Pixology Magazine

Pixology
The Magazine for Photographers
April 2013
Converting to CMYK
Merging Lightroom Catalogs
Noise Reduction Strategies
Pixology
The Magazine for Photographers
CONTENTS
4 Fast Color Fix
9 Converting to CMYK
20 Merging Catalogs
4
25 Noise Reduction Strategies
33 Finding Celestial Bodies
25
38 Sketch Effects in Elements
47 Fun with the Sun
38
From the Editor
So, while I can’t yet focus on
wildflowers, lush landscapes, and other
springtime photographic opportunities,
I can give some thought to spring
cleaning. Perhaps that is what inspired
some of the articles in this issue,
including a look at how to cleanup
multiple Lightroom catalogs into one,
and a reminder to make sure your lens
is clean before capturing images with
the sun in the frame.
I hope you find this issue of Pixology
to be informative and entertaining, and
hopefully we can all enjoy some spring
weather soon.
As always, I welcome your thoughts via
email at [email protected].
Thank you,
Tim Grey
Editor
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Spring has arrived, but here in Austria
where I’m writing this issue of Pixology
magazine, the weather is still very much
winter weather. Somehow that only
serves to further remind me that spring
has arrived, even if it doesn’t feel like it.
3
Fast Color Fix
Removing a Strong Color Cast
By Tim Grey
Every now and then I’m surprised when I receive an unexpectedly strong favorable response to
a particular technique. I guess sometimes I just figure a particular technique won’t have wide
appeal or won’t seem all that impressive. Such is the case for a technique for removing a very
strong color cast in an image that I teach periodically.
I first started using this technique when I had an old family photo that experienced a very strong color
shift after having been stored for years in a family album that was far from archival. Well, actually, the
photo had been stored for decades. But the point is, the color had shifted quite significantly.
I realized that a combination of a couple of features in Photoshop (or Photoshop Elements)
would likely provide a solution. Sure enough, I was able to quickly and easily compensate for the
strong color cast using the technique presented here. It’s worth noting that if you will be working
to correct a large number of photos that have experienced a strong color shift you can create an
action in Photoshop to automate the steps of this process.
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1 - Duplicate the Background Layer
This process involves some rather dramatic
changes to pixel values, and so in order to
preserve the original image while improving
the color, you’ll need to create a copy of
the Background image layer. You can do
so by clicking on the thumbnail for the
Background image layer on the Layers panel
and then pressing Ctrl+J on Windows or
Command+J on Macintosh, or by dragging
the thumbnail for the Backround image
layer to the Create New Layer button at the
bottom of the Layers panel.
2 - Apply the Average Blur Filter
With a duplicate layer created, the next
step is to determine the average color of the
image, which will effectively provide you
with an indication of the color of the strong
color cast. To achieve this effect, choose
Filter > Blur > Average from the menu. This
filter will produce a result that represents a
blur so strong that every pixel becomes the
color of the average color in the image. In
other words, the Background Copy layer
will now consist of a single solid color
that represents the average color from the
Background image layer.
3 - Invert the Color
Since the average color on the Background
Copy layer represents, in essence, the color
problem in the image, the solution to the strong
color cast lies in the opposite color. To change
the color of the Background Copy layer to the
opposite color, choose Image > Adjustments
> Invert from the menu. The color of the
Background Copy layer now represents the
color that needs to be used to compensate for
the strong color cast in the photo.
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4 - Set the Blend Mode to Color
To actually apply the change in color for the
original image, you’ll need to employ the
Color blend mode. Simply choose Color from
the blend mode popup (the default value is
Normal) on the Layers panel. This will shift
the image from an original that had a very
strong color cast, to an image with an even
stronger opposite color cast.
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5 - Reduce Layer Opacity
At this point the effect is, of course, far too
strong. The image is effectively a black and
white image with a tint applied, meaning the
image is comprised entirely of various shades
of a single color. To tone down this color, and
achieve a result that neutralizes the original
color cast, simply reduce the Opacity value on
the Layers panel.
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In most cases an Opacity value of around
50% will provide a good balance, since we’re
literally offsetting the original color cast with
its opposite value. However, you may need to
shift the value up or down a little depending
on the specific results you’re after.
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6 - Apply Additional Adjustments
After applying such a strong (though
relatively simple) adjustment to compensate
for a very strong color cast, the image
will be looking a bit drab. Therefore,
you’ll want to apply some adjustments to
improve the appearance of the photo. At
a minimum, you’ll likely want to increase
contrast, such as with a Levels or Curves
adjustment. You may also need to apply an
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adjustment to improve overall saturation,
such as via Vibrance or Hue/Saturation.
Other adjustments may also be called for,
but having quickly and easily improved the
overall color for the photo, you’ll be off to a
great start for further optimization.
8
Converting to
CMYK
By Tim Grey
Most photographers are, I suspect, familiar with at least the basics of the
RGB color model. However, in my experience, it is somewhat rare for
a photographer to have any significant knowledge of the CMYK color
model. Even more rare, it seems, is a photographer who understands the
issues related to converting an image from an RGB color space to CMYK.
Color Model Basics
Color models derive from a need to be able
to precisely and consistently describe colors.
In effect, a color model defines a common
language for describing color. Ultimately,
specific color values in a given color space
can be mapped to a specific response in the
human visual system. There are obviously
a huge number of variables at play, but the
bottom line is that a color model exists to
enable us to describe color.
For photographers, the most familiar color
model is RGB. With this color model each
individual color value is defined based on
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how much red, green, and blue light get
added up to create a specific color value.
All three colors at the minimum value will
produce black, and all three colors at the
maximum value will produce white. Every
other possible color is created with values in
between those extremes.
This is a logical approach to describing color
for photographic images, since the RGB
color model uses light values to describe
color. Most digital camera image sensors
capture red, green, and blue values at the time
of exposure, and most computer monitor
displays also emit light that is comprised of
individual red, green, and blue values.
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The CMYK color model, on the other hand,
really revolves around ink on paper. While
the RGB color space describes color values
based on how much light of each color (red,
green, and blue) are added together, the
CMYK color space relates to how much of
each ink color (cyan, magenta, yellow, and
black) must be mixed together to create the
color for each pixel in the image
being printed.
The primary colors for the CMYK color
model are cyan, magenta, and yellow. These
primary colors are often referred to as the
subtractive primary colors, because ink on
paper absorbs light, and thus is subtracting
light from rather than adding light to the
values we are able to observe with our eyes.
In theory the CMYK color model could be
simply the CMY color model, comprised of
just cyan, magenta, and yellow. Black is added
only because the inks we use are not pure
enough to create a true black by blending
only cyan, magenta, and yellow ink. Thus,
black is added to the mix. As to why black
is represented as “K” rather than “B”, that
depends upon whom you ask. Some will
tell you black is referred to as “K” to avoid
confusion with blue. Others will tell you that
black is designated with a “K” because black
is the key color for alignment when printing
in an offset press environment.
The RGB and CMYK color models are
obviously based on different—in fact
opposite—primary colors. But both are
aimed at enabling us to describe color very
specifically, whether we’re describing colors
based on how much light is being added to
the equation or how much ink is being put
down on paper.
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The Need for CMYK Conversion
It makes sense that our digital cameras
typically capture RGB values, since the RGB
color space relates to light and the camera is
quite literally capturing light. It also makes
sense that we work in an RGB color space
in most cases when optimizing our images,
because we are using an RGB device as a
monitor to view the image while we work.
When it comes to printing, it also makes
sense that we would need to translate our
RGB pixel values to CMYK color values,
since we are printing with CMYK inks.
However, that is not always the case.
For example, a typical photo inkjet printer
utilizes a variation on a CMYK ink set,
generally with multiple shades of certain
(or all) of the primary colors in order to
improve the color gamut for the printer.
However, these printers are designed to
process RGB values, and thus should be
treated as RGB devices. As such, you should
not convert your digital images to CMYK
before printing to a photo inkjet printer, and
in fact the ICC profiles for these printers are
RGB profiles.
In the world of “traditional” printing,
however, CMYK color values are the norm,
and thus pixel values need to be translated to
CMYK for printing in most commercial
print environments.
Who Should Convert?
I have long advocated that in most cases
photographers should not convert images to
CMYK when a commercial printer will print
their images. Instead, I recommend sending
RGB files, along with a sample print, so the
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printer can perform the conversion and other
preparation, and utilize the sample print as a
reference to help ensure the results match the
photographer’s intent.
However, some clarification is in order here.
First, I generally refer to “the printer” as
though it were a single person taking the
photographer’s images and operating an
offset press to print those images. Things are
obviously not that simple in most cases. To
begin with, there are typically more than a
few people involved in the overall process
of preparing images and other documents,
creating print-ready files, and producing
the final output. Furthermore, these various
people are often not working at the same
company, or even in the same country.
It is therefore important to keep in mind
that there are only certain portions of the
workflow where a conversion to CMYK can
be performed, and thus only certain people
involved who are able to perform
this conversion.
My reasoning for having “the printer”
perform the CMYK conversion is not to
simply avoid taking responsibility for the
conversion, or to be lazy or cheap when
it comes to that additional work. Rather,
my feeling is that the people involved in
the actual pre-press or printing process
are generally the most knowledgeable and
best equipped when it comes to actually
converting RGB images to CMYK.
In my opinion, photographers should not
simply “pass the buck”, leaving the print
shop to do all the work of preparing images
for print. The photographer also should not
assume that having their images converted
from RGB to CMYK is something that should
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be done for free. This CMYK conversion is
part of a larger process of ensuring accurate
printing of the best quality possible. If a
photographer cares about how their images
look in print, they should be willing to either
learn to perform these tasks on their own
or be willing to pay for the services of the
printing staff.
Start by Talking
Regardless of whether you or the printing
staff will be preparing the final images for
print, it is critical that you start the process
with a conversation. A good relationship with
the printer will help ensure you’re able to get
assistance when you need it, and will also
help ensure there are no misunderstandings
along the way.
When it comes to commercial printing,
one of my greatest frustrations is when you
contact the printer and then tell you that
you must convert the images to CMYK, and
that to do so you can simply choose Image
> Mode > CMYK Color from the menu in
Photoshop. This is simply bad advice if there
isn’t additional information provided. So bad,
in fact, that I recommend if at all possible that
you find another printer (or at least talk to
someone else at the same printer) if you hear
this recommendation.
The challenge here is that CMYK profiles
are device-dependent profiles, meaning they
describe a color gamut of only a specific print
configuration. The color gamut of a specific
printer, ink, and paper combination will be
smaller than your monitor’s display profile
as well as the RGB working space profile
you were using while optimizing the photo.
Therefore, a conversion to CMYK that doesn’t
take into account the specific capabilities of
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the output process
to be used will
compromise the final
color gamut and
overall quality of the
printed result.
Under ideal
circumstances you’ll
be able to obtain a
custom CMYK ICC
profile from the
The Customize Proof Condition dialog allows you to establish settings for the Proof Colors display,
printer, so you can
which enables you to view a soft proof of your image that will simulate the final print.
use that profile in
a print shop has many more pressing tasks
the process of softto perform than to generate ICC profiles for
proofing your images as well as converting
every print job for all of their customers.
those images to that CMYK profile. In reality,
this isn’t very likely to occur, for a wide
That said, if you’re able to obtain a custom
variety of reasons. Put simply, the world of
profile for the output conditions your images
commercial printing is far more complex
will be printed under, so much the better.
than photo inkjet printing. As a photographer
But regardless of whether you receive a
you probably own one or two photo inkjet
profile for the conversion process, you should
printers, and you probably use a single ink
most certainly be able to obtain specific
set for each. You may even have two printers
instructions for how the images should
that use the exact same ink set. You probably
be converted.
utilize a relatively small number of papers for
most of your printing, using a single paper
Soft Proofing
for most printing, and then a handful of other
papers for specialty printing.
When it comes to printing directly to a
With commercial printing you may work
with a small shop with only one press, but
even then the range of potential ink and
paper combinations is virtually unlimited.
Worse, ink and paper may be switched from
job to job, and from print run to print run,
and often in a somewhat unpredictable way.
In other words, the printer likely can’t provide
you with an ICC profile for the specific print
conditions your images will be printed under,
in large part because it may be difficult to
predict exactly what those output conditions
will be. And of course, to be fair, the staff at
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photo inkjet printer, I rarely feel the need
to perform soft proofing. That’s because I
generally am working with accurate ICC
profiles, and with a printer, ink, and paper
combination I’m familiar with. As a result, I
typically am able to achieve predictable and
consistent output without any difficulty.
However, when sending an image to a third
party to be printed, soft proofing can be
very helpful. The results will vary depending
on whether you’re using a custom printer
profile for the specific output conditions
or you’re using a generic profile based on
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recommended settings. But the idea is that
soft proofing can help you get a better sense
of what to predict in terms of the final print.
Soft proofing involves adjusting the onscreen display to simulate the results you can
expect from the printed image. Because your
computer display is using emitted light to
present the image, and a print depends upon
reflected light, the experience of viewing
each is quite different. Therefore, you should
think of soft proofing as a tool to help you
anticipate what the printed image will look
like, not a perfect preview of the final output.
Before enabling the soft proofing display,
you’ll need to configure the settings for Proof
Setup. Start by choosing View > Proof Setup
> Custom from the menu to bring up the
Customize Proof Condition dialog. From
the Device to Simulate popup, choose the
appropriate profile based on the settings
specified by the printer, and as outlined later
in this article. Be sure the Preserve CMYK
Numbers checkbox is turned off, as having
this checkbox turned on counteracts the
effect of soft proofing. Set the Rendering
Intent popup and Black Point Compensation
checkbox similarly based on your CMYK
conversion settings.
While it can be a bit alarming to see the
dramatic change in the image, it is generally
best to turn on both the Simulate Paper
The Proof Colors view option enables you to view a soft proof that simulates what the final print should look like. In some cases
the result can be rather dramatic, as shown here. The left image is the standard RGB display, while the preview on the right is for a
CMYK profile for an uncoated newsprint media.
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Color and Simulate Black Ink checkboxes if
available. This will provide the most realistic
preview of what you can expect the print to
look like, compensating to the extent possible
for the experiential differences between a
monitor display and printed image.
With the settings established in the
Customize Proof Condition dialog you can
click the OK button to close the dialog. The
Proof Colors option will be turned on by
default, meaning the image will continue
to reflect the soft proofing display. You can
toggle the soft proof display on or off by
choosing View > Proof Colors from the
menu, or by pressing Ctrl+Y on Windows or
Command+Y on Macintosh.
In addition to the soft proofing display,
you can also turn on an overlay that will
indicate the areas of the image that are
outside the color gamut for the current
proof condition. To turn on this option,
choose View > Gamut Warning from the
menu, or press Ctrl+Shift+Y on Windows
or Command+Shift+Y on Macintosh. The
default color for the out-of-gamut overlay
is gray, but you can also change this setting
in the Transparency & Gamut section of the
Preferences dialog in Photoshop.
Of course, besides enabling you to get a sense
of what the print will actually look like, you can
also use the soft proofing display as a guide for
applying adjustments in an effort to compensate
to the extent possible for the limitations of
the printer, paper, and ink combination to be
used for printing. Keep in mind that these
adjustments will never enable the print to look
exactly like your original optimized image on
your monitor display, but you can certainly
apply some basic adjustments to make the most
of the printed result.
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With the Gamut Warning option turned on as part of the
Proof Colors view option, a gray overlay will appear over
areas of the image that fall outside the color gamut of the
printer, ink, and paper combination represented by the profile
established for the Proof Colors display.
Individual Conversion to CMYK
There are two basic processes you can use to
convert an image to CMYK in Photoshop.
Both will achieve the same result, so it is
mostly a matter of personal preference or
workflow approach.
The first approach to converting to CMYK
is to choose Edit > Convert to Profile from
the menu. This will bring up the Convert
to Profile dialog, where you can choose
the specific profile to be used as well as the
settings for the conversion. You must specify
a particular CMYK profile to convert to as
part of this process.
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If you received a
custom ICC profile
from the printer,
you’ll need to install
that profile on your
computer, and then
select the profile
as the Destination
Space Profile in the
Convert to Profile
dialog. In the
absence of a custom
ICC profile, you’ll
need to select the
profile recommended The simplest way to convert an image to CMYK is to use the Convert to Profile command,
by the printer.
establishing settings for the conversion in the Convert to Profile dialog.
In many cases
conversion. This relates specifically to how
you’ll likely find
colors that fall outside the color gamut of
that profile recommendation is either U.S.
the destination profile will be dealt with. In
Sheetfed Coated or U.S. Sheetfed Uncoated,
most cases I prefer the Relative Colorimetric
depending on the type of paper being printed
option, because it preserves the appearance
to. It is worth noting that in my experience
of all colors that fall within the color gamut
the default CMYK working space profile in
of the destination space. Only colors that fall
Photoshop, which is U.S. Web Coated, is not
outside the destination color gamut will be
the best choice for most commercial
shifted to the closest matching color that is
print jobs.
within the color gamut.
In most cases the default settings in the
However, in some cases you may get better
Conversion Options section of the Convert
results with the Perceptual rendering intent,
to Profile dialog will work perfectly well.
especially when the source color space has
However, if recommended by the printer, you
a significantly wider color gamut than the
may need to adjust these settings. The Engine
destination color space. This is because the
option determines which color management
Perceptual rendering intent maintains the
processing engine will be used to calculate the
relative relationships between colors. The
change in pixel values from one color space to
drawback, however, is that the Perceptual
the next. The default is Adobe (ACE), which
rendering intent effectively reduces saturation
is generally the best choice because it is a
for all colors rather than focusing only on the
cross-platform solution. However, in some
colors that are outside the color gamut for the
cases the printer may recommend using the
destination space. But again, the best option
platform specific conversion engine for either
depends on the specific output conditions,
Windows or Macintosh.
and the relationship between the source and
The Intent popup allows you to choose
destination color spaces.
a specific rendering intent for the color
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The Use Black Point Compensation checkbox
determines whether black in the source color
space for your image should be mapped
to black in the output space. In most cases
you will want this option turned on, unless
instructed otherwise by your printer.
image. With the checkbox turned on you’ll
see a preview of the final effect in the image
after the conversion. This can be helpful
in getting a better sense of the degree of
compromise involved in the color potential of
the intended output.
The Use Dither checkbox will help ensure
smoother gradations of color in images
where there are significant issues related
to color gamut. This is only an issue for
8-bit per channel images, and therefore this
checkbox is disabled when you are working
with a 16-bit per channel image. For 8-bit
per channel images it is best to leave the Use
Dither checkbox turned on to help ensure the
smoothest gradations in situations where that
is an issue.
Once you’ve established the appropriate
settings in the Convert to Profile dialog, click
OK to apply the change. The image can then
be saved for delivery to the printer.
Finally, you have the option to flatten the
image in order to preserve the appearance
of color and tonal values within the photo.
In most cases I would consider this a
superfluous option, because I recommend
creating a flattened copy of your master
image before you start preparing that
copy for output. If you are working with a
layered image for any reason at this point, I
recommend turning on the “Flatten Image
to Preserve Appearance” checkbox, as it will
help prevent unwanted shifts in color that
can occur when there are adjustment layers
applied to an image.
It is worth noting that you can toggle the
Preview checkbox off and on in the Convert
to Profile dialog to evaluate the “before”
and “after” view relative to the actual color
conversion. With the Preview checkbox
turned off you’ll be viewing the image as it
would normally appear within Photoshop,
such as when you are working to optimize the
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Conversion via Color Settings
The other option for converting an image
to CMYK is to change the Color Settings
so the desired output profile is established
as the Working Space for CMYK. With the
appropriate settings established in the Color
Settings dialog you can then simply choose
Image > Mode > CMYK Color from the
menu to convert the image. It is important
to keep in mind that adjusting the options
in Color Settings is critical to this process,
as otherwise you are “blindly” converting
the image to whatever profile happens to be
established as the working space for CMYK.
To adjust the settings, first bring up the
Color Settings dialog by choosing Edit >
Color Settings from the menu. Choose the
appropriate profile from the CMYK popup
in the Working Spaces section of the Color
Settings dialog. This will be either the custom
ICC profile provided by your printer and
installed on your computer, or the generic
profile recommended by the printer.
In the Color Management Policies section
of Color Settings, I recommend setting
the CMYK popup to Preserve Embedded
Profiles. This will ensure that if you open
an image that is already in the CMYK color
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space, the profile
will not be changed
to the profile you’re
establishing as
your working space
automatically. You
may also want to
turn on the three
checkboxes at the
bottom of the Color
Management Policies
section of Color
Settings so you’ll
be warned if there
are issues with a
profile mismatch or a
missing profile for
an image.
The Conversion
Options section
contains the same
basic settings as the
The Color Settings dialog enables you to establish a default color space for CMYK images, which
Convert to Profile
can then be used as the basis of a CMYK conversion via the Image > Mode menu.
dialog, and the same
not applicable to a conversion to CMYK.
decisions apply.
Therefore, those settings don’t need to be
Therefore, you can refer to the explanation
adjusted for purposes of a CMYK conversion.
outlined earlier in this article for information
on establishing the best settings for the
After establishing options for CMYK in the
Conversion Options section of the Color
Color Settings dialog, you can convert an
Settings dialog.
image to the destination CMYK profile you’ve
defined by choosing Image > Mode > CMYK
The only additional item in the Conversion
Color from the menu.
Options section of the Color Settings dialog
that isn’t included in the Convert to Profile
dialog is the “Compensate for Scene-referred
Custom CMYK Settings
Profiles” checkbox. This option, however,
In rare cases you may be instructed to use
is only applicable to video, not still images,
custom settings for the CMYK profile, which
and thus photographers don’t need to be
enables a considerable amount of control
concerned about this checkbox.
over the specific processing of color values in
The Advanced Controls section of the
the image when the color is converted from
Color Settings dialog will be displayed if
RGB to CMYK. The Custom CMYK settings
you have clicked the More Options button,
should only be adjusted based on specific
but that section contains options that are
instructions from the printer.
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To adjust the Custom
CMYK settings, start
by choosing Edit >
Color Settings from
the menu. In the
Color Settings dialog,
choose Custom
CMYK from the
CMYK popup in
the Working Spaces
section. This will
bring up the Custom
CMYK dialog,
where you can adjust
settings for the ink
and color separation
based on the specific
instructions provided
to you by the printer. The Custom CMYK dialog enables you to establish detailed settings for a CMYK conversion, but
After establishing
should only be used with specific guidance from the commercial printing staff you are working with.
the recommended
preference is to save to a dedicated folder
settings, type a meaningful name in the Name
on the Desktop, so that the files are easier to
field, and click OK to both establish the
get to and thus easier to transfer to another
settings and save the Custom CMYK option
device or upload to a server in order to
with a name that can later be selected from
deliver those files to the printer.
the CMYK popup in the Working Spaces
section of the Color
You can also specify a new filename for the
Settings dialog.
image you’re saving, although it is generally
Saving the Converted Image
Once you have converted the current image
to the desired CMYK profile, you’ll naturally
need to save the image so it can be delivered
to the printer for final output. In most cases
you’ll want to save the image as a TIFF image,
though the specific file format and settings
will depend upon the preferred workflow of
the printer who will produce the final result.
To save the image, start by choosing File >
Save As from the menu to bring up the Save
As dialog. Navigate to the location where
you want to save the images. My general
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best to use the original filename in order
to avoid confusion about where the source
image is for a particular derivative image
you’ve created for printing. If the printer
prefers a different structure for the filename,
such as to include your name at the beginning
of the filename, I recommend incorporating
your original filename at the end of that new
filename to enable you to cross-reference
the files.
You can then specify the type of file you’ll
be saving from the Format popup, though
again you will most likely be utilizing the
TIFF file format.
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Most importantly,
be sure the Embed
Color Profile
checkbox is turned
on. To the right of
the label for this
checkbox you’ll
see an indication
of the name of the
profile that will be
embedded.
You can then click
Save, and then
adjust any settings
that appear in an
additional dialog.
For example, if you
save the image as a
TIFF image, you’ll
be presented with
the TIFF Options
dialog. This allows
you to set options
for compression, for
example, in addition
When saving the final prepared image, it is important to ensure the profile is embedded as part of
to other settings.
the image, and that the file is saved based on the preferences of your commercial printer.
It is best to check
with the printer to
and recommendations about their preferred
determine the best settings, although in most
workflow for preparing the images for print,
cases it will be perfectly fine to use the LZW
including color management, optimization,
option for compression for TIFF images for
sharpening, and any other insights you can gain.
purposes of reducing the size of the
file you’re saving.
Printing images should be, in my view, a
collaborative process between the content
creator and the people who will work with
Knowledge and Communication
your images in various ways to produce the
If you’re going to be preparing images to be
printed result. You’ll get the best results with
printed by a commercial printer, I think there
a cooperative approach, an open dialog, and
is tremendous advantage to gaining as much
a willingness to listen and learn. Just don’t be
knowledge about the process as possible.
afraid to speak up for yourself too, in order
One of the best things you can to gain that
to ensure the printed result meets or exceeds
knowledge is to develop a good working
your expectations.
relationship with the printer. Get information
PIXOLOGY
19
Merging
Catalogs
Combining Multiple
Lightroom Catalogs
into a Single Master
Catalog
By Tim Grey
I’ve long advocated that
photographers using
Lightroom to manage
their photographic images
should utilize a single
catalog for all of their images.
In my mind, it simply makes more
sense to have all images accessible
in a single catalog, rather than having
a situation where you need to first figure
out which catalog contains the specific photos
you’re looking for at any given time.
Over time I’ve talked with more than a few
photographers who had created multiple
catalogs for one reason or another, but then
came to agree that my recommendation to
utilize a single catalog made sense. However,
they were then faced with the task of merging
their several catalogs into a single catalog
without losing any photos or information in
the process.
Presented here are the steps I recommend for
merging multiple Lightroom catalogs into a
single catalog containing all of your photos
and video clips.
PIXOLOGY
20
1 - Make a List
The key to avoiding problems when you
merge catalogs in Lightroom is to stay
organized during the process. Before getting
started, make a list of all catalogs that need
to be merged. If you have recently accessed
all of the catalogs you use, you can simply
choose File > Open Recent from the menu
in Lightroom and look at the list of recently
opened catalogs on the submenu. You may
also want to browse the Pictures folder
where the catalogs are created by default, and
check external hard drives and other storage
locations where you may have saved catalogs.
As you locate the various catalogs that
contain images you’d like to merge into a
single catalog, write down the name of each
catalog. If the catalogs are located in different
folders or on different drives, it can also be
helpful to specify the location for each catalog
on your list.
2 - Identify the Master Catalog
From the list of catalogs that you will
be merging, identify which catalog will
become the single catalog containing all of
your images. The choice may be obvious
if you already had a primary catalog that
contained most of your images, and then
several secondary catalogs containing other
images. In other cases the decision may be
Creating a list of all catalogs you want to merge, and
identifying the “master” catalog, can help you stay organized
in the process of merging your catalogs.
a bit more arbitrary, based on which catalog
is already in the best storage location, which
catalog has the most appropriate filename for
a master catalog, or other criteria. The key
is to pick a catalog as the destination of the
merge process, so you’ll know where to start.
I recommend marking this catalog as the
master on your list of catalogs to help avoid
any confusion later.
3 - Backup All Catalogs
While the process of merging catalogs is
relatively safe, it is still a good idea to make
sure you have a current backup of all catalogs
before you begin the process. This will
provide the ability to go back to the backedup version of the catalog if something should
go wrong that causes file corruption, for
example. But it also protects against the risk
of making a mistake during the process of
merging your catalogs.
To backup your catalogs, you can open each
catalog in turn in Lightroom, then choose
Edit > Catalog Settings on Windows or
Lightroom > Catalog Settings on Macintosh.
On the General page of the Catalog Settings
dialog, choose “When Lightroom next exits”
from the popup in the Backup section.
Close the Catalog Settings dialog, and then
close Lightroom to initiate the backup
process. When the backup is finished, launch
Lightroom again and repeat this process for
each of your other catalogs.
4 - Open the Master Catalog
Once you’ve identified which catalog will
become your master catalog, and thus the
destination for your merge operation, you
can open that catalog to get started with the
merge process. If you’ve recently worked
with this catalog, you can choose File > Open
PIXOLOGY
21
It is a good idea to backup all of your catalogs via the Catalog Settings dialog in Lightroom before you start the process of merging
your catalogs.
Recent from the menu in Lightroom, and
then select the catalog from the submenu.
You can also simply choose File > Open
Catalog from the menu and then navigate
to the location where the catalog is located,
select it, and click the Open button.
5 - Import from Secondary Catalog
The process of merging multiple catalogs is
really a process of importing data into your
master catalog. With the master catalog open,
go to the menu and choose File > Import
from Another Catalog. Refer to your list, and
navigate to the location of the first catalog
that needs to be merged. Select the catalog
file, which will have a filename extension of
“lrcat”. Then click the Choose button to bring
up the Import from Catalog dialog.
PIXOLOGY
By default, all images in the existing catalog
will be selected for import. In the New Photos
section, the default option will be to add
photos from the catalog being imported to
the master catalog you currently have open,
leaving the actual photos in their
current location.
If some of the images in the catalog being
imported are already included in the master
catalog, you’ll also be able to adjust the
settings for how those images are dealt
with. Hopefully this is not the case, as you
can create a variety of problems in terms of
organization if the same image is contained in
more than one catalog. If there are duplicates,
however, you will need to decide which
information should be kept. You can choose
the “Nothing” option from the Replace popup
22
if you want to keep all information
in the master catalog,
without updating based on the
information in the catalog you’re
importing from.
On the other hand, if the
information in the catalog being
imported from is more current, you
can replace the information in the
master catalog with the information
from the catalog you’re importing.
In this case you can choose whether
you want to replace metadata
and develop settings, or if you
want to replace metadata, develop
settings, and virtual copies. You
can also choose whether you want
to preserve the older settings as an
additional virtual copy. However,
The Import from Catalog dialog allows you to confirm the settings for the images
unless you’re not certain of which
being imported into your master catalog.
information is most current, I
recommend not creating this
all metadata and other details now included
additional virtual copy for all images that
in the master catalog.
are duplicative, as doing so can create
confusion due to multiple copies of images in
6 - Update the List
your catalog.
Once you’ve imported images from one of
In addition, you can choose to only replace
your secondary catalogs into the master
non-RAW images, (TIFF, PSD, and JPEG
catalog, you should update your list to reflect
files) so that, for example, only derivative
that. This will help ensure you don’t attempt
images will be replaced, while the RAW
to import from the same catalog more than
captures in your master catalog will
once, and perhaps more importantly that you
be preserved.
don’t inadvertently skip any of your catalogs
in the merge process.
Again, in most cases you should only have
“new” images being imported, as each
You can cross catalogs off your list as you make progress in
order to avoid any confusion as you merge your catalogs.
image should have only been imported into
a single catalog. Once you have established
the settings for the import, click the
Import button. The images will be added
to the master catalog, reflecting the folder
structure for the source images, and with
PIXOLOGY
23
It is a good idea to backup your newly merged master catalog as soon as the process of merging
is complete.
7 - Repeat Import for Other Catalogs
If you have more than two catalogs, meaning
more than one catalog needs to be imported
into your new master catalog, you will need
to repeat steps five and six above for each of
those additional catalogs.
8 - Backup the Merged Catalog
Once you have created your new master
catalog by importing information from your
secondary catalogs, it’s a good idea to make
a backup copy of the newly updated master
catalog. So, go back to the Catalog Settings
dialog by choosing Edit > Catalog Settings on
Windows or Lightroom > Catalog Settings
on Macintosh, go to the General page of the
dialog, and choose “When Lightroom exits
next” from the popup in the Backup section
at the bottom of the dialog. Then close
Lightroom and follow the prompt to backup
the catalog.
9 - Delete or Archive Extra Catalogs
With a single catalog that now features all
of your photos (and video clips), you have
one place to go to begin your search for a
particular image. To avoid confusion later,
PIXOLOGY
I recommend making all but your single
master catalog inaccessible. You could delete
all of the catalogs other than your master
catalog so they definitely can’t be accessed,
but I prefer to take a more cautious approach.
Therefore, I recommend moving the catalogs
to an archival location. This can be a backup
external hard drive, a specific folder setup
for this purpose, or some other location. The
key is to ensure that the catalogs you won’t be
using anymore aren’t easy to find, and thus
can’t be opened accidentally.
At this point I think you’re likely to find
that your images will be easier to find
because they are all contained in a single
catalog. You also may get the added benefit
of “discovering” images you would have
otherwise missed, now that there are more
folders and images represented in your
catalog. I realize that having “everything” in
one catalog may seem a bit overwhelming,
but if you utilize the various filtering options
that are available, I think you’ll find that the
advantages of working with a single catalog
far outweigh the disadvantages.
24
Noise Reduction
Strategies
By Tim Grey
Noise in digital photographs is often compared
to grain in film photographs, which certainly
makes sense in a very general way. After all,
each is related to exposure sensitivity in some
form. However, from an aesthetic perspective,
the two are quite different.
Film grain has a more organic quality to
it, providing texture to a photograph that
can be interesting. While it has always been
quite common for photographers to try to
minimize film grain with lower-speed films,
it was also not uncommon for photographers
to intentionally use high-speed film in order
to achieve the textured look that results. To
this day I remain grateful to my high school
photography teacher for encouraging me to
test out some very “fast” black and white film
(if memory serves, it was 3200 ISO film).
While I’ve periodically chosen to add some
luminance noise to an image in order to mimic
a film grain effect, and I’ve heard a handful of
photographers express that they like adding
noise—even color noise—to their images, it is
quite clear that most photographers prefer to
avoid noise completely whenever possible.
PIXOLOGY
What is Noise?
Noise is represented by random and relatively
significant variations in individual pixel
values. In other words, when you zoom
in closely on an image, instead of seeing
relatively even tones or smooth gradations
of tonal values, you’ll see what appears to be
completely random pixel values mixed among
the “real” pixel values in the photo.
Noise can be classified as either luminance
noise or color noise (also referred to as
chrominance noise). Luminance noise
involves variations in tonal values at the pixel
level, while color noise involves variations in
color values. Generally speaking color noise
is considered more problematic, but both are
typically regarded as having a negative effect
on overall image quality.
Noise is often described as being caused by the
use of a high ISO setting during capture. That
is certainly a significant cause of noise, due to
the amplification of the signals measured by
the image sensor that is performed when the
ISO is increased from the baseline value (100
ISO or 200 ISO for most cameras).
25
Noise is exhibited as random variations in tonal and pixel values in an image. Noise is generally most prevalent in dark areas of
an image, and almost universally regarded as a negative factor in terms of image quality.
PIXOLOGY
26
However, there are many other potential
causes of noise besides the amplification
triggered by a high ISO setting. These include
other forms of amplification applied to the
signal regardless of which ISO setting has
been selected, heat accumulation during long
exposures, and other factors.
Minimizing Noise at Capture
When I talk to photographers about the
issue of noise in digital photographs, one
of the first things I tend to bring up is the
critical need to understand your equipment.
Specifically, it is important to understand
how your camera responds to the various
factors that affect noise. When you know
what circumstances will lead to images with
an unacceptable level of noise, for example,
you’ll be much better equipped to make
decisions about minimizing noise in the
first place.
Noise is an unavoidable factor in digital
photography. Every image you capture will
have some degree of noise, regardless of
camera and capture settings. The question
is whether that noise will be evident in the
image, and if so, whether it will produce a
significantly negative impression of image
quality. That said, there are certainly ways
you can help minimize noise at the time
of capture.
The ISO setting is one of the most significant
factors under our control when it comes to
minimizing noise in your initial capture.
Therefore, one of the best things you can do to
prevent noise is minimize the ISO setting on
your camera. Of course, the ISO setting is one of
the three controls at your disposal—along with
lens aperture and shutter speed—for controlling
overall exposure. That means you’ll need to
balance the ISO setting with the aperture and
shutter speed to achieve the best overall result.
PIXOLOGY
The ISO setting you use for a given exposure is one of the
key factors affecting noise. Reducing the ISO setting to the
minimum possible value will help reduce noise.
It is worth noting that the larger your lens
aperture the more light you are making
available for the exposure, and therefore you
have the potential to reduce the ISO setting
more than would otherwise be possible. This
can be especially important when you are
already pushing your luck with a relatively
high ISO setting, and you’re willing to accept
less depth of field in order to avoid an even
higher ISO setting. In extreme cases you
may even want to opt for a lens with a larger
aperture size, even if that means utilizing a
lens with a shorter focal length and giving up
some depth of field, so you can reduce the
ISO setting and thus reduce the amount of
noise present in the capture.
It is an oversimplification, but you can think of
lens aperture as affecting depth of field, shutter
speed as affecting how motion in the scene is
rendered, and the ISO setting as affecting the
amount of noise that will be introduced to the
image. Whenever possible, use the minimum
ISO value, but not if doing so prevents you
from achieving adequate depth of field or a fast
enough shutter speed. Again, understanding
the behavior of your camera will greatly
inform the decisions you make about the
specific settings you should use.
27
Long exposures will also suffer from an
increase in noise, in large part due to the
heat buildup that occurs when the sensor
is active for a relatively long period of time.
Avoiding long exposures, especially those
over thirty seconds, enables you to reduce
the risk of long-exposure noise. Of course,
this also limits your creative options, so you
obviously won’t always be able to avoid long
exposures altogether.
However, whenever possible even for long
exposures you should try to employ a shutter
speed that is at least a little faster if you want
to minimize noise caused by long exposures.
This is why, for example, photographers will
often employ film for photographing star
trails, or will capture a series of shorter digital
exposures of star trail segments and then
blend the series of images together later using
Photoshop or other software.
If you will be capturing long exposures,
such as those over thirty seconds, you may
want to take advantage of the long exposure
noise reduction feature if your camera is
so equipped. When this option is enabled,
every time you capture an image with a
long exposure (generally a shutter speed
of thirty seconds or more), the camera will
actually capture two images. First, the actual
photograph will be captured. Then the
camera will automatically capture another
image with the same exposure settings,
but with the shutter closed during the full
duration of the exposure.
This “black frame” exposure will record the
noise signature of the camera under the
specific conditions of the situation, and the
camera will then subtract that noise from the
original capture. This will obviously double
the amount of time required to capture each
image, but it can also significantly reduce the
noise levels in the resulting photograph.
PIXOLOGY
If your camera is equipped with an option to apply long
exposure noise reduction, it is generally best to turn this
option on to help reduce noise with long exposures.
One of the primary reasons long exposures
suffer from increased noise is the buildup
of heat for the image sensor when it is
active for such an extended period. As you
can probably imagine, it can take time for
that heat to dissipate, and therefore if you
capture a series of images—especially a
series of long exposures—the noise levels
will get progressively worse from one
capture to the next.
It can therefore be helpful to allow your
camera to cool down a bit in between
exposures. This will allow the heat to
dissipate, leading to less noise in
subsequent captures.
Reducing Noise
When capture settings for the specific
digital camera lead to a level of noise
that you find unacceptable in terms of
overall image quality, you’ll naturally
want to apply some noise reduction
after the capture in order to improve the
overall appearance and quality of the
photo. Just as with capture settings to
begin with, noise reduction involves a
degree of compromise.
28
At a very basic level, noise reduction
involves a process of averaging out
pixel values. This is, to be sure, a gross
oversimplification, as there is considerable
sophistication involved in the noisereduction process. But if you think of noise
reduction as a process of simply averaging
out pixel values, you’ll be better able to
appreciate the problems that can be created
in the process of trying to improve an
image by reducing noise.
This is obviously a rather subjective issue,
and in situations where noise is significant it
can be a challenging compromise. The key is
to be aware of the effects of noise reduction
so you can look for those effects as you work
with the image, and make a more informed
decision about how much noise reduction
to apply.
The simplest method of averaging out pixel
values involves what is essentially just a
blurring of the image. In fact, for an extreme
look at blurring as a method of averaging out
pixel values, you can look at the Average blur
filter in Photoshop (Filter > Blur > Average).
This filter transforms an image into one
where every pixel is the exact same color, with
that color reflecting the average color of all
pixels. The result is obviously a complete loss
of detail in the image.
While different noise reduction software will
involve a different set of controls and thus
may call for a slightly different approach to
noise reduction, the general process tends
to be the same. You’ll typically find separate
controls for luminance noise reduction
versus color noise reduction. For each of
those you will find a control for adjusting the
strength of noise reduction, and additional
controls that provide methods to mitigate
the degree of detail lost in the image.
These mitigation controls typically include
adjustments for contrast, sharpening, and
detail retention, for example.
Noise reduction can be thought of as a
very mild version of the Average blur filter.
Through sophisticated methods, advanced
noise reduction algorithms analyze the image
and attempt to reduce the appearance of noise
while retaining image detail. But ultimately
there will still be some degree of compromise
involved with noise reduction. Specifically,
luminance noise reduction will result in a loss
of overall texture and detail in the photo, and
color noise reduction will result in a loss of
color detail and saturation in the image.
I recommend taking an approach that
involves first neutralizing all of the noise
reduction controls, including both the
actual noise reduction intensity control as
well as the controls for mitigating detail
loss. Then increase the strength of the noise
reduction control to achieve a reduction in
perceived noise within the image. At that
point you can utilize the various options for
improving the level of detail evident in the
image as a compensation for the negative
effect of noise reduction.
Because of the potential pitfalls inherent in
noise reduction, it is important that you not
apply more noise reduction than you need.
In general I recommend using the minimum
amount of noise reduction necessary to bring
the noise down to an acceptable level, without
causing new problems that are perhaps worse
than a little noise.
PIXOLOGY
29
A Typical Approach
To help illustrate the approach I
recommend for noise reduction, let’s take
a look at the controls available in Adobe
Camera Raw and the Develop module in
Adobe Photoshop Lightroom. Both of these
applications use the same code base for
RAW processing, so the exact same controls
are available.
The Noise Reduction controls are found in
the Detail section within both Adobe Camera
Raw and the Develop module in Lightroom.
The Luminance slider adjusts the strength
of luminance noise reduction and the Color
slider adjusts the strength of color noise
reduction. There are also Detail sliders for
both Luminance and Color, which control
the degree to which you want to recover
detail affected by noise reduction, as well as
a Contrast slider that enables you to increase
perceived sharpness and detail by enhancing
overall contrast.
I start by increasing the zoom setting to
around 4:1 (400%) or higher. While you
want to use a 1:1 (100%) zoom setting when
evaluating sharpening settings, for noise
reduction you want to be able to clearly see
the individual variations in pixel values when
applying noise reduction.
I’ll then reduce all of the slider values to their
minimum value of zero, all the way to the left.
This will effectively disable the full effect of
noise reduction for the image.
Next, the values for the Luminance and
Color sliders can be increased while carefully
evaluating the image to determine the best
setting. In most cases the color noise is the
The first thing I recommend when approaching noise reduction is to set all of the available controls to their minimum value,
essentially disabling any noise reduction so you can evaluate the image and your settings from that baseline.
PIXOLOGY
30
most problematic in an image, and so I start
with the Color slider and then move on to the
Luminance slider.
sharpening and noise reduction adjustments,
and then click the button again to see the
image with these adjustments applied.
Once I’m happy with the degree of noise
reduction being applied for both luminance
noise and color noise, I’ll generally toggle the
preview to see the before and after view of
the image. This can be very helpful in both
evaluating the effect of the noise reduction
already applied, as well as to evaluate the
degree of adjustment needed to mitigate
detail loss.
It is also a good idea to pan around the image,
examining various areas to see the effect of
noise reduction. For example, shadow areas
will tend to contain more noise than midtone
areas, but you may find more problematic
detail lost in highlights compared to other
areas of the photo.
In Adobe Camera Raw you can turn off the
Preview checkbox to see the image without
any adjustments applied, and then turn it
back on to see the image with all adjustments
applied. In Lightroom you can simply click
the switch button to the left of the Detail
header to turn off the effect of only the
With the strength of noise reduction set for
both luminance noise and color noise, I’ll
move on to mitigating the negative effects of
noise reduction. In most cases I find the loss
of detail caused by luminance noise reduction
is more problematic than the color changes
caused by color noise reduction, and so I’ll
first work with the Detail slider directly below
the Luminance slider, dragging it to the right
Color noise reduction should be applied at a minimum strength necessary to compensate for the noise without introducing new
problems in the image. Detail can then be recovered to some extent, compensating for the negative aspects of noise reduction.
PIXOLOGY
31
to the degree necessary to improve detail
without re-introducing noise. It can be very
helpful to increase the slider value significantly
at first to get a better sense of how the image
will respond, and then bring it back down to a
value that works best for the photo.
After adjusting the Detail slider for luminance
noise reduction, I’ll similarly increase the value for
the Detail slider for color noise reduction. Once
again, increasing the slider value significantly at
first can be helpful in evaluating the effect.
After I am happy with the setting established for
the two Detail sliders, I’ll adjust the Contrast slider
as needed to enhance overall contrast in the image,
helping to improve perceived detail.
After establishing values for all of these controls,
it can be helpful to further review various areas
of the image and fine-tune all of the settings as
needed to achieve the best balance between a
reduction of perceived noise and a retention of
overall detail in the image.
It is also worth noting that various other
adjustments can help improve the quality of the
image after applying noise reduction. For example,
the Clarity adjustment in Adobe Camera Raw or
Lightroom will improve overall midtone contrast,
which can help enhance overall perceived detail. In
addition, the Vibrance and Saturation sliders can be
used to increase the intensity of color in the image,
helping to compensate for the effect of color noise
reduction. And of course, sharpening can improve
the overall perceived detail in the image as well.
By understanding the various issues related to noise
reduction, you’ll be able to better avoid noise in the
first place, identify the effects of noise within your
images, and compensate for that noise with careful
attention to detail in the noise reduction software of
your choice.
After applying color noise reduction, luminance noise reduction can be applied. It is critical at this stage to pay careful attention
to detail and sharpness in the image, and to find the right compromise for noise reduction settings.
PIXOLOGY
32
Finding Celestial Bodies
A Free App for iOS Devices Provides a Clear Picture of the Sun, Moon, and Other Celestial Bodies
By Tim Grey
Every photographer, I’m sure, has heard the
mantra to “know thy subject” as it relates
to capturing great photographic images.
When it comes to sunrise and sunset, part
of the information you want to have is what
time the sun will make its entrance or exit.
That’s relatively easy information to find
from a wide variety of sources. In fact, in
most cases you don’t even need a source of
that information. The sunrise tomorrow
will typically be within just a few minutes of
today’s sunset, depending on how far from
the equator you are.
PIXOLOGY
33
But what if you want to include the moon
in the frame? That’s a little more difficult to
predict if you don’t have detailed information
about the patterns of the moon, both in
terms of the time of moonrise and moonset,
and in terms of the specific location of the
moonrise and moonset on a given date in a
particular location.
Things can be even trickier if you want to
photograph other celestial bodies, such as
centering a long exposure on the North Star
or including Venus in the frame. Fortunately,
there are a wide variety of sources of this type
of information, and one of the most useful
and easy to use sources of such information
I’ve found is an app for iOS devices
(the iPhone and iPad) called Planets from
Q Continuum.
magnetic north, so then can the Planets app
point you toward the sun, the moon, or other
celestial objects.
Planets also provides a “Visibility” feature,
which provides a clever visual indication of
the range of times that the sun, moon, and
planets will be in a position where they will
be visible if the conditions allow. The various
display options are available along the bottom
The Sky 2D view in the Planets app provides a fast reference
for the position of the sun and moon.
Planets Overview
Information is one thing, but information
presented in a way that enables it to be
used quickly and effectively is something
altogether different. And to me, this is
where the Planets app really shines. Rather
than presenting, for example, a simple table
showing the time of sunrise and sunset,
perhaps with a magnetic heading telling you
which direction to look at the appointed
hour, Planets provides a visual indication of
the information you really need to locate a
variety of celestial bodies.
For example, there are two-dimensional and
three-dimensional views that enable you to
quickly determine the current position of
the sun relative to you. The Planets app also
takes advantage of the information available
from the iPhone, based on the GPS receiver
and sensors that determine the direction the
phone is pointed, for example. Just as the
needle of a compass can point you toward
PIXOLOGY
34
of the Planets display, and a simple tap allows
you to switch between the various views.
Sky 2D View
The Sky 2D view provides a simple compass
display with the current position of the sun
and moon indicated. The direction around
the compass provides an indication of which
direction you would need to face in order to
find the sun or the moon, and the distance
from the edge of the circle indicates the
relative distance from the horizon.
than not it doesn’t tell you much that you
don’t already know. After all, the sun and the
moon aren’t all that difficult to locate when
they are above the horizon and free of clouds
or other obstructions.
The Sky 3D view, on the other hand, is
incredibly helpful in a wide variety of
situations, because it provides considerably
The Sky 3D view provides an impressive tool for locating
a wide variety of celestial objects relative to your current
position and the direction you’re facing.
You can also choose whether you want
to lock the compass so north is always at
the top of the display, or if you would like
the application to orient the compass to
automatically point in the correct direction.
You can toggle this option with the button at
the top-left of the Sky 2D display. With the
automatic orientation feature turned on, you
can simply hold the phone in your hand and
turn until the sun or moon appears at the top
of the display. At that point you are facing the
position of the sun or moon. The distance
from the edge of the compass circle then
indicates how far upward from the horizon
you need to look to actually see the sun or
moon, assuming of course that weather
conditions don’t obstruct visibility.
The Sky 2D view will also automatically flip
if you turn the phone upside-down. What
that means is that you can hold the phone
overhead, with the display pointed downward
toward you. This can make it a little easier to
determine the position of the sun or moon,
since the display more closely matches what
you will observe in the real world.
Sky 3D View
While the Sky 2D view is certainly
interesting, I think you’ll find that more often
PIXOLOGY
35
more information. It allows you, for example,
to determine exactly where the sun will
rise or set, or where to find specific celestial
bodies in the night sky.
To begin with, the Sky 3D view shows you
positions not just for the sun and the moon,
but also for the Milky Way as well as for a
variety of stars, including an indication of the
various constellations. Even better, all of those
celestial bodies are shown as what is basically
a map of the sky, so you can see the position
of celestial objects relative to each other.
The real power of the Sky 3D view comes not
just from the fact that it provides a map of
celestial objects, and not just because it can
automatically adjust based on your position
on Earth as well as the direction you are
currently facing, but also because it provides
in effect a simulation of what you can expect
to see if you look to the sky.
For example, if you are out well before sunrise
and want to be prepared to capture the sun
coming over the horizon, you can enable
Sky 3D view, hold your phone upright, and
turn until you locate the sun on the display.
The earth will be indicated by a translucent
green arc, so you can clearly see that the sun
is below the horizon, for example, and can
determine exactly where the sun will appear
when it rises. Even better, a dashed line
indicates the path the sun will follow, so you
can better anticipate exactly where the sun
will appear on the horizon.
As with the compass view, you can lock the
display so it remains fixed, or have the display
automatically adjust based on movement of
the iPhone. With the automatic movement
option enabled, the iPhone creates an
experience somewhat like wearing nightvision goggles or perhaps x-ray glasses. Even
when it is bright and sunny at the middle of
PIXOLOGY
the day, for example, you can use the Sky 3D view
to see exactly where all the constellations are.
I have found the Planets app to be incredibly
helpful for determining where the sun or the
moon will rise and set, what path the sun
will take across the sky so I can anticipate
potential compositions for including the sun
in the frame (as discussed in an article in
this issue), where I can locate the Milky Way,
and where the North Star is located so I can
center on it for star trail photography.
Visibility Information
The Sky 2D and Sky 3D displays provide
details about the location of various celestial
bodies, but not about when you can expect
those celestial objects to cross the horizon.
The Visibility display, however, provides
exactly that information in a format that is
easy to instantly interpret.
The sun and moon, as well as all of the planets
of our solar system, are listed. That does
mean that Pluto is not on the list, since it was
downgraded from official planet status, but
that’s not an issue for normal photography in
any event since it is not visible due to its
great distance.
All of these celestial objects include a display
that shows the duration of their visibility,
including the time they become visible above
the horizon and then become invisible behind
the horizon. In other words, you can see at a
glance when the sun will rise and set, when
the moon will rise and set, and when the
various planets will be within visible range
(above the horizon). Naturally you also need
to take into account the current weather and
daylight conditions, but the Visibility display
makes it easy to know which objects are
currently above the horizon.
36
You can then use the information on the
Visibility display in conjunction with the
Sky 3D (or Sky 2D) display to get a precise
indication of when various objects will be
visible, and where they can be found.
A Great Value
Having a great deal of information available is
one thing, but having a wealth of information
that you can quickly and easily interpret
is another thing altogether. I’ve found the
Planets app to be invaluable in this regard,
making the task of determining where and
when I can find specific objects in the sky a
remarkably simple task. What’s even more
remarkable is that this app is absolutely free.
If you’re an iPhone or iPad user, I highly
recommend installing the Planets app as
a useful tool for a variety of photographic
situations that involve celestial objects in
the frame.
You can find the Planets app online here:
http://bit.ly/planets_ios
Visibility view offers a quick reference of when the sun,
moon, and planets will be above the horizon, as well as the
times they will rise and set.
PIXOLOGY
37
Sketch Effect in Elements
A Guided Edit Option in Photoshop Elements that Enables a Fun Sketch Effect
By Tim Grey
Perhaps it is simply because I can’t draw
a picture to save my life, but I’ve always
found a sketch effect to be attractive for
certain photographic images. If you utilize
Photoshop Elements to optimize your
images, you can use a Guided Edit option
to apply a sketch effect with ease.
PIXOLOGY
38
1 Open an Image
The best images for a sketch effect tend to
be relatively simple images with a clearly
defined subject. Highly detailed images
with significant texture tend not to work as
well, because they tend to end up looking
cluttered. Find an image you think may be
interesting for this effect, and open it in the
Elements Editor.
2 Switch to Guided Edit Mode
Chances are you spend most of your time
in the Elements Editor working in Expert
mode, adding adjustment layers, cleaning
up blemishes, and performing other tasks
to optimize your images. The Guided Edit
mode enables you to perform a variety of
tasks—most of them creative effects—with
a step-by-step process. So, choose Guided
from the set of options at the top of the
Elements Editor to begin.
PIXOLOGY
39
3 Choose the Line Drawing Effect
When you switch to Guided Edit mode,
you’ll see a list of the Guided Edit options
along the right side of the Elements Editor.
Those options are divided into sections, and
you’ll find the Line Drawing option in the
Photo Effects section. Simply click the Line
Drawing option to bring up the instructions
for applying the effect to the current image.
PIXOLOGY
40
4 Apply the Pencil Sketch Effect
The first step of the Guided Edit for Line
Drawing is to apply the Pencil Sketch effect.
Simply click the button for step one to apply
the effect. The text associated with this button
indicates that clicking a second time will
intensify the effect. However, I find that with
the vast majority of images clicking a second
time actually tones down the effect, making
the lines less intense. Therefore I recommend
only clicking the button once.
PIXOLOGY
41
5 Reduce Opacity
Next, click the Adjust Layer Opacity button.
I think of this as merely providing a preview
of the general effect, since you’ll be able to
fine-tune the opacity for the effect later. But
for now, click this button once so you’ll have a
better sense of how the effect is working with
the current image.
PIXOLOGY
42
6 Return to Expert Mode
The next step in the Guided Edit is to apply
a Levels adjustment in order to add density
to the lines of the sketch effect. However, I
recommend applying this portion of the effect
manually, so that you have greater flexibility.
So simply click the Done button to complete
the Guided Edit process, and then choose the
Expert editing mode.
PIXOLOGY
43
7 Apply a Levels Adjustment
Instead of having the Guided Edit apply
a Levels adjustment directly to the sketch
effect, I recommend using an adjustment
layer so you can always fine-tune the result
later. Click on the Add Adjustment Layer
button (the half-black/half-white circle icon)
on the Layers panel and choose Levels from
the popup menu. On the Adjustments panel
(labeled Levels since you’re working with a
Levels adjustment at this point), click the Clip
to Layer button (the button at the bottomleft of the Adjustments panel). The Levels
adjustment layer will now only apply to the
sketch effect layer directly below it. Drag the
black point slider below the histogram display
toward the right to intensify the dark lines.
You may also want to drag the white point
slider toward the left to ensure the bright
areas remain white, and fine-tune the gray
(middle tone) slider as needed to complete
the effect.
PIXOLOGY
44
8 Adjust Layer Opacity
Click on the layer that was created by the
Guided Edit to produce the sketch effect (it
will be called Layer 1 by default), and then
adjust the Opacity for this layer using the
control at the top-right of the Layers panel.
This will allow you to adjust the degree to
which the underlying image is able to show
through the sketch effect. With a higher
Opacity value, very little color will show
through, and with a low Opacity value
the sketch effect will fade back and the
underlying image will appear
more prominently.
PIXOLOGY
45
9 Finalize and Save
With the basic sketch effect applied, you
can now fine-tune the image by refining
the Levels adjustment, altering the Opacity
setting for the sketch effect layer, and even
adding additional adjustments if you’d like.
When you’re finished, you can save the image
as a TIFF or PSD file so you can preserve
the layers, enabling you to make minor
adjustments later as needed.
PIXOLOGY
46
Fun
Sun
with the
Avoiding Common
Mistakes when
Including the Sun
in the Frame
By Tim Grey
Almost without fail, if I switch to a
wide-angle lens I’ll contemplate
including the sun in the frame,
provided the sky is relatively
clear and thus the sun is actually
available. The result can be
dramatic and interesting, but the
technique also involves some
unique challenges. Presented
here are tips for getting the best
images when you’ll be including
the sun in the frame.
PIXOLOGY
47
Clean the Lens
This is easily the tip I consider most
important when it comes to capturing images
with the sun in the frame. It is obviously best
to keep all your photographic equipment
clean and in good condition, but in most
cases a few spots on your lens aren’t really
an issue. Under normal circumstances any
spots on the lens will be rendered so far out of
focus relative to the scene that any evidence
of such spots in the photos you capture would
be highly unlikely.
However, when the lens is pointed toward the
sun, if you have blemishes caused by dust,
water droplets, or other contaminants, the
result will be incredibly obvious spots, flare,
or other artifacts in your photos.
Use an air blower to remove any significant
particles, and then use a lens cloth to clean away
any remaining contaminants such as water
stains. For more stubborn blemishes you can
utilize a product such as the LensPen (http://
amzn.to/102NNL1) to buff the spots away.
Remove Filters
If a filter is not necessary for the specific aim
of your photograph, it is best to remove that
filter from the lens. Otherwise, you are likely
to see at least some additional aberrations
in the image caused by reflections of light
between the individual filters and the lens.
Obviously if you need a particular filter
to achieve the result you’re after, such as a
neutral density filter in order to enable a
long enough exposure to provide motion
blur in the scene, you’ll need to make that
compromise. If the circumstances allow,
you may try slightly shifting the angle of the
PIXOLOGY
Even minor water spots or dust on the front lens element can
lead to significant problems in the image when the camera is
pointed at the sun, such as the bright spots seen in this image.
camera so that any reflected elements are
positioned in an area that they will be easier
to remove in post-processing. This may also
mean you’ll need to crop the image to
achieve the framing you intended, and in
some cases reframing simply won’t work for
your composition.
Most importantly, be aware that adding filters
to your lens will likely result in some degree
of optical reflections when you’re including
the sun in the frame. Remove filters you
don’t need, and otherwise evaluate your
captures to determine if there are problematic
aberrations you may be able to deal with at
the time of capture, saving yourself some
effort later in your workflow.
48
Mind the Weather
At times you may be inspired to include the
sun in the frame because of a brilliant blue
sky, or perhaps because of beautiful cumulus
cloud formations scattered across the sky.
At other times you may set out looking for
different opportunities. Whatever the case,
the sky conditions can have a significant
impact on the effect in your photos. Even a
very thin overcast, for example, can prevent
a sunburst effect. And of course a heavier
overcast can cause the sun to appear merely
as a slightly bright area in an otherwise
dark sky.
Familiarity with the typical weather trends
in the area you’ll be photographing can
With hazy or cloudy conditions, the sun will become a large
diffuse light in the frame, which can detract from the overall
image in some cases.
obviously be a tremendous help. But putting
a little effort into obtaining a detailed weather
forecast can pay significant dividends,
especially if you plan to incorporate the
weather into the photograph as well.
Time your Shots
If you have a particular shot in mind, timing
can be critical when the sun is involved.
Simply knowing what time you need to be
photographing in order to have the sun in a
particular location in the scene can be a huge
benefit. A variety of sources of information
can prove helpful in this regard. For example,
I often use apps for my iPhone such as Sunrise
& Set or Planets (covered in this issue) to
determine the current position and path of
the sun.
You may need to be sure to show up at a
particular location before the sun comes up,
before the sun disappears behind a building,
or before the sun set, for example, in order to
get the shot you’re after.
You may even need to choose a particular
time of year to photograph a given location,
so you can align the sun in a specific
position. I’m still waiting, for example, for my
schedule to coincide with an opportunity to
photograph the sun setting down the center
of 42nd Street in New York City, which only
occurs twice a year as the Earth makes its way
around the sun on a tilted axis.
Use Live View
I’m sure we’ve all been admonished since we
were kids not to look directly at the sun, and
this still holds true even when you’re looking
through the camera’s viewfinder. While it
is possible to look through the viewfinder
without looking directly at the sun in the
frame, and you could also temporarily place
PIXOLOGY
49
a moderately strong neutral density filter on
the lens to make a direct look possible, if your
camera offers a “live view” feature the process
is even easier.
By activating live view, you can compose the
scene and adjust exposure settings all while
reviewing the LCD on the back of your camera,
rather than putting your eyes at risk looking
through the viewfinder toward the sun.
Just keep in mind that by using the live view
feature of your camera, the mirror is no longer
protecting the image sensor from direct
exposure to the sun. It is possible for the sun
to cause some degree of damage to the image
sensor when projected directly onto the sensor
by your lens, so it is best to keep such direct
exposure to a minimum.
Go Wide
In some cases you’ll have no choice but to
opt for a relatively wide-angle lens in order to
include both your key subject and the sun in
the frame. However, even in situations where
you’re able to employ a relatively long lens
while still including the sun in the frame, you
may want to at least consider capturing some
images with a wider view.
Including the sun in the frame creates a
relatively dramatic scene to begin with, and
capturing a wider view of the scene can
add to that drama. The wide view provides
greater context for the scene, and will cause a
perspective shift where the sun exists within
an environment rather than being a key
subject. That’s not to say that a wide-angle
lens should always be employed when you
intend to include the sun in the frame, but it
is worth exploring as a possibility.
PIXOLOGY
Knowing the time of sunrise and sunset, or even better the
specific path across the sky for the sun, can be helpful. That
information can be obtained from a variety of smartphone
applications, among other sources.
50
When including the sun in the frame it is worth thinking about stopping down the lens to create a sunburst effect, though in
some cases it may seem a bit cliché.
Stop Down – Maybe
I’ll admit the effect is a bit of a cliché in
photography, but I’ll also admit that I tend to
enjoy having a sunburst effect in many cases
when I’m including the sun in the frame.
I suspect most photographers realize that the
sunburst effect, with rays of light extending
outward from the sun, can be created simply
by stopping down the lens. What you might
not be aware of is that you don’t have to
stop down all the way, or to a specific lens
aperture. Many photographers, for example,
will automatically stop the lens down to f/16
when they want to achieve a sunburst effect.
In fact, even just stopping down the lens a
little will often result in a sunburst effect. Even
better, you can achieve a different look for
PIXOLOGY
the sunburst at various aperture settings for
a given lens. The difference in sunburst effect
with a small change in aperture may be so
subtle as to be difficult to discern without a
side-by-side comparison. However, a relatively
significant change in aperture, such as by two
or three stops, can have a somewhat dramatic
impact on the appearance of the sunburst
effect. I find that in different situations, for
example, I prefer different aperture settings for
a given lens in order to achieve a different look
for the sunburst effect.
Accept Lens Flare
While unnecessary filters will likely lead to
optical reflections in your images, and thus
are generally best avoided, you can’t really
avoid lens flare when including the sun in the
frame. Flare is caused by the same basic issue
51
With the sun in (or near) the frame, lens flare will often be unavoidable, so you may need to simply accept it as part of the
overall effect unless you want to spend considerable time cleaning up the flare.
that leads to problems with additional filters.
The only difference is that lens flare comes
from internal elements in the lens rather than
additional accessory filters.
On a hazy day there may be enough
scattering of light that lens flare won’t be a
problem. In other cases you may be able to
adjust your position or the angle of the lens
to minimize lens flare or at least position it
within the frame in an area that will be easier
to resolve later. However, there will also be
times where you simply can’t do anything to
reduce or eliminate lens flare based on the
specific capture conditions.
When lens flare simply can’t be avoided, my
recommendation is to simply accept that flare
as a consequence of the type of image you’re
capturing. There are things you can do to
PIXOLOGY
tone down lens flare after the fact, or at least
change the color of the lens flare so it blends
in better with the surrounding image. But at
times you may just need to accept that lens
flare is a common and naturel side effect of
including the sun in the frame.
Consider HDR
By definition, including the sun in the frame
creates an environment where the dynamic range
of the scene is going to be relatively extreme. That
means detail will be lost in the sun, and quite
likely within the greater scene as well.
I typically prefer to have a relatively dramatic
degree of contrast in scenes where I’m
intentionally including the sun in the frame.
However, in some cases you may find that
you want to preserve more detail. In those
52
When the sun is in the frame, or reflected into the frame, you may want to consider the use of high dynamic range imaging in
order to retain more detail in the final image.
cases, high dynamic range (HDR) imaging
provides a potential solution.
You could take a quasi-HDR approach and
simply capture two exposures, one optimized
for the sky and one optimized for the
foreground scene. You could also capture
a series of exposures to be blended into a
complete HDR result. The point is that you
have options, and it is better to consider those
options at the time of capture, and perhaps
give HDR a try “just in case”, rather than risk
disappointment when it is too late.
Apply Exposure Compensation
It is natural to assume that with the sun in
the frame the scene will be perceived by the
camera’s meter as very bright, and thus the
exposure will be set relatively dark. That would
PIXOLOGY
certainly be true if you used spot metering
while pointed toward the sun, of course, but if
you are using evaluative metering, for example,
you’re quite likely to end up with an exposure
where the sun is completely blown out.
The point is that when the sun is included in
the frame the overall dynamic range of the
scene will obviously be quite extreme. Without
an extreme approach to high dynamic range,
you’re not going to end up with detail through
the entire scene, including the sun. But frankly,
there’s no need to retain detail within the sun to
begin with in most cases.
You need to make an initial decision about
what detail in the scene is most important,
since compromise is going to be involved on
account of the extreme depth of field. If you
want to include a sunburst effect, you’ll want
53
to at least ensure exposure settings that are dark
enough to retain enough detail for the individual
rays of the sunburst to be somewhat prominent.
There isn’t a firm rule about overall exposure in
this type of situation. In most cases I’m looking to
retain some level of detail in the sun and sky, and
so set an exposure that according to the meter will
be quite dark. In other cases the foreground detail
is more important, and I don’t mind a somewhat
significant loss of detail in the sun and sky.
The key is to be aware of how the camera’s
meter, based on your metering settings, is
going to interpret the scene, and to override the
recommended exposure settings as appropriate
to your specific goals.
Clean the Lens - Again
Artifacts and blemishes in the image really are a
big enough deal that you’ll want to check the front
of the lens for any dust, water droplets, or other
contaminants periodically. This is, perhaps, an
obvious issue when you’re photographing near a
waterfall, close to crashing surf, or when there is
some degree of rain. Because the lens will typically
be pointed at least slightly upward when you’re
including the sun in the frame, there is an elevated
risk of blemishes on the front lens element. So, just
as you checked the lens before getting started, you
should periodically check it again and clean it
as needed.
It is important to take into account the extreme contrast generally present when the sun is in the frame, and adjust your
exposure settings accordingly.
PIXOLOGY
54
Pixology
The Magazine for Photographers
Pixology magazine is published electronically on a monthly basis. For more information, visit
www.pixologymag.com
Copyright © 2013 by Tim Grey. All Rights Reserved.
To contact the publisher:
Tim Grey
328 8th Avenue #132
New York, NY 10001
www.timgrey.com
[email protected]
About Tim Grey
Tim Grey is regarded as one of the top educators in digital
photography and imaging, offering clear guidance on
complex subjects through his writing and speaking.
Tim has authored more than a dozen books and hundreds
of magazine articles on digital imaging for photographers,
and has produced over a dozen video training titles on a
wide variety of subjects. He publishes the Ask Tim Grey
email newsletter in addition to Pixology magazine. Tim
teaches through workshops, seminars, and appearances at
major events around the world.
For more information:
www.timgrey.com
Every attempt has been made throughout this magazine to distinguish proprietary trademarks from descriptive terms by following the
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The publisher has made best efforts to prepare this magazine, but makes no representation or warranties of any kind with regard to the
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Parting Shot