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Mini PDF book with 20 excellent color management tutorials
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Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Table of Content Our Team................................................................................................................................... 3
6 Simple Steps To Good Color Management .............................................................................. 5
Using ICC Profiles ....................................................................................................................... 6
Profile Your Monitor .................................................................................................................. 8
Photoshop Color Settings ......................................................................................................... 14
Softproofing............................................................................................................................. 15
Navigating The Epson Printer Driver With Photoshop............................................................... 19
Controlling Your Environment .................................................................................................. 24
Profile Your Printer .................................................................................................................. 28
Editing Spaces Compared ......................................................................................................... 31
Choose A Wide Gamut Editing Space ....................................................................................... 32
Benefits of Editing Images In 16 Bit Mode ................................................................................ 35
What To Do With Photoshop’s Color Management Dialogs ...................................................... 38
Rendering Intents Compared ................................................................................................... 43
Profile Your Printer .................................................................................................................. 46
Test Files .................................................................................................................................. 47
Managing Camera Profiles ....................................................................................................... 47
Using X-Rite’s Color Checker Passport – Target Or Profiles ....................................................... 48
Softproofing............................................................................................................................. 52
Review – ColorThink ................................................................................................................ 56
Review – SoLux Lighting ........................................................................................................... 60
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Our Team
At Caponigro Arts we're all photographers with our own creative lives and unique sensibilities, so it's
likely we not only speak your language but also share similar passions. We each have areas of
expertise.
John Paul Caponigro, CEO
John Paul delivers the content - images, writing, lectures, seminars, workshops, and consulting.
If you want to discuss obtaining customized content not found on this site ask for John Paul.
Arduina Caponigro, Sr. Technical Director
Ardie assists all in-house printing, teaches, and manages all internal systems (hardware, networks, software).
She loves all things technical, which you would never know by the dreamy, timeless quality of her personal work.
If you've got a technical question ask for Ardie.
View Arduina's website here: www.acaponigro.com
Charles Townsend Adams, Technical Director
Charles assists all in-studio workshops, manages both print and digital archives, and shares in-house printing with Ardie.
CT finds photographic inspiration along the Maine coastline and also works creatively in audio and video.
If you have a technical or creative question ask for CT.
View CT's website here: www.charlesadamsphoto.com
Diane Allia Walsh, Executive Director
Diane schedules the workshops, communicates with students and coordinates John Paul's lectures, seminars and
speaking events.
A lifelong artist and photographer, Diane now uses her photography as a resource in composition and reference for her
work in other media.
If you have any questions about workshops and scheduling ask for Diane.
We're also versatile, so if one team member isn't available, another may be able to help you.
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
We want to hear from you. You can contact any member of our team. Simply email their initials at
johnpaulcaponigro.com.
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
6 Simple Steps To Good Color Management
Color management is rocket science. But you don’t have to be a rocket scientist to drive the rocket.
Instead, be an astronaut. With a few simple steps you can achieve consistent, high quality color with
your images every time.
These are the six simple steps to good color management.
1 – Make Profiled Conversions
Assign an ICC profile to all image files either during Raw conversion or scanning. Use appropriate
profiles to make conversions into other color spaces with derivative files only. Minimize the number
of conversions made.
2 – Calibrate Your Monitor Using Hardware
Once a month, use a colorimeter to build an ICC profile for your monitor. Minimize the influence of
other light sources during characterization. Use the colorimeter’s software to help you set monitor
brightness between 90 and 100 and choose White Point D65 and Gamma 2.2. Check the results with
know target images afterwards.
3 – Set Good Photoshop Color Settings
In Photoshop’s Color Settings (in the Edit Menu) Set Color Management Policies to Preserve
Embedded Profiles and Ask When Opening / Pasting. And, choose a wide gamut device neutral
editing space. Start with North American Prepress Defaults and then change RGB to ProPhoto RGB.
4 – Softproof
Simulate the appearance of a print before printing. Go to View : Proof Setup : Custom and choose
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
the profile you intend to print with. Check Simulate Paper Color and choose a rendering intent of
either Perceptual or Relative Colorimetric. Make output specific adjustments before printing. Use
these adjust- ments only when printing these media.
5 – Navigate Your Printer Driver Correctly
Use Photoshop / Lightroom or your printer driver to manage color – not both. In general, favor using
Photoshop/Lightroom as this is the most versatile allowing you to use custom output profiles.
6 – Control Your Environment
Edit and evaluate your images in neutral surround- ings. Minimize the effect of extraneous light
sources, such as glare on monitors or backlighting. Evaluate proofs and prints in appropriate lighting.
There’s much more that can be said about each of these topics – but, not much more to do. Take
these steps and you’ll be well on your way to achieving consistent, high quality results with your
images.
Using ICC Profiles
ICC profiles define a meaning for the numbers used to represent colors in digital images. Without an
ICC profile digital files will produce unpredictable and inconsistent results.
As a rule, always use ICC profiles. There are a few rules for using ICC profiles. Always assign ICC
profiles (the correct ICC profile) when you create a digital file. Always use ICC profiles when
converting digital files from one color space to another. Never remove an ICC profile from a digital
file without replacing it. Use accurate high quality ICC profiles. While there are exceptions to these
rules, they’re rarely encountered.
Here’s one of the single most confusing things about color management. The same numbers in
different color spaces produce different colors. Why? Because while RGB color spaces (including the
standard device neutral editing spaces sRGB, Colormatch, Adobe 1998, ProPhoto) all use the same
Original posted by John Paul Caponigro at
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numbers from 0–255 to describe color, each color space is capable of different things. For instance,
wider gamut color spaces are able to represent more saturated colors. The numbers used to
produce the most saturated red (255/0/0) will produce a more saturated red in a wider gamut color
space than they will in a smaller gamut color space. So the same numbers in different color spaces
produce different results.
Here’s another way of saying the same thing: Change to stay the same. Use ICC profiles to define a
source and destination so you can change numbers precisely to make sure colors stay the same.
Once you know what numbers you need to produce the same color in two different color spaces
(like a monitor and a printer), you can precisely change the numbers to produce the same color
appearance as you move a digital image from one color space to another. If you don’t change the
numbers, the appearance of the colors will change when you move a digital image from one
device/color space to another.
Some change is inevitable when moving from a larger color space to a smaller gamut color space and
ICC profiles can be used to predict how color will change. They can be used to show you what must
change and can’t be restored (out of gamut colors) and what will change and can be restored (in
gamut colors). While you won’t gain color quality when converting from smaller gamut spaces to
larger gamut color spaces, you’ll lose a tiny bit of data, which if done a number of times can degrade
an image. So, keep color conversions to a minimum. (Optimally, convert once when you acquire an
image; a second temporary conversion will be made while you print an image).
Use ICC profiles. ICC profiles are recipes for color that clearly define numbers making color
consistent and predictable. They’re the foundation for working with color in digital imaging.
How important is this?
See what can happen below if you don’t use ICC profiles correctly.
If correctly used sRGB and ProPhoto can both represent this image accurately.
If incorrectly assigned the same profiles will distort the color of the image.
Original posted by John Paul Caponigro at
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Profile Your Monitor
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
If you want to display your images accurately, and make sophisticated decisions about how they will
or could look, calibrate your monitor with hardware. Monitor calibration is a must. It’s not optional.
It is easy. You need a device to do it well.
The visual comparator method (using your eyes to approximate an appearance on screen) is too
fraught with inaccuracies and inconsistencies to be relied on. Instead, use consistent, accurate,
objective hardware and software. Colorimeters don’t have favorite and least favorite colors, don’t
have color deficiencies, don’t get fatigued, don’t drink caffeine or eat sugar, don’t change over time
Original posted by John Paul Caponigro at
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or adapt to their environments, and don’t have emotions. You do. All of these can affect your
perception of color at one time or another. Colorimeters are in a stable state. You’re not. So when it
comes to making sure that your monitor displays color as accurately as possible, use a colorimeter.
While some colorimeters, and the software packages that ship with them, are better than others,
most colorimeters are good. Unless it’s defective, any colorimeter is better than none.
Spectrophotometers can also be use to calibrate monitors. What’s the difference between the two?
Unlike a colorimeter, a spectrophotometer has it’s own light source that can be used to make printer
profiles. Spectrophotometers can do more. They also cost more.
There is a difference between calibrating and characterizing devices. Calibrating a device is changing
its state, like setting the brightness of a monitor. Characterizing a device is measuring and mapping
the color capacity of a device or building an ICC profile to describe it. Most of the process of monitor
‘calibration’ is actually ‘characterization’.
Calibrating and characterizing your monitor is a simple process. Use the profiling device and
software of your choice. (I personally use X-Rite products.)
Take these steps.
First, set the brightness of your monitor. Use your monitor’s buttons or onscreen menu. The
software you use should help you confirm that you have set the brightness to a target range
between 90 and 100 lumens. If you monitor is brighter than this target range, it will be more difficult
to predict what your image will look like in print and it’s likely your prints will appear too dark. If it is
darker than this target range, your whites will appear too dull and you may not see subtle shadow
detail that exists in your files.
Second, indicate your gamma and white point preferences with your software. Specify a Gamma
2.2 and a white point of D-65. Both of these items produce confusion for many. The gamma is
specified based on the operating system of your computer, now the same for both Mac and PC. It is
not the gamma of your editing space, monitor, or output device. The white point is specified to
simulate a clean white, neither too blue and bright nor too yellow and dull. While the industry
standard for building ICC printer profiles and viewing prints is D-50 or 5000K, if you specify this
setting during monitor calibration, more often than not your whites will appear to dull and yellow.
This is due to monitor hardware limitations; their white points are so high, well above 7500K, that
when you simulate a white point lower than 6500K the monitor’s response starts to physically fail. A
white point of D-65 is a simulation that generates a standard preferred appearance – or a good clean
white.
Third, measure the color space and build the profile. All you have to do is click go and let the
software do the rest. To find a monitor’s capacity/limitations, the measurement software will send
known values to the monitor and its accompanying hardware will measure the monitor’s response.
With the before and after data it will generate an ICC profile that maps the color space of the
monitor. At the end of the process, make sure the title for the resulting ICC profile contains the date.
This profile will be loaded automatically whenever you restart your computer, until you build a new
one.
Original posted by John Paul Caponigro at
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Finally, confirm monitor calibration. View both synthetic test files (You can find many on my
website.) and real world images (Bill Atkinson provides and excellent evaluation file on his website.).
If grayscale ramps contain color casts or crosses, repeat the process.
Repeat this process monthly or when conditions change substantially.
Note, the purpose of monitor calibration is to get a monitor to display digital image files as
accurately as possible. The ICC profile will help your monitor display files better but it won’t change
them. Only changing the file’s ICC profile (so the numbers in your file mean something different) or
editing the file with software (so the numbers actually change) can do that.
Some of your files may contain colors that are out-of-gamut or too saturated for your monitor to
display. The best monitors today can display a gamut equivalent to Adobe RGB 1998 but cannot yet
display the full gamut of ProPhoto. This means that some of your files may be able to print colors
that are more saturated than your display. Do build your files in ProPhoto to take full advantage of
the capabilities of today’s printers and tomorrow monitors. As monitor technology evolves this will
become a less frequent occurrence.
One of the advantages of calibrating your monitors to a device neutral standard is that when
properly calibrated, all monitors, old or new, should generate very similar if not identical
appearances with the same files. You will not have to adjust your files when you look them on other
monitors, for instance when you replace your old monitor.
The purpose of monitor calibration is not to match a print, though it will help you make all your
prints more accurate. A well-calibrated monitor will help you predict what your images will look like
when printed, even on multiple substrates. This is what softproofing in Photoshop is designed to
achieve.
The value of the time and money invested in calibrating and characterizing your monitor simply can’t
be over stated. Once you’ve made this investment, you’ll reap countless dividends. You’ll get more
enjoyment out of the process and your images.
Here are the steps to take using X-Rite’s i1Profiler software.
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
On the Mac, ICC profiles are automatically stored in the ColorSync folder.
On the Mac, you can manually specify the monitor profile used by going to System Preference,
Display, Color and selecting a preferred profile.
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Photoshop Color Settings
Excellent Photoshop Color Settings can be set up in a few seconds.
Original posted by John Paul Caponigro at
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1 Go to Photoshop’s Edit Menu select Color Settings.
2 Start with Settings of North American Prepress 2 and then change RGB to ProPhoto RGB.
(Optionally change Gray to Gray Gamma 1.8.)
3 Click OK.
Here’s a little more about the underlying assumptions of this recommendation.
1. Choose a device neutral wide gamut editing space to create your images in. Wide gamut editing
spaces can contain all the data your camera or scanner delivers. Smaller gamut editing spaces may
not. Preserve your high quality information. ProPhoto is today’s preferred wide gamut RGB editing
space. It’s the only default that can contain all the colors your camera can capture.
2. Minimize the number of color conversions applied to your files. Set Photoshop to Preserve
Embedded Profiles. Always keep your master file in the color space it was created in. Convert only
derivative files.
3. Make sure you know about all the color conversions your file goes through. Set Photoshop to alert
you whenever a color conversion may take place. Check Ask When Opening / Pasting with Profile
Mismatches and Missing Profiles.
Standardize your workflow, using these settings for all your work (with few exceptions).
Softproofing
As a rule, always softproof an image to determine a rendering intent and make printer/substrate
specific adjustments to a image file before printing it.
You can get Photoshop to display an image the way it will appear when it’s printed, before you print
it, by softproofing an image. If you softproof before you print, you’ll get your best first proof or
maybe even a finished print. Not to be confused with a hard proof or physically printed piece, a
softproof uses an ICC profile to create an onscreen simulation of an image as it will appear when
printed.
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Wait. Haven’t you already done this by calibrating and characterizing your monitor with a
colorimeter, choosing an editing space along with color management policies in Photoshop, and
specifying the right profile for a printer/paper combination with your printer driver? Almost. Doing
these things ensures that all of the different color behaviors of the devices you’re using are
accurately described and that color conversions are handled precisely, but it doesn’t ensure that you
will see exactly how an image will look when printed. Without softproofing, you see how an image
looks on a monitor. To see an image on a monitor with the appearance of how it will look when
printed, before you print it, you need to take the final step of softproofing the image. This simulation
won’t change your file, just it’s appearance. Once softproofed, if you choose to, you can make
output specific adjustments to your file before printing to get a better first print.
How To Softproof
To softproof an image go to View: Proof Set Up: Custom and choose the ICC profile that describes a
particular substrate on a particular printer. Photoshop uses the selected ICC profile to simulate the
appearance of the final print.
It is essential that you specify the correct ICC profile and that the profile be accurate. The default
profile for Proof Set Up characterizes a standard web offset press. If you’re printing to another
device, to get an accurate preview, you need to specify a profile that accurately describes its
behavior. The softproof is only as good as the profile used. A bad printer profile will give you a bad
softproof and a bad print. If you find a profile doesn’t make a good softproof or print, use a better
printer profile.
Choose A Rendering Intent
Always softproof an image before printing so that you can choose a rendering intent. Your choice of
rendering intent will have a significant impact on print quality. Rendering intents are methods of
gamut compression, or how out-of-gamut values are treated relative to in-gamut values. Your choice
of four rendering intents can be simplified to two. Forget about Saturation, which is useful for bold
graphics but causes color distortions in continuous tone images. Forget about Absolute Colorimetric,
which is useful for cross-rendering or simulating the behavior of another device, like making a proof
of an offset press – it won’t deliver the best quality a printer is capable of. Use Perceptual to
maintain saturation, very often the side effect is that the image is lightened somewhat. Use Relative
Colorimetric to maintain tonal relationships, very often some saturation is sacrificed. This is one case
where exceptions prove the rule. Always compare these two rendering intents when you softproof.
Pick the rendering intent that gives you the view you like the most.
Original posted by John Paul Caponigro at
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Simulate Ink Black and Paper White
Checking the Simulate Paper White and Ink Black options is advisable. Because a monitor is capable
of displaying a brighter white and a darker black than a print, one dulls the whites (Simulate Paper
White) and the other dulls the blacks (Ink Black). Activating these features will not make the image
look better but it will make the preview more accurately match the print. In my opinion, the preview
generated using these features is aggressive, it moves the image in the right direction but it often
takes it a little too far. So, I use these options to frame reasonable expectations but I don’t rely on
them when making corrections to a file.
Check Black Point Compensation
Use Black Point Compensation. If you don’t, detail in shadows may be clipped and lose separation.
Viewing Light Temperature
The light you view your prints under is important. Printer profiles are generated for specific light
temperatures. Typically profiles are generated for viewing under a light temperature of 5000K. The
softproof will not be as accurate as it can be if you view the print under another light temperature. If
you want to make prints for other light temperatures, such as warmer lights like halogen or
tungsten, use a profile optimized for those light temperatures. Alternately, use a 5000K profile, but
expect the print to appear warmer than anticipated when viewed under a warmer light. You can
make appropriate compensations to your image by color adjusting your file to a slightly cooler color
(cyan/blue).
Compare Two Views At Once
It’s helpful to see a file both before and after it has been softproofed simultaneously. To do this, look
at two versions of the same file simultaneously. First, softproof the file. Second, duplicate the file
(Image: Duplicate); the duplicate will not be softproofed. Comparing the two versions will help you
see how your image will change when printed and how to compensate for these changes with
additional output specific adjustments.
Make Output Specific Adjustments
Original posted by John Paul Caponigro at
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Softproofing does not change the file, it simply previews how the appearance of an image will
change when printed. Once you see how an image will change when printed, you may decide to
adjust the file to compensate for those changes, before printing. You can make a printer/paper
specific set of corrections, while a file is being softproofed. Start by making a new Group with the
printer/paper combination included in the title. Then create a set of adjustment layers to make the
softproofed image match the unsoftproofed image as closely as possible. Typically, midtone contrast
is added with Curves (to compensate for dynamic range compression) and Hue/Saturation is used to
boost the saturation of in-gamut colors (to compensate for gamut compression). Use these
corrections for printing to that specific output condition (printer/ink/paper/profile) only. Turn the
layer set off for all other uses of the image.
Pick Your Battles
Pick your battles. Out-of-gamut means unprintable.
Don’t try to get a blacker black or a whiter white by further adjusting your file’s black points and
white points. If an image’s black points and white points were already set precisely, all you’ll succeed
in doing is clipping detail. Instead, accept the limitations of ink on paper and compensate with
midtone contrast. Alternately, use a paper that can generate a blacker black, for instance switch
from a matte to a glossy surface.
If an image contains out-of-gamut color that is too saturated for a device to print don’t try to
increase the saturation of the image to make them more saturated. You’ll run the risk of
oversaturating in-gamut or printable colors. Instead, accept those limitations and target increases in
saturation to in-gamut colors only; they too may be affected by gamut compression and you can
take steps to prevent this. You can see which colors are out-of-gamut by dramatically increasing
Original posted by John Paul Caponigro at
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saturation while an image is being softproofed; the colors that change are in-gamut while the colors
that don’t change are out-of-gamut.
Ignore Photoshop’s Gamut Warning. It often doesn’t indicate what’s out of gamut accurately, often
it’s far too conservative, and it can’t show you where the in-gamut colors that are affected are.
Mindful of these limitations, use any means at your disposal to make the softproofed image match
the unsoftproofed image as closely as possible.
It’s inevitable that an image will undergo changes when printed; sometimes a little and sometimes a
lot. Always softproof an image before you print so that you can frame reasonable expectations,
determine a rendering intent, identify how an image will be affected by gamut-compression, and
make corresponding output specific adjustments.
How accurate can a softproof be? Extremely accurate. Glass transmitting light will always look
different than paper absorbing light. However, you can get one to closely simulate the appearance
of the other. Softproofing will save you time, materials, and money. Softproofing will help you get
better prints.
Navigating The Epson Printer Driver With Photoshop
Successfully managing color for digital printing requires that the color in an image file be converted
from its device neutral color space to a device specific color space. (Typically this occurs by
converting from Adobe RGB 1998 or Pro Photo RGB to a device specific color space defined by an
ICC profile characterizing a specific combination of printer, ink, paper, and driver.)
Using Photoshop, you can either convert color in an image before you send it to a printer driver or
after you send it to a printer driver.
Choose one method of color management – not two. Easily made, a classic mistake is using both.
Double color management typically results in a print that is too light and magenta.
The Epson printer driver provides many ways to manage color conversions and get reasonably good
color. Two methods offer the best results; the Photoshop route and the Epson route.
Original posted by John Paul Caponigro at
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How do you do you choose either of these methods?
Let Photoshop’s Print window (under Color Handling) guide you – Let Photoshop Determine Colors
and Let Printer Determine Colors. (While the principle is the same for most printers, interfaces will
vary. Here’s information for the most current Epson interface.)
If you choose Let Photoshop Determine Colors under Color Handling, select a profile for Photoshop
to make the conversion with (a paper/ink/driver specific profile not the interface default of Working
RGB) under Printer Profile, choose a Rendering Intent of either Relative Colorimetric or Perceptual,
and then click Print Settings. In the Print window choose the correct Printer and then change Copies
and Pages to Print Settings. Select the correct Media Type, uncheck High Speed, and choose the
highest printer resolution available. Finally change Print Settings to Color Management and select
Off (No Color Adjustment). The Photoshop route turns Photoshop’s color conversion on and turns
the printer’s color conversion off.
The Photoshop route tends to hold slightly more saturation but it’s rendition of neutral colors and
gray balance is usually not as good as the Epson route. The Photoshop route is the route to take
when you want to use a custom profile. Use it if you are printing with either third party inks or
papers which require the use a custom profile to accurately describe the behavior of the alternate
media.
If you choose Let Printer Determine Colors under Color Handling, choose a Rendering Intent of either
Relative Colorimetric or Perceptual, and then click Print Settings. In the Print window choose the
correct Printer. Change Copies and Pages to Print Settings to select the correct Media Type, uncheck
High Speed, and choose the highest printer resolution available. Finally change Print Settings to
Color Management , choose EPSON Standard (sRGB) under Mode, and select Color Controls. The
Epson route turns Photoshop’s color conversion off and turns the printer’s color conversion on.
The Epson route tends to deliver significantly improved rendition of neutral colors and gray balance
with slightly less saturation. Try it when printing neutral colors. Use the Epson driver’s Advanced
B&W Photo feature for black and white images.
Each route works well. Each route yields slightly different results. Test them to see the differences.
(Note that you cannot see the differences between printing routes when softproofing; you have to
make physical proofs to see these differences. They can significant.)
The Photoshop Route.
1 Choose Print. Select Let Photoshop Determine Colors under Color Handling. Choose the profile you
want to print with under Printer Profile. Choose a rendering intent (typically Perceptual or Relative
Colorimetric). Check Black Point Compensation Click Print Settings.
2 Under Printer select the printer of your choice.
3 Change Copies & Pages to Print Settings. Select the appropriate or nearest Media Type. Select
Color under Color. Check Advanced. Uncheck High Speed.
Choose the highest printer resolution available under Print Quality.
4 Change Print Settings to Color Management and check Off (No Color Adjustment).
Original posted by John Paul Caponigro at
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The Epson Route.
1 Choose Print. Select Let Printer Determine Colors under Color Handling. Choose a rendering intent
(typically Perceptual or Relative Colorimetric). Check Black Point Compensation. Click Print Settings.
2 Under Printer select the printer of your choice.
Original posted by John Paul Caponigro at
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3 Change Copies & Pages to Print Settings. Select the appropriate or nearest Media Type. Select
Color under Color. Check Advanced. Uncheck High Speed. Choose the highest printer resolution
available under Print Quality.
4 Change Print Settings to Color Management and check Color Controls.
The Epson Advanced B&W Photo Route
Original posted by John Paul Caponigro at
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1 Choose Print. Select Let Printer Determine Colors under Color Handling. Choose a rendering intent
(typically Perceptual or Relative Colorimetric). Check Black Point Compensation. Click Print Settings.
2 Under Printer select the printer of your choice.
3 Change Copies & Pages to Print Settings. Select the appropriate or nearest Media Type. Select
Advanced B&W Photo under Color. Check Advanced. Uncheck High Speed. Choose the highest
printer resolution available under Print Quality.
4 Change Print Settings to Color Management and under Tone choose Normal. Optionally, use the
color wheel to tint the image.
Original posted by John Paul Caponigro at
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Controlling Your Environment
Original posted by John Paul Caponigro at
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One critical aspect of color management has nothing to do with either hardware or software. It’s the
environment you work in. Control your environment and you’ll control the color you see. Desktop,
walls, decorations, fashion, viewing light, secondary light sources, ambient light – it all matters.
Keep It Neutral
Color influences color. This is sometime physical, when filtered or reflected color alters the
appearance of another. This is always perceptual, when our eyes adapt to the presence of multiple
colors. That’s right. Surround one color with another color and you’ll experience the color
differently. You can’t measure this change in the physical world because the change takes place
inside your eye/brain. Simultaneous contrast is a perceptual adaptation that you can’t turn off, but
you can be aware that it’s happening, understand how it’s influencing you, and minimize it’s effects.
How? Surround yourself with neutral colors; they influence our experience of other colors least.
Neutral colors produce the least contamination and the least adaptation. And, medium gray values
produce the least brightness compensations of all neutral colors.
You may be tempted to make the appearance of your computer desktop colorful and lively. That’s
fine for many non-color-critical tasks. However, when you’re adjusting color, make your desktop
neutral. You won’t be able to see the color you’re adjusting accurately unless you do. If you don’t
want to change your desktop use Full Screen mode, to hide the desktop and surround your image
with a neutral color. (One downside to this is you’ll only be able to view one image at a time.)
Walls and decorations of any significant area should be neutral in appearance too. Make walls and
decorations neutral. For the purposes of controlling your environment, any neutral color is better
than a saturated color. You could opt for white, gray, or black. Don’t opt for designer whites, grays,
or blacks, which contain trace amounts of hue and saturation that can still influence your perception
enough to be significant. Choose neutrals. (If you’ve got a favorite image (poster, photograph,
painting, etc) that’s colorful, position it out of your field of vision while you’re adjusting color.)
Don’t forget fashion. Wear neutral colors. If you wear bright colors, they’ll influence your perception
too, especially if light reflects off of them and onto your surroundings or images.
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Light It Well
The most important thing to control in your environment is light.
After all, light is what produces your sensation of color.
Viewing light, secondary light sources, ambient light
It stands to reason, for viewing color accurately, you want white light not filtered or colored light.
(Don’t wear sunglasses or tinted glasses when adjusting color.) But what many people don’t consider
is that not all white lights are created equally.
You’ll want to consider the amount of light – measured lux. It’s better to have too much light than
too little light; colors will appear dull if you don’t use enough light; just don’t produce glare or make
viewers squint. A CRI of 90 or higher is recommended.
Next, consider the color temperature of light – measured in Kelvin degrees. While 5000K is the
industry standard (most viewing boxes and printer profiles are built for the 5000 K standard), in real
world situations very few people view printed color under 5000K light. More typically, prints are
viewed in galleries and museums in some form of halogen (3300K – 3800K) or in homes under
tungsten (2800K) with a mix of daylight which varies with time of day, weather, and season. Viewing
light for the end user is often highly variable. So, what do you do? Make prints for a specific lighting
condition if practical. Otherwise, standardize on a viewing light temperature that can be least
adversely affected in as many real world situations as possible. More people prefer the taste of
3600K than any other light temperature.
Finally, consider a light’s spectral distribution – smooth or spiky when graphed. White light can be
mixed with different combinations of colored lights. This rarely affects the appearance of neutral
colors, but it may have a significant affect on saturated colors. Light sources that contain only a few
spectral frequencies (spiky or limited) will increase the apparent saturation of the colors they
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contain and decrease the apparent saturation of the colors they don’t. Light sources that contain all
spectral frequencies (smooth or full) will render all colors without bias and won’t produce relative
saturation distortions. Full spectrum light (sunshine, tungsten, some halogen) makes colors appear
clearer and more saturated. (See my free ebook review on Solux lighting at
www.johnpaulcaponigro.com.)
Secondary light sources should also be considered. Avoid backlighting; don’t position your monitor
or proofs/prints with bright light sources behind them. Eliminate reflections; use blinds for windows
and reposition lights that reflect off monitors. Reduce glare and flare as much as possible. New
colorimeters (like Ax-Rite’s i1Display Pro and ColorMunki Display) compensate for these factors
during monitor calibration and constantly measure and adapt to changes in these factors over time.
Make your viewing experience as easy as possible. If you’re serious about color, you’ll plan to look a
lot.
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With a few careful choices you can make sure your environment supports your efforts to see and
adjust color precisely everyday. It’s time well spent. Without this attention to detail, even the most
sophisticated color-management systems may be compromised. With this attention to detail, you
can rest assured that you’ve done everything physically possible to control color. In a controlled
environment, your color will truly shine.
Profile Your Printer
Prints made with default (left) and custom (right) profiles compared.
Good printer profiles help make good prints. Better printer profiles help make better prints. So,
logically, you’ll want to use the best printer profiles to help you make the best prints.
How do high quality printer profiles contribute to print quality? A good printer profile helps render
optimum shadow and highlight detail, gradation, neutrality and graybalance, as well as color
rendition and saturation. (Remember, printer profiles characterize the combination of a printer’s
hardware, ink, media setting, and the substrate you choose. You’ll need different profiles for
different substrates on the same printer.)
How can you get good printer profiles? Look to three primary sources. One, use profiles provided by
printer manufacturers; they’re free. Two, hire a printer profiling service; profiles cost approximately
$100 each. Three, make printer profiles yourself; printer profiling systems run between $400 and
$1000. (Profiles supplied by substrate manufacturers are of uneven quality; a few are good, many
are bad.)
Which solution is right for you? It depends on both your printing conditions and needs.
If you’re using substrates supported by the manufacturer of your printer, try using the profiles they
provide first; they’re often quite good. Years ago, Epson raised the bar on the quality of printer
profiles provided by manufacturers. The highly sophisticated routines they use to produce their
printer profiles processed by supercomputers are truly state-of-the-art. It’s arguable that you can
produce better profiles, even with the most sophisticated profiling solutions available. Their profiling
routines factor in subtleties like dot structure or screening frequency. One of the reasons a solution
like this works is because the technologies and manufacturing standards they use are so consistent
that the unit to unit variation between individual printers of the same model is extremely low. (It’s
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less than a Delta E of 1 or the minimum variation the human eye can detect.) Some, printer
manufacturers, like Canon, provide a large number of profiles for substrates made by other
companies; their quality is generally quite high with only a few exceptions. Other printer
manufacturers, like HP, produce self-profiling printers. They need to be self-profiling, as the state of
the printer is constantly changing; when nozzles clog, new nozzles come on line; when ink cartridges
are swapped nozzles are replaced. One advantage to a system like this is you can quickly profile a
new substrate on a printer with no additional equipment. The quality of the profiles is often good,
but there will be times where you’ll want to improve upon it.
No manufacturer provides a comprehensive set of profiles that will cover the entire spectrum of
fast-evolving substrate industry. A little experimentation with new media is advised, sometimes a
lot. If you experiment with many medias or use more exotic substrates, you’d be well advised to
have someone make custom profiles for you or do it yourself.
If you’re using only one or two substrates not supported by the manufacturer of your printer, hire a
profiling service to make a printer profile for you. Profiling services are easy to work with. (Try
Chromix.com or Digitaldog.net.) You’ll download a profiling target from their website, print it, send
the print to them for measurement and profile building, and then they’ll email you the profile. When
you do this, make sure you don’t color manage the target file when you open it (Printer targets
should be without an ICC profile or “Untagged”; don’t assign one.) or when you print the target.
(Don’t use Photoshop CS5 for this, as it’s impossible not to manage the color when printing. Instead,
use the free utility Adobe provides on Adobe Labs. Or, use a previous version. Or, use any version of
Lightroom.)
IT8 targets are used to measure printer response during profiling.
If you use many third-party and / or exotic substrates and like to experiment with new ones
frequently, invest in your own profiling system – a good one. (I use X-Rite’s iOne Photo Pro.) The
process of making printer profiles isn’t difficult anymore. Today, you can perform fairly sophisticated
tasks quite easily. (See my website for step-by-step text and videos on how to do this.)
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Now, there are two other reasons to consider making your own profiles; viewing light specific
profiles and image specific profiles. Both of these types of profiles have become much easier to
make with recent upgrades to X-Rite’s i1 solutions. (I anticipate that other manufacturer’s offerings
following this trend.)
Light temperature specific profiles factor in the viewing light prints you make will be viewed in, both
the light’s color temperature and spectral distribution. To date, the vast majority of manufacturers
provide printer profiles optimized for the 5000K viewing standard only. Real world viewing
conditions are rarely 5000K. They vary, sometimes dramatically. Most galleries and museums use a
warmer light temperature, typically some form of halogen lighting, varying in color temperature
between 3300K and 3800K, at least they’re usually smooth spectrum light sources. (See my website
for more on this.) If you make your prints with 5000K profiles and view them under 5000K light, your
prints will appear warmer when they are displayed under warmer light. Optimize your prints for the
light they will be finally viewed under. If you don’t know what that viewing condition will be, adopt a
real world standard that will satisfy the largest number of display conditions possible; 3600K is a
good average and a light temperature that a majority of people find most pleasing.
Image specific profiles can be used to more accurately reproduce hard to render colors, such as very
dark or very light saturated colors. Printer profiles are built to accurately render the greatest number
of colors possible, but some sacrifices are always necessary. No one profile will be able to render the
entire spectrum equally accurately. To build image specific profiles, both the general patches of a
standard IT8 target and the specific colors an image contains are measured. (See my website for
step-by-step text and videos on how to do this.) In many cases, one image specific profile can be
used to improve printed results for many other images containing similar colors.
How can you tell if a printer profile is good? Two ways. One, print test charts with both synthetic and
real world information. (Download them from my website.) If your printer renders poor shadow
and/or highlight separation, neutrality and/or graybalance, or gradation, use another profile. Two,
graph them. (Use Apple’s ColorSync Utility or Chromix’s Color Think software.) If the 3-D volumes
they render are highly irregular, truncated, or contain spikes and/or holes in them, use another
profile.
Good and bad profiles compared. Irregular shapes, truncations, and holes are signs of bad profiles.
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Test prints allow real world evaluations of results from profiles.
Printer profiles can make or break print quality. With today’s advances in printer profiling
technology, they rarely do. But, printer profiles always make both significant and subtle differences
in quality that are substantial enough to warrant serious care and consideration. Rely on trusted
sources to provide you high quality printer profiles and/or learn to make them yourself. Then, test
the profiles you use to confirm that you’re truly getting the highest quality profiles possible. You
need them to make the highest quality prints possible. Both you and your images deserve the best.
Editing Spaces Compared
Four standard device neutral RGB editing spaces compared
sRGB – red; Colormatch – green; Adobe RGB – blue; ProPhoto – full color
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From small to large, standard RGB editing spaces include sRGB, Colormatch, Adobe RGB (1998), and
ProPhoto. Only ProPhoto RGB can contain as much or more color as your camera can capture. This is
why I recommend ProPhoto RGB as my first choice of these editing spaces. ProPhoto RGB has the
widest gamut.
The term gamut is used to describe the total capacity of a color space. Wider gamut color spaces are
capable of containing more saturated color than smaller gamut color spaces. ICC profiles are used to
describe color spaces. ICC profiles can be graphed as XY chromaticity diagrams, which can be used to
compare the gamuts of color spaces. On the center axis are neutral colors. As you move away from
the center color becomes more saturated. A larger area indicates a greater ability to hold more
saturated data. The contour defining that area marks the gamut boundary, the limit of saturation
that color space is capable of holding.
Capture your images in wide gamut color (Raw) and edit them in wide gamut color (ProPhoto RGB).
Convert only copies of your master files into smaller gamut spaces for output specific uses.
Converting images from wider gamut spaces to smaller gamut spaces reduces saturation. Converting
images in smaller gamut spaces to wider gamut spaces doesn’t increase saturation.
Why? Think of a bucket full of water. If the water is color, then the bucket that holds it is the editing
space. If you pour water from a big bucket into a small bucket, some of the water will be lost.
Pouring the smaller volume of water back into the larger bucket won’t make the total volume of
water larger; it will be the same amount of water sitting in a larger bucket. Start wide and stay wide.
Choose A Wide Gamut Editing Space
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Today’s inksets can exceed the gamut of even the best monitors in yellows, oranges, and blues. Epson
UltraChrome HDR ink on Epson Exhibition Fiber is plotted against sRGB, Adobe RGB (1998) and
ProPhoto.
The gamut of this image and the print made from it exceeds the gamut of Adobe RGB (1998) and the
monitor. You have to make a print to see the most saturated color possible.
Choose a wide gamut editing space to make the best prints possible. If a file’s color space is smaller
than the printer’s color space, you won’t be able to realize the full saturation your printer is capable
of.
Today’s inksets exceed the gamut of all but one of the standard editing spaces (sRGB, Colormatch,
and Adobe RGB (1998)), making ProPhoto the best choice for creating files in. Since ProPhoto
exceeds the gamut of human vision, it’s unlikely that you’ll ever need a wider gamut editing space
than ProPhoto. If you create your files in ProPhoto you’ll be well positioned to take advantage of
future advances in printer and media technology. So, choose ProPhoto.
How do you do this?
1 If you’re converting a Raw file, choose ProPhoto in the Raw converter’s interface.
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2 If you’re exporting a file from Lightroom, choose ProPhoto.
3 If you’re creating a new file in Photoshop, set ProPhoto as your default color space.
4 If you’re scanning an image, choose ProPhoto in the scanner’s interface.
ProPhoto is so wide that when you use it, you need to edit 16 bit mode. Basically, the steps between
individual values is much larger than smaller gamut editing spaces, so without enough shades of
gray, significant edits may produce posterization or banding. In contrast to the 256 shades of gray in
8 bit files, 16 bit files provide 65,536 shades of gray – more than enough to eliminate this problem.
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When you use ProPhoto, be careful when increasing saturation. ProPhoto exceeds the gamut of
even the most sophisticated monitors, so it’s possible to oversaturate values in files without seeing
it. In a majority of cases you won’t be able to display or print these values, but in some cases you
may be able to, and in the future you most certainly will. So, in general, when you use Saturation or
Vibrance sliders stop at the point where you don’t see changes. More often than not, saturation that
exceeds the gamut of monitors is best optically captured by devices like cameras and scanners,
rather than synthetically produced.
You may not want to use ProPhoto files for specific applications. While today’s inkjet printers can
put ProPhoto’s saturated colors to good use, not all devices can or do. For instance, many offset
presses prefer CMYK files and some web browsers disregard ICC profiles making ProPhoto files look
oversaturated. In cases like this, convert copies of your ProPhoto files to smaller color spaces for
specific uses.
If you’ve already created files in color spaces other than ProPhoto, don’t convert them into
ProPhoto. You won’t get more saturated colors. All you’ll get is the possibility of having more
saturated colors. It’s better to know that the gamut of a file has been compressed to a smaller color
space. If you convert files like these to ProPhoto, you may be able to add synthetically created colors
or increase the saturation of colors with software, but these colors never have the complexity of
optically captured colors. To take full advantage of ProPhoto in these instances, recreate a file by
reconverting or rescanning them. Do this only with files that will benefit by using ProPhoto. Only
images with highly saturated colors will benefit; images with low saturation will not.
ProPhoto is your best choice of editing spaces for making the best prints possible now and in the
future. Position yourself well to take advantage of the latest advances in printer technology by
taking a few simple steps when you first create your image files. It’s as simple as setting it up once
and using it consistently ever after.
Benefits of Editing Images In 16 Bit Mode
What’s the difference between 8-bit and 16 bit? The number of shades of gray. 256 versus 65,536 to
be exact. With more shades of gray, gradation becomes smoother.
How do you get at these numbers? Digital files are binary. 2 to the 8th power is 256. 2 to the 16th
power is 65,536.
2 1 = 2
2 2 = 4
2 3 = 8
2 4 = 16
2 5 = 32
2 6 = 64
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2 7 = 128
2 8 = 256
2 9 = 512
2 10 = 1024
2 11 = 2048
2 12 = 4096
2 13 = 8192
2 14 = 16,384
2 15 = 32,768
2 16 = 65,536
16-bit files take twice as much memory to store all those shades of gray. It’s worth it. For an
arithmetic increase in file size you get a logarithmic increase in the number of shades of gray.
256 shades of gray are just enough shades of gray to do reasonably well for most imaging
applications. The human eye can see approximately 1,000 shades of gray. With 65,536 shades of
gray, 16-bit files contain tens of thousands of shades of gray more than you can see.
So what are all those extra shades of gray good for? Editing your files to get the best results possible.
When a digital file is edited, it loses some shades of gray. If a digital file contains too few shades of
gray, it begins to posterize. You may see signs of posterization if an image’s histogram displays
combing or gaps and spikes. Before you panic, examine smooth areas of an image to make sure
there’s visible posterization. Do this at 100% screen magnification; many times the posterization you
see on a monitor is a result of a monitor not being able to display the data as smooth as it is at other
screen magnifications. 16-bit files contain so many shades of gray, it’s very difficult for posterization
to occur with normal editing – unless you deliberately posterize it with digital filtration.
16-bit doesn’t extend color gamut; 16-bit files can be either small or wide gamut. 16-bit is
recommended for files created in wide-gamut color spaces, like Pro Photo RGB, because the steps
between tonal values are spread out over a larger distance to achieve greater saturation and so tend
to posterize more quickly.
16-bit doesn’t extend dynamic range; it doesn’t generate a blacker black or a whiter white. 16-bit
source files are recommended for high dynamic range because HDR images are heavily processed
when tone-mapped and would posterize without higher bit depths. In HDR processing, multiple
bracketed 16-bit files are combined into a single file with a 32-bit mode used to hold the varied data
they contain over a dynamic range that is wider than the device that created them. A 32-bit file is
subsequently tone-mapped and rendered down to a 16-bit file with an improved dynamic range.
With the exception of 32-bit files used for HDR tone-mapping, files in Adobe Photoshop can either
be either 8-bit or 16-bit.
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To get true 16-bit data, you need to generate it when you create a digital file – and preserve it during
image editing. JPEG files can’t contain 16-bit data; they’re cooked down to 8-bit. Raw files can. (So
can scanned images.)
Not all Raw files contain a true 16-bits of data. While many DSLRs can only generate 10-bits, 12-bits,
or 14-bits data, all DSLR Raw files contain more than 8-bits of data, which can only be preserved in
Photoshop if edited in 16-bit mode.
You can change a digital file’s mode from 8-bit to 16-bit, but doing this won’t magically add shades
of gray to the old 8-bit data; all this does is create the possibility of adding new 16-bit data
information on top of the old 8-bit data; and it doubles a file’s size.
Editing files in 16-bit mode limits some of Photoshop’s functionality; many filters don’t work in 16-bit
mode.
You can apply a filter to an 8-bit copy of a 16-bit file and drop and drag the filtered file into the
original 16-bit file as a layer. Again, the layer won’t have 16-bits of data and may be adversely
affected by subsequent edits if they are aggressive. If edited minimally, the results can be quite
acceptable.
Editing your images in 16-bit mode is worth the time and effort. You’ll generate fewer imaging
artifacts during editing and so create better finished files.
Right now, creating 16-bit files is largely about generating the best 8-bit data. (Most monitors can
only display 8-bits of data. Improved results in print can only be discerned by the very discriminating
eye in select files.) In the future, when monitors and printers make better use of more than 8-bit
data, you’ll begin to see visible improvements in gradation when your images are viewed in both
display and print.
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A smooth histogram.
A posterized histogram.
Gaps happen when contrast is increased; tones that were close together are spread apart. Spikes
happen when contrast is reduced; tones that were close together become the same.
Avoid this by editing in 16-bit.
What To Do With Photoshop’s Color Management Dialogs
Knowing what to do with the color management dialog boxes you encounter while you’re editing
your digital images in Photoshop is the key to making sure that the rich, saturated, wide-gamut color
you choose to master your files in stays wide-gamut and doesn’t change – unless you want it to.
When you set Color Settings in Photoshop (Edit : Color Settings), you not only choose Working
Spaces (RGB, CMYK, Gray, and Spot) to create new files in (Choose ProPhoto RGB for the widest-
gamut color space.), you also set Color Management Policies that determine what happens when
you’re dealing with files that are not created or edited in the same color spaces.
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For RGB, CMYK and Grayscale files you can choose to turn Color Management Off, to Preserve the
Embedded Profiles, or to Convert to Working color spaces. You rarely, if ever, want to turn color
management off; you only do this when you want to ensure that no color space conversions take
place, for example when opening target files for creating printer profiles. Similarly, you typically
don’t want files automatically converted to a default working color space without your knowing that
it’s happening, as they are when you set the policy to Convert to Working; you’d only want this to
happen when you’re batch converting a number of files to quickly bypass color management dialog
boxes. In the vast majority of cases, you’re better off served leaving the default settings at Preserve
Embedded Profiles. This way, any time a color management operation is about to take place, you’ll
get one of three dialog boxes that not only alert you but also give you control over how the
operation is handled.
So what do you do when you encounter these three dialog boxes – Missing Profile, Profile Mismatch,
and Paste Profile Mismatch?
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The Paste Profile Mismatch dialog box makes it all very clear. You encounter it when you’re pasting
information from a file in one color space into a file in another color space. (Photoshop can open
many files in many color spaces at one time, but a single file can have only one color space at one
time.) The parenthetical remarks in the Paste Profile Mismatch dialog box say it all. If you Convert
you “preserve color appearance”; Photoshop does this by referencing the ICC profiles of the source
and destination color spaces and precisely changing the numbers in the file so that they produce the
closest possible match to the original appearance; only the appearance of very saturated colors will
change if you convert a file to a smaller gamut color space. If, on the other hand, you Don’t Convert
but “preserve color numbers”, the appearance of a file will change, sometimes dramatically, because
a new color profile has been assigned but the numbers in the file have not been converted at the
same time.
Wait! Am I saying you have to change to stay the same? Yes. You have to change the numbers, or
convert them, to preserve their color appearance. Why? Because the same numbers in two different
color spaces, like ProPhoto RGB and sRGB, mean different things. The same values in a file (0 to 255)
are spread out over a much greater distance (a wider gamut) in ProPhoto RGB, producing more
saturation. So, the appearance of the same numbers (100,100,50) vary significantly in saturation in
ProPhoto RGB and in sRGB because their gamuts are so different. Only the appearances of equal or
neutral values (i.e. 10,10,10 or 128,128,128) remains the same in all RGB device neutral color spaces
(sRGB, Colormatch, Adobe RGB (1998), ProPhoto RGB).
With this in mind, you rarely want files without profiles. Files without profiles vary wildly in
appearance based on the device displaying them. Untagged files indiscriminately toss their
unchanged numbers into different color spaces, editing/working color spaces or a device’s color
spaces and so their appearance constantly changes. Untagged files are unpredictable and unstable.
The only time you want files like this is when you’re profiling a device, like a printer. Then, not
knowing what the color space of the device is, you send known numbers to it and measure what
appearance they generate. With this information you can create an ICC profile that describes the
devices behavior.
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So, if you encounter a file that’s missing a profile assign one. Just don’t do it with the Missing Profile
dialog box; with it you can’t preview the results while you’re choosing a profile. Instead, when you
encounter the Missing Profile dialog box, check Leave as is (don’t color manage) and OK, opening the
Untagged file. With the file open, go to Edit : Assign Profile, check Profile and select a profile that
generates a pleasing appearance. If you’re lucky enough to know the profile that’s been removed
from a file (the right answer) assign that profile but in most cases you won’t know, so just choose a
profile that makes the file look as close to what you want as possible (the best answer). Then save
the file with the profile attached to it. (Once it’s converted, leave it in that color space; don’t convert
it to a wider gamut space thinking you’ll get more saturation – you won’t.) You may note that though
the appearance of an image changes dramatically when a profile is assigned, the numbers it contains
don’t change. (There is a very advanced method of adjusting color by assigning a synthetically
created profile to an image to generate a pleasing appearance without changing the numbers, hence
you can make dramatic changes to an image virtually non-destructively. But it’s prohibitively
complex and unintuitive to make it useful in most situations.)
With a clear understanding of the difference between assigning a profile and converting to a profile,
the Embedded Profile Mismatch dialog box, the one you’ll encounter most often, becomes
straightforward. In a majority of cases, simply check “Use the embedded profile (instead of the
working color space)”. Don’t check “Discard the embedded profile (don’t color manage)”, unless you
know the file has been assigned an incorrect profile. “Convert the document’s colors to the working
space” only during batch conversions, for instance when you’re converting a number of copies of
files to sRGB for the web. (Do this with copies only. If you convert your originals from wider gamut
color spaces, you’ll lose the greater saturation they contain permanently.) Minimize the number of
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color space conversions a file goes through. They’re cumulatively destructive. Making only two color
space conversions is ideal: first from source to a device neutral editing color space; second to a
device specific output/display color space.
If you haven’t been using wide-gamut editing spaces like ProPhoto RGB don’t think that you can
improve your legacy files by simply converting them to a larger gamut editing space. All this does is
give you the potential for more saturation. To actually get more saturation you also have to enhance
your files with software after conversion; even then the saturation you get will tend to lack variety in
luminosity and hue. The best way to get the extra saturation with rich variation in luminosity and
hue is to return to the source, your original file (Raw file or scan), and convert it into a wider gamut
editing space.
Information converted from sRGB into ProPhoto RGB does not get more saturated. The editing space
becomes wider gamut but the potential for increased saturation can’t be accessed unless values in
the file are enhanced with software. The best way to get saturated color is to convert it from it’s
source into a wide-gamut editing space like ProPhoto RGB.
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Understanding the difference between assigning and converting to a profile is one of the most
conceptually challenging things about color management in digital imaging. It’s counterintuitive to
think that by changing numbers the appearance of colors will stay the same or that if you don’t they
won’t. But, once you understand why this is happening, how to set up your color management
environment in Photoshop, and what to do when you encounter these color management dialog
boxes things will become much simpler. If you adopt a consistent workflow and always convert into
and create new files in the same color space you often won’t encounter these dialog boxes. You’ll
quickly find you won’t have to think about it any more. You’ll simply take appropriate action with
confidence when you need to. And you’ll rest assured that the images you’re creating are the very
best that can be created.
Rendering Intents Compared
Original posted by John Paul Caponigro at
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gamut clipping
gamut compression
Your choice of a rendering intent tells a color management system how to handle color conversions
between different color spaces. This is particularly important when converting colors from a wider-
gamut color space (such as an editing space like ProPhoto) to a smaller-gamut color space (like a
Original posted by John Paul Caponigro at
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printer color space). You’ll get different results, even when using the same ICC profile, depending on
the rendering intent you choose for a color conversion. You have four choices; perceptual, relative
colorimetric, absolute colorimetric, and saturation.
What’s the difference between these four rendering intents?
Here’s the get it done explanation.
Perceptual
Use a perceptual rendering intent for printing images with highly saturated colors. Watch it carefully.
To deliver very saturated colors, it may lighten an image or shift the hue of specific colors. Both side-
effects can be compensated for with output specific adjustments.
Relative Colorimetric
Use a relative colorimetric rendering intent for printing images where the luminosity structure is
most important. You may get slightly less saturated colors but brightness values will be most stable
with this rendering intent. This makes it the ideal choice for near neutral and black and white
images.
Absolute Colorimetric
Use an absolute colorimetric rendering intent for making a proof of one device on another, like
making a proof of an offset press on an inkjet printer. It’s not useful for making the best inkjet print;
it will limit the results the printer delivers. Note, you can’t simulate a printer with a greater gamut
than the device you’re printing on, only one with a smaller gamut.
Saturation
Use a saturation rendering intent for eye-catching graphics where color impact is more important
than color accuracy , like pie charts. It will so much saturation it will distort continuous tone images
in an adverse way.
Here’s the color geek explanation.
Perceptual
A perceptual rendering intent preserves the overall color appearance by changing all colors in the
source space to fit the destination space. The perceptual rendering intent is favored for images that
contain many out-of-gamut colors.
Relative Colorimetric
A relative calorimetric rendering intent maps the white of the source space to the white of the
output. It reproduces in-gamut colors exactly and clips out-of-gamut colors to the nearest
reproducible color. The relative calorimetric rendering intent is a good choice for images where
more of the colors are in-gamut than out-of-gamut.
Absolute Colorimetric
An absolute colorimetric rendering intent differs from relative colorimetric because it doesn’t map
the source white to the destination white. It reproduces hues absolutely. If the source is a clean
white reproduced on yellow paper the result will be a yellow white. If the source is a cool white
reproduced on a warmer paper, cyan ink will be used to simulate the cool white of the source. Th
Original posted by John Paul Caponigro at
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absolute colorimetric rendering intent is intended for cross-rendering simulations of output
condition with another.
Saturation
A Saturation rendering intent converts saturated colors in the source space to saturated colors in the
destination space. It favors reproducing vibrant colors and will do so at the expense of reproducing
hue or luminosity accurately. The saturation rendering intent is useful for reproducing graphics with
high color impact.
Here’s the bottom line. To make the highest quality prints possible, choose either relative
colorimetric or perceptual. As results vary from image to image, softproof an image to choose which
rendering intent is best for it, before you print it.
Profile Your Printer
Prints made with default (left) and custom (right) profiles compared.
Good printer profiles help make good prints. Better printer profiles help make better prints. So,
logically, you’ll want to use the best printer profiles to help you make the best prints.
How do high quality printer profiles contribute to print quality? A good printer profile helps render
optimum shadow and highlight detail, gradation, neutrality and graybalance, as well as color
rendition and saturation. (Remember, printer profiles characterize the combination of a printer’s
hardware, ink, media setting, and the substrate you choose. You’ll need different profiles for
different substrates on the same printer.)
How can you get good printer profiles? Look to three primary sources. One, use profiles provided by
printer manufacturers; they’re free. Two, hire a printer profiling service; profiles cost approximately
$100 each. Three, make printer profiles yourself; printer profiling systems run between $400 and
$1000. (Profiles supplied by substrate manufacturers are of uneven quality; a few are good, many
are bad.)
Which solution is right for you? It depends on both your printing conditions and needs.
If you’re using substrates supported by the manufacturer of your printer, try using the profiles they
provide first; they’re often quite good. Years ago, Epson raised the bar on the quality of printer
Original posted by John Paul Caponigro at
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profiles provided by manufacturers. The highly sophisticated routines they use to produce their
printer profiles processed by supercomputers are truly state-of-the-art. It’s arguable that you can
produce better profiles, even with the most sophisticated profiling solutions available. Their profiling
routines factor in subtleties like dot structure or screening frequency. One of the reasons a solution
like this works is because the technologies and manufacturing standards they use are so consistent
that the unit to unit variation between individual printers of the same model is extremely low. (It’s
less than a Delta E of 1 or the minimum variation the human eye can detect.) Some, printer
manufacturers, like Canon, provide a large number of profiles for substrates made by other
companies; their quality is generally quite high with only a few exceptions. Other printer
manufacturers, like HP, produce self-profiling printers. They need to be self-profiling, as the state of
the printer is constantly changing; when nozzles clog, new nozzles come on line; when ink cartridges
are swapped nozzles are replaced. One advantage to a system like this is you can quickly profile a
new substrate on a printer with no additional equipment. The quality of the profiles is often good,
but there will be times where you’ll want to improve upon it.
No manufacturer provides a comprehensive set of profiles that will cover the entire spectrum of
fast-evolving substrate industry. A little experimentation with new media is advised, sometimes a
lot. If you experiment with many medias or use more exotic substrates, you’d be well advised to
have someone make custom profiles for you or do it yourself.
Test Files
This is video, to watch it go to this address.
Managing Camera Profiles
If you make camera profiles customized for your camera, sooner or later you’re going to want to
rename or delete a few. Where do you find camera profiles? On the Mac, follow this trial User :
Application Support : Adobe : Camera Raw : Camera Profiles.
X-Rite offers a free easy to use software for managing camera profiles – DNG Profile Manager. With
it, you can activate, deactivate, delete, move, export or rename camera profiles.
Download X-Rite’s DNG Profile Manager here.
Read more in my color management ebooks.
View more in my color management DVD.
Learn more in my digital photography and digital printing workshops.
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Using X-Rite’s Color Checker Passport – Target Or Profiles
X-Rites’ Color Checker Passport can be used to quickly deliver more accurate color in a variety of
ways.
Set White Balance, White Point, and Black Point
The X-Rite Color Checker Passport is the industry standard target that can be used in several ways to
render color in your digital images more accurately – setting white balance, creative enhancement,
and visual confirmation.
It’s easy to use. Shoot the Color Checker once at the beginning of each shooting session and you can
use that exposure as a target for all exposures made under the same light. The exposure of the
target doesn’t have to be perfect. Just, roughly fill the frame with the target; it doesn’t even have to
be focussed. To use the exposure of the target, use your choice of Raw conversion software to open
it along with other exposures you’d like to apply the same measurements to; click on the
appropriate color patches (black for black point, white for white point, gray for gray point); and sync
all of the files. It’s that simple.
Original posted by John Paul Caponigro at
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Create A Camera Profile
The X-Rite Color Checker Passport can also be used to make custom profiles for your individual
camera. You can create a camera profile with the same exposure of the target that you use to set
white balance. While camera profiles are generated with the same target, the resulting exposures
are not used to set white balance, instead they are used to deliver significantly improved color
rendition and saturation, providing the best starting point for any color adjustment strategy you
choose. Camera profiles are created with the X-Rite software supplied with the Color Checker
Passport, stored, and later applied with your choice of Raw conversion software, typically Adobe
Camera Raw or Adobe Lightroom.
For optimum results, exposures used to generate camera profiles need to be made under the light
(color temperature and spectral distribution) that subsequent exposures are made in. Using two
exposures of the target made under different light temperatures, you can create a dual illuminant
camera profile that can be used for all exposures made under a wide range of color temperatures.
Single illuminant profiles are recommended for exposures made under very warm or very cool light
temperatures – below 3600K (golden hours) and above 6800K (twilight).
How do you make a camera profile? First convert one or more exposures of the Color Checker
Passport from the manufacturer’s proprietary Raw format to Adobe’s open standard Raw format –
DNG. (Use either the free Adobe DNG Converter, Adobe Bridge, or Adobe Lightroom.) Open X-Rite’s
Color Checker Passport software. Click DNG or Dual Illuminant DNG. Drag one or two DNG files into
the open window. Once the software has identified the specific color patches it needs to build the
profile, click Create Profile. The profile will automatically be stored for you in Camera Profiles and
will be available for your use the next time you convert a Raw file in either Adobe Camera Raw or
Adobe Lightroom. You’ll find it under the Camera Calibration tab/panel under Camera Profile. Save
New Camera Raw Defaults and your new camera profile will be automatically loaded when you open
Raw files and previews in Adobe Bridge will be rendered with it.
Using a Color Checker Passport target or a camera profile generated with it doesn’t mean that you
are locked into the results they generate, they simply give you the best starting point possible for
adjusting your images.
Original posted by John Paul Caponigro at
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Original posted by John Paul Caponigro at
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before (left) / after (right) comparison
Original posted by John Paul Caponigro at
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Softproofing
As a rule, always softproof an image to determine a rendering intent and make printer/substrate
specific adjustments to a image file before printing it.
You can get Photoshop to display an image the way it will appear when it’s printed, before you print
it, by softproofing an image. If you softproof before you print, you’ll get your best first proof or
maybe even a finished print. Not to be confused with a hard proof or physically printed piece, a
softproof uses an ICC profile to create an onscreen simulation of an image as it will appear when
printed.
Wait. Haven’t you already done this by calibrating and characterizing your monitor with a
colorimeter, choosing an editing space along with color management policies in Photoshop, and
specifying the right profile for a printer/paper combination with your printer driver? Almost. Doing
these things ensures that all of the different color behaviors of the devices you’re using are
accurately described and that color conversions are handled precisely, but it doesn’t ensure that you
will see exactly how an image will look when printed. Without softproofing, you see how an image
looks on a monitor. To see an image on a monitor with the appearance of how it will look when
printed, before you print it, you need to take the final step of softproofing the image. This simulation
won’t change your file, just it’s appearance. Once softproofed, if you choose to, you can make
output specific adjustments to your file before printing to get a better first print.
How To Softproof
To softproof an image go to View: Proof Set Up: Custom and choose the ICC profile that describes a
particular substrate on a particular printer. Photoshop uses the selected ICC profile to simulate the
appearance of the final print.
Original posted by John Paul Caponigro at
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It is essential that you specify the correct ICC profile and that the profile be accurate. The default
profile for Proof Set Up characterizes a standard web offset press. If you’re printing to another
device, to get an accurate preview, you need to specify a profile that accurately describes its
behavior. The softproof is only as good as the profile used. A bad printer profile will give you a bad
softproof and a bad print. If you find a profile doesn’t make a good softproof or print, use a better
printer profile.
Choose A Rendering Intent
Always softproof an image before printing so that you can choose a rendering intent. Your choice of
rendering intent will have a significant impact on print quality. Rendering intents are methods of
gamut compression, or how out-of-gamut values are treated relative to in-gamut values. Your choice
of four rendering intents can be simplified to two. Forget about Saturation, which is useful for bold
graphics but causes color distortions in continuous tone images. Forget about Absolute Colorimetric,
which is useful for cross-rendering or simulating the behavior of another device, like making a proof
of an offset press – it won’t deliver the best quality a printer is capable of. Use Perceptual to
maintain saturation, very often the side effect is that the image is lightened somewhat. Use Relative
Colorimetric to maintain tonal relationships, very often some saturation is sacrificed. This is one case
where exceptions prove the rule. Always compare these two rendering intents when you softproof.
Pick the rendering intent that gives you the view you like the most.
Simulate Ink Black and Paper White
Checking the Simulate Paper White and Ink Black options is advisable. Because a monitor is capable
of displaying a brighter white and a darker black than a print, one dulls the whites (Simulate Paper
White) and the other dulls the blacks (Ink Black). Activating these features will not make the image
look better but it will make the preview more accurately match the print. In my opinion, the preview
generated using these features is aggressive, it moves the image in the right direction but it often
takes it a little too far. So, I use these options to frame reasonable expectations but I don’t rely on
them when making corrections to a file.
Check Black Point Compensation
Use Black Point Compensation. If you don’t, detail in shadows may be clipped and lose separation.
Viewing Light Temperature
Original posted by John Paul Caponigro at
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The light you view your prints under is important. Printer profiles are generated for specific light
temperatures. Typically profiles are generated for viewing under a light temperature of 5000K. The
softproof will not be as accurate as it can be if you view the print under another light temperature. If
you want to make prints for other light temperatures, such as warmer lights like halogen or
tungsten, use a profile optimized for those light temperatures. Alternately, use a 5000K profile, but
expect the print to appear warmer than anticipated when viewed under a warmer light. You can
make appropriate compensations to your image by color adjusting your file to a slightly cooler color
(cyan/blue).
Compare Two Views At Once
It’s helpful to see a file both before and after it has been softproofed simultaneously. To do this, look
at two versions of the same file simultaneously. First, softproof the file. Second, duplicate the file
(Image: Duplicate); the duplicate will not be softproofed. Comparing the two versions will help you
see how your image will change when printed and how to compensate for these changes with
additional output specific adjustments.
Make Output Specific Adjustments
Softproofing does not change the file, it simply previews how the appearance of an image will
change when printed. Once you see how an image will change when printed, you may decide to
adjust the file to compensate for those changes, before printing. You can make a printer/paper
specific set of corrections, while a file is being softproofed. Start by making a new Group with the
printer/paper combination included in the title. Then create a set of adjustment layers to make the
softproofed image match the unsoftproofed image as closely as possible. Typically, midtone contrast
is added with Curves (to compensate for dynamic range compression) and Hue/Saturation is used to
boost the saturation of in-gamut colors (to compensate for gamut compression). Use these
corrections for printing to that specific output condition (printer/ink/paper/profile) only. Turn the
layer set off for all other uses of the image.
Original posted by John Paul Caponigro at
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Pick Your Battles
Pick your battles. Out-of-gamut means unprintable.
Don’t try to get a blacker black or a whiter white by further adjusting your file’s black points and
white points. If an image’s black points and white points were already set precisely, all you’ll succeed
in doing is clipping detail. Instead, accept the limitations of ink on paper and compensate with
midtone contrast. Alternately, use a paper that can generate a blacker black, for instance switch
from a matte to a glossy surface.
If an image contains out-of-gamut color that is too saturated for a device to print don’t try to
increase the saturation of the image to make them more saturated. You’ll run the risk of
oversaturating in-gamut or printable colors. Instead, accept those limitations and target increases in
saturation to in-gamut colors only; they too may be affected by gamut compression and you can
take steps to prevent this. You can see which colors are out-of-gamut by dramatically increasing
saturation while an image is being softproofed; the colors that change are in-gamut while the colors
that don’t change are out-of-gamut.
Ignore Photoshop’s Gamut Warning. It often doesn’t indicate what’s out of gamut accurately, often
it’s far too conservative, and it can’t show you where the in-gamut colors that are affected are.
Original posted by John Paul Caponigro at
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Mindful of these limitations, use any means at your disposal to make the softproofed image match
the unsoftproofed image as closely as possible.
It’s inevitable that an image will undergo changes when printed; sometimes a little and sometimes a
lot. Always softproof an image before you print so that you can frame reasonable expectations,
determine a rendering intent, identify how an image will be affected by gamut-compression, and
make corresponding output specific adjustments.
How accurate can a softproof be? Extremely accurate. Glass transmitting light will always look
different than paper absorbing light. However, you can get one to closely simulate the appearance
of the other. Softproofing will save you time, materials, and money. Softproofing will help you get
better prints.
Review – ColorThink
Save $30 on ColorThink.
Save $60 on Color Think Pro.
Save $30 on Color Valet.
Save $60 on Color Valet Pro.
They say “A picture is worth a thousand words.” In some cases, it’s worth far more. That’s certainly
true of the images generated by CHROMiX’s ColorThink. The folks at CHROMiX say, “You can’t
manage your color if you don’t understand it. Nothing gets the idea across faster than the graph of a
printer gamut.” They’re right.
CHROMiX ColorThink is the award-winning color management toolset that helps you understand
your color more than ever before, primarily (but not exclusively) by graphing it. The ColorThink
Original posted by John Paul Caponigro at
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toolset is an application for managing, repairing, evaluating and graphing ICC profiles, composed of
nine modules that are proven to “keep your brain on color”.
Profile Manager
Organize your profiles individually or in sets
Profile Inspector
Open all types of ICC Profiles and inspect their color data and other details. Change default settings
to fit your workflow. Display neutral rendering curves.
2D Graphing
2D graphing gives you both general and specific views, allowing the overlay of multiple profiles and
data sets.
3D Graphing
3D graphing gives you the whole picture. Analyze your devices and workflow. See the cause of
proofing and printing problems. Graph measurement files and image colors to compare with device
gamuts.
Image Inspector
Open images and see the embedded profile. Export, change(mac only) or delete(mac only) it at will.
Learn to handle the files your customers are sending.
Profile Renamer
Profiles have two names; internal and external. Confused by what appears in menus? Change the
internal and external names with this tool.
Profile Linker
Some RIPs allow linked profiles to be loaded for proofing purposes. Profile Linker will build those
profiles for you, quickly and easily.
Profile Medic
Multi-point integrity checks can be performed on one or all the profiles in your system. If Profile
Medic finds fixable problems with a single click it will get you back to work.
Color Lists
Open measurement files from most profiling applications. View them in list form with rendered
colors. Apply profiles to the lists for testing and graphing.
ColorThink 2.x lists for $149. ColorThink Pro lists for $399. Upgrades from ColorThink 2.x to
ColorThink Pro are $249. Among the many features added in ColorThink Pro are enhanced graphing
and profile analysis capabilities; graphs have more detail and automation; background color can be
altered; graphs can be saved as movies; profiles can be displayed as points; CMYK and Lab images
can be graphed; and you can slice image data and vectors at any lightness value. Can’t decide which
to start with? Start with ColorThink 2.x and upgrade ColorThink Pro later, once you see how
indispensible this utility really is.
ColorThink is a very robust color management software. Only a few advanced users will use its full
toolset. But almost everyone can benefit from using a few of its most essential features.
Original posted by John Paul Caponigro at
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For me, graphing color is the core utility of this tool. Graphs are useful abstractions. When you’re
dealing with a lot of information, graphs can condense and focus information from specific
perspectives revealing useful information. This is certainly true of color. Because color has three
dimensions (luminosity, hue, and saturation), graphs of color in 2D always leave something out,
while graphs of color in 3D give you a more complete picture and more useful perspectives.
ColorThink gives you powerful tools for graphing color in both 2D and 3D. You can graph ICC profiles
(input, display, output), color, color lists, or images. You can graph multiple profiles simultaneously
for comparison. You can graph profiles and images simultaneously for comparison. You can view
graphs in multiple formats such as shaded objects, wireframes, points, and vectors. You can change
color and transparency to make comparison easier. And you can rotate, pan, and zoom your
viewpoint dynamically.
Every time I lecture on color, I use ColorThink. Every time I evaluate a new inkset or substrate or
printing profile, I use ColorThink. While I don’t graph every image before I print it, I do graph
particularly challenging images to print and ColorThink always reveals useful information. I
recommend it highly.
This utility not only expanded my understanding of color and color management but it has also
helped me refine an advanced perspective on color theory (the conceptual tools artist’s often use to
help structure color palettes and make color choices). It’s my hope that in the 21st century 2D color
wheels (such as Leonardo’s, Goethe’s, and Itten’s) will be replaced with 3D color volumes.
1 An image.
Original posted by John Paul Caponigro at
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2 A 2D graph (two profiles and an image) tells only part of the story. The gamut of semi-gloss
papers seem moderately extended when compared to matte papers; the image appears in gamut for
both.
3 A 3D graph of two profiles tells you more. Semi-gloss papers have greatly extended dmax and
gamut in dark values but reduced gamut in lighter hues; warm highlights are out of gamut for both
(better highlight saturation is found in matte) and cool shadows are out of gamut for matte.
Original posted by John Paul Caponigro at
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4 Gamut can be sliced at specific luminosity values.
5 Display the effects of profiles on colors in images with vectors.
Visit the ColorThink product pages at www.chromix.com to learn more.
Review – SoLux Lighting
Original posted by John Paul Caponigro at
http://www.johnpaulcaponigro.com/downloads/technique/color-management.php
Good light makes your prints appear even more beautiful. Get good light. It’s one of the most
essential elements in any photographic image, at the point of capture, during processing, and at the
point of display.
SoLux (www.solux.net) makes good light. SoLux bulbs’ Color Rendering Indexes (rating used to
describe the quality of light) are 99 on a scale of 100. All SoLux bulbs are full smooth spectrum and
ultra low UV and IR. SoLux bulbs come in a variety of color temperatures – 3500K, 4100K, 4700K, and
5000K. SoLux bulbs come in a variety of beam angles – 10-36 degrees. Low voltage (12 volt), SoLux
bulbs fit in standard MR-16 2 pin socket fixtures and adaptors are available for regular screw in
fixtures.
While light has many important qualities, two are particularly significant; temperature and spectral
power distribution.
Most prints are viewed under light temperatures warmer than 5000K, typically a mix of tungsten
(2800K) and daylight (variable). Galleries and museums favor halogen (2900K). Studies suggest that
more people prefer viewing artwork under higher color temperatures (3500K).
A majority of artificial light sources, including fluorescent, metal halide, and LEDs, have an uneven
distribution of colors. Graphs of light sources with uneven spectral distributions display spikes in
specific regions of the spectrum. Spikes limit the number of available colors in a spectrum to discern
an object’s color. Due to missing colors in between spikes, objects may look dull or gray. When a
spectrum is uneven, hues that are found in elevated levels appear brighter while hues that are found
in low levels appear duller. Spikes create an imbalance in the relationships between hues. When
possible, avoid lights that have them.
Incandescent light contains large amounts of yellow, orange, and red light. Though not as extreme,
halogen suffers from the same tendencies. Cool white fluorescent light may produce a white that is
cooler in appearance, but all fluorescent lights have uneven spectral distributions.
How important is viewing light? Very. To many, at first glance, the differences may seem subtle. To
truly appreciate the differences you need a side-by-side comparison of the same or identical objects
in spikey and smooth spectrum light sources.
The curators of the Van Gogh Museum (Netherlands) visited their traveling collection while it was on
display at the National Gallery of Art (US). “What have you done with our paintings?” they
Original posted by John Paul Caponigro at
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exclaimed. They thought they had been cleaned. “Nothing.” was the reply. The real answer was in
the light – SoLux. Under full spectrum light sources the paintings appeared significantly brighter,
clearer, and more saturated. The Van Gogh Museum now uses SoLux bulbs. More and more
museums are beginning to use SoLux bulbs as well.
I use SoLux 3500K bulbs for my studio and gallery. I evaluate and display prints under the same light,
one that most closely approximates the display conditions prints are most likely to be viewed under.
I use four SoLux Gooseneck fixtures for portable light sources; two with 3500K bulbs to evaluate
display conditions and two with 5000K bulbs to evaluate color management issues (calibration,
softproofing, and profiles).
I recommend to owners of my prints that they strongly consider using 3500K SoLux bulbs for display
and viewing.
To see, you need light. So it stands to reason that the light you view your prints in is extremely
important. All lights are not created equally. For the best results, choose a high quality light source.
SoLux bulb
Original posted by John Paul Caponigro at
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Spectral curves comparing 3500K halogen (yellow) and SoLux (red)
Spectral curves for 5000K fluorescent gti lightbox (blue) and SoLux (red)
Visit www.solux.net to find out more about their products and light (there are excellent resources
there on the science of light).
Contact Phil Bradfield – [email protected] or 800-254-4487.