. Consider this feature to be the key to work-
ing quickly, having absolute ﬂexibility, and obtaining the
highest possible quality.

Adjusting Methods

You can adjust a layer directly, or apply the adjustment
through an adjustment layer. Let’s look at the fundamental
differences between these approaches.

Making Direct Adjustments
When you adjust a selected layer by choosing Image >
Adjustments and making a selection from the submenu
(Figure 5.1), the adjustment affects only the active layer,
and the original state of the layer will be changed perma-
nently once you save and close the document. Think of this

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Figure 5.1 Choosing Image > Adjust-
ments applies an adjustment directly
to the active layer.

approach as your “in a hurry and not too worried about
changing it later” adjustment. Direct adjustments have two
major downsides:

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 If you need to isolate an area, you have to create a selec-
tion before applying the adjustment or use the History
Brush after the adjustment is applied—but nothing can

be done after the image has been saved and closed.
 To alter the effects of a blending mode (more on
this topic later in the chapter), you have to choose
Edit > Fade (Figure 5.2) immediately after applying an
adjustment—you cannot make such changes after using
any other tools.
There’s really nothing wrong with adjusting an image
directly, as long as you know what the image needs, don’t
want to do a lot of experimenting, and don’t make any
mistakes. If you choose to make direct adjustments, save
your working image as a different ﬁle, preserving the
original image. An image will not suffer in any way what-
soever by being adjusted directly. Having said that, how-
ever, we must move along on our mission to convince you
that adjustment layers are by far the most efﬁcient and
nondestructive way to adjust images.

Adding Adjustment Layers
To create an adjustment layer, you can use either of two
methods:
 Choose Layer > New Adjustment Layer and then
select any of the available adjustments (Levels, Curves,
Hue/Saturation, and so on).
 Click the Adjustment Layer icon at the bottom of
the Layers panel and choose an adjustment from the
pop-up menu (Figure 5.3).

Figure 5.2 Choosing Edit > Fade
immediately after adjusting a layer
allows you to change the opacity and
blending mode used to apply the
adjustment.

Figure 5.3 The Adjustment Layer
pop-up menu at the bottom of the
Layers panel.

Once you’ve selected your adjustment, it will appear as a
separate layer in the Layers panel (Figure 5.4). Think of it
as if you’re standing at the top of the Layers panel looking
down; the adjustment layers are like ﬁlters that you attach
to the lens of a camera. Anything you see through that
adjustment layer (ﬁlter) will be affected by the adjustment,
whereas layers that appear above the adjustment layer will
not be affected (Figures 5.5 to 5.7).
Figure 5.4 The top layer here is an
adjustment layer.

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Figure 5.5 The original image is made
from a total of four layers.

Figure 5.6 Adding an adjustment
layer. (See the next section for an
explanation of those icons on the

Figure 5.7 Only the layers under the
adjustment layers are affected by
the adjustment.

adjustment layer.)

The adjustment is in its own layer, isolated from the
underlying image, allowing you to retain the unmodiﬁed
original. At any time, you can simply turn off the eyeball

You can have only one adjustment
per layer. If you want to combine
adjustments, change the blending
modes between them. Alternatively,
you can simply open the Layer menu
and choose Merge Visible for the
selected adjustment layers.

If setting the Opacity to 100%
doesn’t produce a strong enough
effect, try duplicating the adjust-
ment layer, which will often
double the effect of the adjustment
(depending on the type of adjust-
ment being applied).

icon on the adjustment layer, and the image will return to
its unmodiﬁed state. In Figure 5.7, we’ve tinted the image
by emphasizing the green color channel on the Curves
adjustment layer.
To lessen the effect of the adjustment layer, lower its Opacity
setting at the top of the Layers panel. Since the adjustment
hasn’t been applied to the image permanently, you can also
double-click the adjustment layer icon at the left side of the
adjustment layer to modify the adjustment settings.
Many other features can be added to the adjustment layer
to limit which layers are affected by the adjustment, con-
trol which areas of the document are affected, or change
how the adjustment interacts with the underlying layers.
The rest of this chapter covers those topics.
Adjustment layers are much more useful than direct adjust-
ments because the image can be saved (in formats that
support layers) and then reopened in the future for more

editing of the adjustment(s). Adjustments made through

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adjustment layers only become permanent when you
merge them into the underlying image or save the image
in a ﬁle format that doesn’t support layers.

Adjustment Layer Features

Let’s take a look at the accessories that are attached to an
adjustment layer (Figure 5.8). After an adjustment layer

is added to the Layers panel, the eyeball icon determines
whether the adjustment layer is currently affecting the
appearance of the image. To its right is another icon that
represents the type of adjustment being applied. Simply
double-click that adjustment layer icon to edit that adjust-
ment. To the right of the adjustment layer icon is a link
symbol, which really doesn’t apply to adjustment layers.
And to the right of that is a layer mask that allows you
to limit where the adjustment will affect the underlying
image. Photoshop automatically names each new adjust-
ment layer with the selected adjustment, such as Curves.
However, you can right-click the added layer, choose Layer
Properties, and rename it to something more speciﬁc.
Conversely, you can double-click the default layer name,
which makes that name editable directly in the layer itself.

The eyeball icon controls whether the
adjustment layer is visible or hidden.
Double-click the adjustment layer
icon to edit the adjustment.

A generic Adjustment Layer icon
(which looks like a half-black and
half-white circle) replaces the
thumbnails in the Layers panel
when the layers are too small
to allow room for the full-sized
versions. This can happen when
the document is much wider than
it is tall. You can also right-click
any layer icon and choose a larger
thumbnail size from the contextual
menu to see the specific icon for a
given layer adjustment, regardless
of the document’s orientation. You’ll
always see the generic adjustment
layer icon when the No Thumbnails
setting is selected.

The link symbol
doesn’t affect
adjustment layers.

The layer mask limits
where the adjustment
affects the image.

Figure 5.8 An adjustment layer looks like this
in the Layers panel.

When you add an adjustment layer in Photoshop CS4,

you can control it through the new Adjustments panel
(Figure 5.9). The Adjustments panel is a default panel in
the Essentials workspace. This panel allows you to modify

Figure 5.9 You can control an
adjustment layer with the
Adjustments panel.

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the adjustment settings being applied to the image; for
instance, if you have selected a Curves adjustment layer,
the Adjustments panel displays a smaller representation
of the Curves dialog that you get by choosing Image >
Adjustments.
With the Adjustments panel open (Figure 5.10), you can
choose any one of the adjustment options. Clicking one of
the icons adds that adjustment on an adjustment layer in
the Layers panel (Figure 5.11).

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Figure 5.10 Add any of a multitude
of adjustments with the Adjustments
panel. (Hover your mouse pointer over
the icons to see what each one does.)

Figure 5.11 Here we’ve added a
Hue/Saturation adjustment.

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Stacking Order
When you have more than one adjustment layer on an
image, the stacking order of the layers determines the
order in which the adjustments are applied. Adjustment
layers are applied from bottom to top, with the low-
est adjustment applied ﬁrst. You should always have the
topmost adjustment layer active when creating a new
adjustment layer, because new adjustment layers are always
added directly above whichever layer is active. Try to main-
tain the original stacking order, always adding new adjust-
ments to the top of the stack—adding an adjustment layer
between two others, or changing the stacking order of the
layers, can cause unpredictable changes to the overall look
of an image.

Before-and-After Views
If your document contains multiple adjustment layers, and
you want to view the original, unadjusted image, you’ll
have to hide all the adjustment layers by clicking their eye-
ball icons. To see the result of your adjustments, make the
adjustment layers visible by clicking the eyeball icons again.
All that eyeball clicking makes it difﬁcult to get a quick
before-and-after view of an image. To solve this problem,
hold down Option/Alt and click the eyeball icon for the
Background layer (or whichever layer contains the origi-
nal image). That action hides all the layers except the one
you’ve clicked. Just repeat the process to toggle all the hid-
den layers back into view.

Copying Adjustment Layers to Other Documents
It’s rather common for more than one photograph to
needs the same type of adjustment; a set of photos might
have similar subject matter and similar lighting, for
example. When that’s the case, you can adjust one of the
documents using adjustment layers and then drag those
adjustment layers on top of the second document (Figures
5.12 and 5.13). Select as many adjustment layers as needed
and drag from either the main document window or
the Layers panel. Just be aware that those layers will be
deposited above whichever layer is active in the destination

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document, which can cause some unexpected results if the
destination document already contains adjustment layers
and the topmost layer is not active.

Figure 5.12 The image on the right has multiple adjust-
ment layers.

Figure 5.13 Dragging the adjustment layers from the
image on the right to the one on the left instantly applies

those values to the new image.

Now that you have an idea of how adjustment layers oper-
ate, let’s explore a simple type of adjustment so you’ll
have something to try as you move through the rest of this
chapter.

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Figure 5.14 The Photo Filter icon in
the Adjustments panel.

Figure 5.15 The Photo Filter adjust-
ment has a number of presets you
can use.

Sample Adjustment: Photo Filter
Let’s create a special type of adjustment to give you some
practice at applying adjustment layers to your own images.
A photo ﬁlter adjustment layer allows you to shift the
overall color in an image. The effect is much like placing
a colored ﬁlter in front of a camera lens or putting on
colored sunglasses. If you were on a photo shoot, say with
Joe McNally, and he yelled out to you, “Grab a CTO,” you’d
promptly bring him a color temperature orange ﬁlter. A
photo ﬁlter adjustment layer is similar to this effect (with-
out Joe, of course).
Let’s give it a try. Open an image and choose Photo Filter
from the Adjustments panel (Figure 5.14). As soon as the
new adjustment layer is selected, its control options appear.
Choose a preset color from the Filter pop-up menu (Figure
5.15) or click the Color swatch to choose your own custom
color. Then adjust the Density setting to control how radi-
cally the ﬁlter will affect the image (Figures 5.16 to 5.18).

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Figure 5.16 The original image. (©2008 Dan Ablan.)

Figure 5.17 The photo filter adjustment with a Cooling Filter preset and 100% density.

Figure 5.18 The photo filter adjustment with a Warming Filter preset and 56% density.

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If the image is getting too dark as you increase the Density
setting, the Preserve Luminosity check box probably is
turned off. In that case, adding a photo ﬁlter adjustment
darkens the image, just as colored sunglasses allow less
light to enter your eye. Turning on the Preserve Lumi-
nosity check box prevents Photoshop from changing the
brightness of the image but still allows you to shift its col-
ors. Keep Preserve Luminosity turned on for most of your
images. Make a separate adjustment layer (Levels, Curves,
or some other type) if you want to change the brightness
of the image.
Since you probably haven’t read Chapter 7, “Setting Up
Images for Final Output,” here’s an advance peek into
color adjustments in Photoshop: When you use a photo
ﬁlter adjustment layer, you’re pushing all the colors in the
image toward one side of the color wheel. If the image has
an obvious color cast, all of the colors within the image will
be shifted to one side of the color wheel. When that’s the
case, you may be able to remove the color cast by apply-
ing a photo ﬁlter that uses the color directly across the
color wheel from the color that’s contaminating the image
(Figures 5.19 and 5.20).

Figure 5.19 The original image is okay, but might be a little
too warm due to white balance settings in the camera. The

Figure 5.20 A blue photo filter adjustment layer shifts the
color opposite and away from the green.

circled area on the color wheel represents the color case
within the image. (©2008 Dan Ablan.)

Now let’s start to explore the more powerful aspects of
adjustment layers.

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Blending Modes
The Blending Mode pop-up menu in the upper-left corner
of the Layers panel determines how the active layer will
interact with the underlying image. This menu can be
especially useful when applying adjustment layers, since it
allows you to limit how much those layers affect the image.
Three main blending modes are handy when using adjust-
ment layers:
 Hue blending mode allows an adjustment to change
the basic color of the underlying image while prevent-
ing the adjustment from changing the brightness
or contrast of the underlying image (also known as
tonality), or how colorful the image is (also known as
saturation). You would primarily use this mode when
you want to adjust the overall color of an image without
adding color to areas that are neutral gray (Figures 5.21
and 5.22). It can also be useful when you notice that a
color adjustment is making an image too colorful or is
mellowing the color too much.

Figure 5.21 A Hue/Saturation adjustment layer over-
compensates the color in the image with a Normal
blending mode.

Figure 5.22 Changing the blending mode to Hue keeps
the adjustment layer from affecting areas that are
neutral gray.

 Color blending mode allows an adjustment to affect
both the hue (basic color) and saturation (amount
of color) of the underlying image, while prevent-
ing the adjustment from changing the tonality of the

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image. Use this blending mode when you’re attempt-
ing to change the color of an image without shifting
the brightness in an undesirable way (Figures 5.23
and 5.24).
 Luminosity blending mode limits an adjustment so that
it can only affect the brightness and contrast of the

Later in this chapter, you’ll see how
the Normal and Pass Through set-
tings in the Blending Mode pop-up
menu can be used to affect a group
of adjustment layers.

underlying image, while preventing the adjustment
from changing the color of the image. This mode is
useful when you want to adjust the brightness of the
image without shifting the color or making the image
too colorful—a frequent consequence of darkening an
image (Figure 5.25).

Figure 5.23 A Curves adjustment
layer added to an image, with the
blending mode set to Normal.

Figure 5.24 The image from Figure
5.23, with the adjustment layer’s
blending mode set to Color.

Figure 5.25 The image and curve
adjustment from Figure 5.23, with
blending mode set to Luminosity.

(©2008 Dan Ablan.)
Using the pop-up Blending Mode menu at the top of the
Layers panel isn’t always the most ideal method for chang-
ing the blending mode of an adjustment layer, because
it’s only available after an adjustment has been applied.
If you’d like to choose a blending mode before applying
an adjustment, hold down Option/Alt when choosing an
adjustment type from the Adjustment Layer pop-up menu
at the bottom of the Layers panel, or from the Adjustments

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Figure 5.26 Holding down Option/
Alt when adding an adjustment layer
opens the New Layer dialog, which
offers a blending mode choice.

panel. That action opens the New Layer dialog, which
includes a Mode pop-up menu where you can specify the
blending mode you want for the adjustment layer you’re
creating (Figure 5.26).

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Empty Adjustment Layers
Adjustment layers and blending modes can be an effective
combination when applying the enhancement techniques
described in Chapter 9, “Enhancements and Masking.”
Adjustment layers can be used anytime that you would
usually duplicate a layer and change its blending mode. As
an alternative, you can use a blending mode that’s often
referred to as an “empty adjustment layer.” To do this,
create a new adjustment layer, but don’t change any of the

settings in the Adjustments panel (so the new adjustment
doesn’t change the appearance of the image). This tech-
nique works because Photoshop acts as if the adjustment
layer contains the result of the adjustment being applied.
Since an empty adjustment doesn’t change the image, it’s
considered to be identical to the underlying image.
The advantage of using an empty adjustment layer versus
duplicating a layer is that any future retouching applied to
the underlying image will automatically be reﬂected in the
empty adjustment layer (Figures 5.27 and 5.28)—it won’t
affect a duplicate layer.

Limiting Adjustments

Adjustment layers wouldn’t be so wonderful if they always
affected the entire image. To get adjustment layers to strut
their stuff, combine them with layer masks, which allow

Figure 5.27 You can create an
adjustment layer without any actual
adjustments, using it to apply a blend-
ing mode.

Figure 5.28 The same result as in Fig-
ure 5.27, using a duplicate image layer
rather than an adjustment layer.

you to limit which areas of the image will be affected by
each adjustment layer. Let’s look at all the ways in which we
can work with layer masks and adjustment layers.

Layer Masks
By default, each adjustment layer comes equipped with a
layer mask. This mask appears to the right of the Adjust-
ment icon. If no selection is present when the adjustment
layer was created, the layer mask will be entirely white.
In a layer mask, all white causes the adjustment to affect
the entire image. Black, on the other hand, prevents the
adjustment from affecting areas. To control where an
adjustment layer can affect an image, paint with black or

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white while the adjustment layer is active (Figure 5.29).
The black and white paint will appear within the Layer
Mask thumbnail image in the Layers panel.
Painting with black causes the image to revert to its
unadjusted state. Keep in mind that painting with black
won’t always cause drastic changes to the image. If the
difference between the original and the adjusted versions
of the image is subtle, painting with black will cause very
subtle changes to the image.

Figure 5.29 A layer mask allows you
to apply an adjustment in certain
areas. Here, our model is turned into
a lovely orange alien, except for her
eyes, which have been masked out.

If you get sloppy and paint with black over too large an
area, you can switch to painting with white, effectively
undoing your painting (since the layer mask started out
ﬁlled with white, and white areas allow the adjustment to
apply to the image).
You’re not limited to using the painting tools to modify a
layer mask. Any tool that works on a grayscale image can
be used to edit the layer mask. For example, you may like
to use the Gradient tool to create very gradual transitions
(Figures 5.30 and 5.31), and occasionally apply ﬁlters to a
mask to generate an interesting transition or to pull back
in areas that didn’t need adjustment.

Figure 5.30 A Curves adjustment layer
was added to enhance the trees in this
photo of New York’s Central Park, but
in doing so, sky detail has been lost.

Figure 5.31 Using a black-to-white
gradient mask, you gradually block
out the effects of the Curves adjust-
ment layer, revealing the original sky.

Working with Selections
If a selection is active at the time an adjustment layer is
created, the unselected areas will be ﬁlled with black in

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the resulting layer mask, preventing the adjustment from
affecting those areas. This approach confuses many users,
because the “marching ants” that indicate the edge of a
selection suddenly disappear when an adjustment layer is

created. That happens because the selection has been con-
verted into a layer mask (Figures 5.32 and 5.33).

Use the masking techniques
described in Chapter 9 to create a
selection, and then use that selec-
tion to limit which area of an image
is affected by an adjustment layer.

Figure 5.32 Once you’ve made a
selection in an image, you can apply
an adjustment to just that selection.

Figure 5.33 Apply an adjustment layer
to your selection, and the layer mask is
created for you automatically.

Using Quick Mask Mode
If painting on a layer mask is more convenient for you
than creating selections, but you’d prefer to isolate an area
before applying an adjustment, try this technique: Before
adjusting the image, press Q to enter Quick Mask mode
(which will not change the look of the image unless you
happen to have a selection active). Paint with black over
the areas you don’t want to be affected by the adjustment

you plan to make. The areas you paint over with black will
show up as a red overlay on the image (Figure 5.34). If you
accidentally cause the red overlay to appear on an area
that should be adjusted, paint with white to remove the red
overlay. Once the red overlay is covering all the areas that
shouldn’t be adjusted, press Q again to convert the Quick
Mask into a selection. With that selection active, create an
adjustment layer. The areas that appeared as red in Quick
Mask mode will be black in the layer mask attached to the
newly created adjustment layer, which will prevent the
adjustment from affecting those areas (Figure 5.35).

Figure 5.34 Painting in Quick Mask
mode. (©2008 Dan Ablan.)

Figure 5.35 When the adjustment is applied,
the Quick Mask selection is not affected.

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Disabling the Layer Mask
To see how an image would look if the layer mask wasn’t
limiting an adjustment, Shift-click the Layer Mask
thumbnail to disable the mask. A red X will appear over
the thumbnail to indicate that the layer mask has been
disabled temporarily (Figure 5.36). When you’re done
viewing the image in that way, Shift-click the Layer Mask
thumbnail a second time to turn it back on.

Viewing the Layer Mask Directly

Figure 5.36 The red X over the Layer
Mask thumbnail indicates that the
layer mask currently isn’t affecting the
adjustment.

When you paint on a layer mask, the resulting paint usu-
ally appears only in the tiny Layer Mask thumbnail image
in the Layers panel, where it may be difﬁcult to see what

you’re doing. To view the contents of the layer mask as a
full-sized image, hold down Option/Alt and click the Layer
Mask thumbnail in the Layers panel (Figure 5.37). You can
modify the layer mask while viewing it directly, or use this
view to inspect the results of painting on the Layer Mask
thumbnail and to clean up unexpected problems (such as
gaps between paint strokes). If you created a selection using
an automated selection technique (for example, Color
Range or the Background Eraser), you might notice some
noise in the layer mask. In that case, try using the noise
reduction techniques covered in Chapter 6, “Sharpening”
to rid the mask of the noise. When you’re done editing the
layer mask in this view, hold down Option/Alt and click the
Layer Mask thumbnail again.

Figure 5.37 Hold down the Option/Alt
key and click the Layer Mask thumbnail
to see the layer mask at full size for
easier masking.

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Viewing the Layer Mask as a Color Overlay
You can view the contents of a layer mask as a color overlay
on the image by pressing the backslash (\) key when an
adjustment layer is active. (This works much like Quick
Mask mode, as discussed earlier in this chapter.) Use the
color overlay to see how closely your painting matches the
subject of the photograph (Figure 5.38) and to touch up
the results by painting with black or white. When you’re
done using this view, press the backslash (\) key a second
time to turn off the color overlay. You can also modify the
color being used for the overlay by double-clicking the
Layer Mask thumbnail in the Layers panel (Figure 5.39).

Figure 5.38 Viewing the layer mask as a color overlay. (©2008 Dan Ablan.)

Moving or Copying the Layer Mask to Another Layer

Figure 5.39 Double-clicking the Layer
Mask thumbnail opens the Layer Mask
Display Options dialog, in which you
can specify the overlay color.

To drag a layer mask from one layer to another, all you
have to do is click in the middle of the Layer Mask thumb-
nail, drag the layer mask, and release the mouse button
after moving the mouse onto the target layer. If you’d
rather copy the layer mask instead of moving it, hold down
the Option/Alt key when dragging the layer mask.

Masking Multiple Adjustment Layers
To apply multiple adjustment layers to a particular area
of an image, select those adjustment layers, choose

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Layer > Group Layers, and then click the Layer Mask icon
at the bottom of the Layers panel to add a layer mask to
the group (Figures 5.40 and 5.41). Any changes made to
the layer mask that’s attached to the group will affect all
the adjustment layers within the group. You can even paint
on the layer mask attached to each adjustment layer, to
further limit where it can affect the image.

Limiting the Affected Brightness Range
To limit the brightness range that an adjustment layer is

Figure 5.40 Select the layers you
want to group.

Figure 5.41 Add a layer mask to
the group to mask all the layers
within the group.

able to affect, double-click to the right of the adjustment
layer’s name and adjust the blending sliders at the bottom
of the Layer Style dialog (Figure 5.42).
The sliders under the This Layer heading analyze the
result of the adjustment being applied and allow you to
hide the dark (left slider) or bright (right slider) portions
of that result so that you can see the underlying image
(which is usually the original photograph). The sliders
under the Underlying Layer slider cause the dark (left
slider) or bright (right slider) portions of the original
image to show through and therefore prevent the adjust-
ment from affecting those areas. You can hold down
Option/Alt and drag any of the sliders to split it into two
halves, which will produce a gradual transition between
the area that’s being hidden and the rest of the image

(for a more detailed explanation of the blending sliders,
see Chapter 9).

Figure 5.42 To limit brightness
affected by an adjustment layer, adjust
the blending sliders in the Layer Style
dialog.

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Blending sliders are particularly useful when darkening
or adding contrast to part of an image using a Levels or
Curves adjustment layer. Sometimes certain areas of an
image change too much as you make an adjustment. By
using the blending sliders to let only parts of the under-
lying image show through, you can prevent the adjustment
from affecting the entire image.
You can also use blending sliders when colorizing an
image. Create a Hue/Saturation adjustment layer (Figure
5.43) and turn on the Colorize check box to add some
color. Then double-click just to the right of the adjustment
layer’s name to open the Layer Style dialog. Drag the white
value of the Underlying Layer slider to the left, allowing
the green of the underlying image to blend through the
adjustment layer, and effectively limiting the effect of the
colorized adjustment layer. (Split the sliders rather widely
apart to ensure a smooth transition.) This trick is what
usually separates realistic-looking images from fake-looking
ones, because not much color shows up in the darkest
areas of most color photographs (Figure 5.44).

Figure 5.43 The original image, with
an adjustment layer added.

Figure 5.44 The result of using the blending sliders to limit how much
color from the adjustment layer is applied.

Limiting the Layers Affected by an Adjustment Layer
The techniques we’ve talked about up until now work great
when you’re working with single image documents. When
you graduate to more complex collages that contain a
multitude of images and many layers, you’ll have to supple-
ment those techniques with ones that allow you to control
the number of layers affected by an adjustment.

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Adjusting a Single Layer
You can limit an adjustment layer to affecting a single layer
by creating a clipping mask. To try this technique, create a
new adjustment layer and hold down the Option/Alt key
when choosing an adjustment either from the Adjustment
Layer pop-up menu at the bottom of the Layers panel, or
from the Adjustments panel. When the New Layer dialog

Figure 5.45 Create an adjustment
layer while holding down the Option/
Alt key; then choose Use Previous
Layer to Create Clipping Mask.

appears, turn on the Use Previous Layer to Create Clipping
Mask check box. A small down arrow appears in the adjust-
ment layer, indicating that the adjustment layer applies
only to the underlying layer (Figures 5.45 and 5.46).

Figure 5.46 When the adjustment
layer is added to the Layers panel, it’s
indented slightly and displays a down
arrow pointing to the layer beneath.
To clip more than one adjustment
layer to a single layer, hold down
the Option/Alt key and click the
horizontal line that separates the
adjustment layers from the layer
you want to adjust. When using
this technique, start from the

bottom adjustment layer and work
your way up to the top adjustment
layer that you want to apply to the
image.

To add a clipping mask to an existing adjustment layer,
position the adjustment layer directly above the layer you
want to affect, click the adjustment layer to select it, and

choose Layer > Create Clipping Mask.

Adjusting a Limited Number of Layers
There are two methods for causing one or more adjust-
ment layers to affect a limited number of layers:
 Group the layers into a folder. Start by selecting the
adjustment layers and all the layers they should affect
(Figure 5.47). To place those layers into a group, hold
down Shift and click the Group icon (which looks like
a folder) at the bottom of the Layers panel. Then click
the newly created group and change the setting in the
Blending Mode pop-up menu at the top of the Layers
panel: Pass Through allows the adjustments to affect
layers that are outside the group. Normal limits all
adjustment layers and blending modes used within the
group to affecting the layers within the group (Figures
5.48 and 5.49).

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II: Production Essentials

Figure 5.48 Change the blending
mode to Pass Through.

Figure 5.49 A group set to Normal
blending mode. By moving the

Group 1 layer to the top of the
layers, you can really change the
group effect.

Figure 5.47 Select the image and
adjustment layers you want to group.

 Group the layers into a Smart Object. Adjustment lay-
ers contained in a Smart Object cannot affect layers
that appear outside of the Smart Object. As with the
previous technique, start by selecting the adjustment
layers and all the layers they should affect, but this time
right-click in the Layers panel (somewhere away from
the icons) and choose Convert to Smart Object, which
causes all the selected layers to be encapsulated into a
single Smart Object layer (Figures 5.50 and 5.51).

Figure 5.51 The converted Smart
Object in the Layers panel.

Figure 5.50 Select the image and
adjustment layers; then right-click in
the Layers panel and choose Convert
to Smart Object.

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Chapter 5 Adjustment Layers

To edit the contents of the Smart Object layer, double-
click the Smart Object layer’s thumbnail image in the
Layers panel, which causes the encapsulated layer to
appear as a separate layer. This is the preferred method
when you plan to drag the affected layers into a more
complex document, because it simpliﬁes the Layers
panel view of the image (which usually reduces con-

206

Figure 5.52 This image contains
bright and dark areas that are not
part of the actual photograph.
(©2008 Dan Ablan.)

Figure 5.53 The histogram analyzes
the entire image, including its border
and background.

Figure 5.54 The Layers panel here
includes an adjustment layer with a
layer mask that’s partially filled with
black.

Figure 5.55 This histogram analyzes
only the selected area of the image.

fusion when working with complex documents). For
more information on working with Smart Objects,
check out Chapter 10, “Collage Effects.”

Histograms and Automatic Adjustments

When you work with images that contain large areas of
white/black (like ones with fancy borders, as in Figure 5.52),
the Histogram panel can be less than useful, because the
histogram indicates that the image contains the full range
of brightness levels (Figure 5.53)—even though the image
itself (minus the border) might be rather low-contrast. To
get around this problem, you’ll need to take steps to limit
what the histogram examines when analyzing the image.
You need to optimize the contrast of the important areas
of the image, without having to look at spikes at the ends of
the histogram that reﬂect the large areas of black or white
in the border area. You can also use this technique when
you want to enhance the contrast of an image radically,
while retaining detail only in the most important areas.
To limit the histogram, select the important areas of the
image and then create a Curves adjustment layer by click-
ing the Curves icon in the Adjustments panel. When a
selection is active, the histogram analyzes only the selected
area, but the moment you create an adjustment layer, it
analyzes the entire image again because the selection is
converted into a layer mask. Now, look in the Layers panel
(Figure 5.54) and Command/Ctrl-click the black-and-white
Layer Mask thumbnail on the Curves adjustment layer you
just created. That action brings your selection back and
limits the area of the image that the histogram analyzes
(Figure 5.55). Now you can go to the Adjustments panel
and adjust away.

II: Production Essentials

When you use this technique, the adjustment applies only
to that same selected area (Figure 5.56). But don’t worry—
as long as you used an adjustment layer, you’ll be able to
force the adjustment to apply to the entire image. The
layer mask that’s attached to the adjustment layer should
contain some black, limiting the areas of the image to
which the adjustments apply. All you have to do to get the
adjustment to apply to the entire image is choose Select >
Deselect, press D to reset the foreground color, and then
press Option-Delete (Mac) or Alt-Backspace (Windows) to
ﬁll the Layer Mask thumbnail on that layer with white. This
trick adjusts the whole image (Figure 5.57); the histogram
only looks at the selected area of the image—but in the
end, the adjustment applies to the entire image. It sounds
like a lot of steps, but a few times doing this procedure and
it becomes second nature.

Figure 5.56 The adjustment is affect-
ing only the selected areas.

When a layer mask is active,
resetting the foreground and

Figure 5.57 After you fill the Layer Mask thumbnail with white, the adjustment
affects the entire image.

background colors changes the
foreground color to white and the
background color to black—the
opposite of what you get if the layer
mask isn’t active.

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Chapter 5 Adjustment Layers

Potential Problems

Working with adjustment layers is usually a trouble-
free experience, but a few areas can cause unexpected
problems:
 If you drag an image along with its adjustment layers to
another document, the adjustment layers will affect the
entire destination document. To prevent this problem,
use the techniques mentioned earlier in this chap-
ter (such as clipping masks) to limit which layers are
affected by the adjustment layers before you drag them
to the destination document.
 Be careful when changing the color mode of an image;
for example, when changing RGB to CMYK. Certain
adjustment layers won’t make the transition, and others
will produce different results. For that reason, it’s best
to ﬂatten the image before changing the color mode.
 If you’re working with 16-bit images in Photoshop, but
you need to end up with an 8-bit version, ﬂatten the
image before making the conversion. If you retain the
layers, they’ll be recalculated using the 8-bit version of
the image, which will cause you to lose any quality dif-
ference you would have had from working with a 16-bit
image. Flattening the image will cause the adjustments
to be applied to the full 16 bits of data, producing a
higher-quality 8-bit result.
 Be careful when retouching an image that contains
adjustment layers; otherwise, you might cause the
adjustments to apply to the image twice. For more
information about how to avoid this problem, check
out the bonus video “Workﬂow” at www.danablan.com/
photoshop.
 It’s difﬁcult to make radical adjustments to isolated
areas without causing an obvious transition between the
adjusted area and the surrounding image. This prob-
lem can often be remedied by placing an empty layer
at the top of the layers stack and then retouching the
transition area with the Healing Brush to blend both
sides of the transition, creating a smooth blend.

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II: Production Essentials

Limitations of Adjustment Layers

One limitation of adjustment layers prevents certain
adjustments from being available as an adjustment layer:
An adjustment layer must be able to be fed a single pixel
and ﬁgure out how it should be modiﬁed, without having
to rely on the information contained in the surrounding
image. The Match Color, Replace Color, Shadows/High-
lights, Exposure, and Equalize adjustments must be able to
compare the area being adjusted to the surrounding image
(or a second image) to determine how to adjust the image,
which prevents them from being used as adjustment layers.
Five adjustments are not found in the Adjustment Layer
pop-up menu at the bottom of the Layers panel: Auto Lev-
els, Auto Contrast, Auto Color, Desaturate, and Variables.
These are really shortcuts for using adjustments in certain
ways. You can use the following equivalents to get the same
functionality in an adjustment layer. (Note that after the
Curves or Levels adjustment layer is applied, you need to
click the Adjustments panel side menu and choose Auto
Options, or Option/Alt-click the Auto button, to see the
Auto Levels, Auto Contrast, and Auto Color choices.)
 Auto Levels is the same as clicking the Options button
in the Levels or Curves dialog and choosing Enhance
Per Channel Contrast while leaving the other settings at
their defaults.
 Auto Contrast is the same as clicking the Options
button in the Levels or Curves dialog and choosing
Enhance Monochromatic Contrast while leaving the
other settings at their defaults.
 Auto Color is the same as clicking the Options but-
ton in the Levels or Curves dialog and choosing Find
Dark & Light Colors while leaving the other settings at
their defaults.
 Desaturate is the same as moving the Saturation slider
in the Hue/Saturation dialog to -100.
 Variations is a visual interface for a combination of the
Saturation slider in Hue/Saturation, the Brightness
slider in Brightness/Contrast, and the choices available
in the Color Balance dialog.

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Chapter 5 Adjustment Layers

Final Notes on the Adjustments Panel

As you’ve seen, the new Adjustments panel in Photo-
shop CS4 makes it very easy to add an adjustment layer
to an image quickly. But you can go one step further by
using the various supplied presets. Figure 5.58 shows the
expanded Adjustments panel with the Channel Mixer
Presets expanded. By simply clicking one of these presets,
you add that preset to the Layers panel. You don’t need to
add an adjustment and then choose the preset—just click
the preset and you’re ready to go. A good way to work is to
choose a preset to get you most of the way there, and then
make minor modiﬁcations to suit that particular image.

Figure 5.58 The Adjustments panel
comes with a number of presets that
allow you to add an adjustment layer
in one click.

At the very bottom of the Adjustments panel is a small
icon (Figure 5.59) that allows you to toggle between two
settings: New Adjustments Affect All Layers Below, and
Clipping the New Layer. In most situations, as you’ve seen

throughout this chapter, you don’t need to use this option.

Figure 5.59 Use this icon in the
Adjustments panel to clip a new layer.

The Next Step

I hope that this chapter not only has inspired you to use
adjustment layers, but demystiﬁed them. If you commit to
using adjustment layers, you’ll soon wonder how you ever
lived without them.